TY - JOUR
A1 - Stratulat, C.
A1 - Ginghina, R. E.
A1 - Bratu, A. E.
A1 - Isleyen, A.
A1 - Tunc, M.
A1 - Hafner-Vuk, K.
A1 - Frey, A. M.
A1 - Kjeldsen, H.
A1 - Vogl, Jochen
T1 - Development- and Validation-Improved Metrological Methods for the Determination of Inorganic Impurities and Ash Content from Biofuels
N2 - In this study, five laboratories, namely, BRML (Romania), TUBITAK UME (Turkey), IMBIH (Bosnia and Herzegovina), BAM (Germany), and DTI (Denmark), developed and validated analytical procedures by ICP-MS, ICP-OES, MWP-AES, WD-XRF, and ID-MS for the determination of inorganic
impurities in solid and liquid biofuels, established the budget of uncertainties, and developed the method for determining the amount of ash in the measurement range 0–1.2% with absolute repeatability less than 0.1% and absolute reproducibility of 0.2% (according to EN ISO 18122). In order to create homogeneous certified reference materials, improved methodologies for the measurement and characterization of solid and liquid biofuels were developed. Thus, information regarding the precision, accuracy, and bias of the method, and identifying the factors that intervened in the measurement of uncertainty were experimentally determined, supplementing the information from the existing standards in the field.
KW - Development
KW - Validate method
KW - Biodiesel
KW - ICP-MS
KW - ICP-OES
KW - MW-AES
KW - WD-XRF
KW - ID-MS
KW - Inorganic impurities
KW - Ash content
KW - Wood chips
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-578743
DO - https://doi.org/10.3390/en16135221
VL - 16
IS - 13
SP - 1
EP - 14
PB - MDPI
AN - OPUS4-57874
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sun, C.
A1 - Schäferling, Michael
A1 - Resch-Genger, Ute
A1 - Gradzielski, M.
T1 - Solvothermal Synthesis of Lanthanide-doped NaYF4 Upconversion
N2 - Lanthanide-doped NaYF4 upconversion nano- and microcrystals were synthesized via a facile solvothermal approach. Thereby, the influence of volume ratios of ethylene glycol (EG)/H2O, molar ratios of NH4F/RE3+ (RE3+ represents the total amount of Y3+ and rare-earth dopant ions), Gd3+ ion contents, types of activator dopant ions, and different organic co-solvents on the crystal phase, size, and morphology of the resulting particles were studied systematically. A possible formation mechanism for the growth of crystals of different morphology is discussed. Our results show that the transition from the α- to the β-phase mainly depends on the volume ratio of EG/H2O and the molar ratio of NH4F/RE3+, while the morphology and size could be controlled by the type of organic co-solvent and Gd3+ dopant ions. Furthermore, the reaction time has to be long enough to convert α-NaYF4 into β-NaYF4 during the growth process to optimize the upconversion luminescence. The formation of larger β-NaYF4 crystals, which possess a higher upconversion luminescence than smaller particles, proceeds via intermediates of smaller crystals of cubic structure. In summary, our synthetic approach presents a facile route to tailor the size, Crystal phase, morphology, and luminescence features of upconversion
materials.
KW - Nano
KW - Nanomaterial
KW - Upconversion nanoparticle
KW - Photoluminescence
KW - Lanthanide
KW - Quantum yield
KW - Photophysics
KW - Lifetime
KW - Surface chemistry
KW - Single particle
KW - Brightness
KW - NIR
KW - Synthesis
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-520307
DO - https://doi.org/10.1002/cnma.202000564
VL - 7
IS - 2
SP - 174
EP - 183
PB - Wiley
AN - OPUS4-52030
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sun, Yijuan
A1 - Gawlitza, Kornelia
A1 - Valderrey, Virginia
A1 - Bell, Jérémy
A1 - Rurack, Knut
T1 - Polymerizable BODIPY probe crosslinker for the molecularly imprinted polymer-based detection of organic carboxylates via fluorescence
N2 - This contribution reports the development of a polymerizable BODIPY-type fluorescent probe targeting small-molecule carboxylates for incorporation into molecularly imprinted polymers (MIPs). The design of the probe crosslinker includes a urea recognition site p-conjugated to the 3-position of the BODIPY core and two methacrylate moieties. Titration experiments with a carboxylate-expressing antibiotic, levofloxacin (LEVO), showed a blue shift of the absorption band as well as a broadening and decrease in emission, attributed to hydrogen bonding between the probe’s urea group and the carboxylate group of the antibiotic. Using this probe crosslinker, core–shell particles with a silica core and a thin MIP shell were prepared for the detection of LEVO. The MIP exhibited highly selective recognition of LEVO, with an imprinting factor of 18.1 compared to the non-imprinted polymer. Transmission electron microscopy confirmed the core–shell structure and spectroscopic studies revealed that the receptor’s positioning leads to a unique perturbation of the polymethinic character of the BODIPY chromophore, entailing the favourable responses. These features are fully preserved in the MIP, whereas no such response was observed for competitors such as ampicillin. The sensory particles allowed to detect LEVO down to submicromolar concentrations in dioxane. We have developed here for the first time a BODIPY probe for organic carboxylates and incorporated it into polymers using the imprinting technique, paving the way for BODIPY-type fluorescent MIP sensors.
KW - Fluorescence
KW - BODIPY probe
KW - Molecularly Imprinted Polymers
KW - Sensor Materials
KW - Dyes
KW - Water analysis
KW - Advanced materials
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-598629
DO - https://doi.org/10.1039/D3MA00476G
SP - 1
EP - 11
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-59862
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sun, Yijuan
A1 - Gawlitza, Kornelia
A1 - Valderrey, Virginia
A1 - Bhattacharya, Biswajit
A1 - Rurack, Knut
T1 - Ratiometric Molecularly Imprinted Particle Probes for Reliable Fluorescence Signaling of Carboxylate-Containing Molecules
N2 - In addition to sensitivity, selectivity, and portability, chemical sensing systems must generate reliable signals and offer modular configurability to address various small molecule targets, particularly in environmental applications. We present a versatile, modular strategy utilizing ratiometric molecularly imprinted particle probes based on BODIPY indicators and dyes for recognition and internal referencing. Our approach employs polystyrene core particles doped with a red fluorescent BODIPY as an internal standard, providing built-in reference for environmental influences. A molecularly imprinted polymer (MIP) recognition shell, incorporating a green-fluorescent BODIPY indicator monomer with a thiourea binding site for carboxylate containing analytes, is grafted from the core particles in the presence of the analyte as the template. The dual-fluorescent MIP probe detects fexofenadine as the model analyte with a change in green emission signal referenced against a stable red signal, achieving a detection limit of 0.13 μM and a broad dynamic range from 0.16 μM to 1.2 mM, with good discrimination against other antibiotics in acetonitrile. By selecting a versatile dye scaffold and recognition element, this approach can be extended to other carboxylate-containing analytes and/or wavelength combinations, potentially serving as a robust multiplexing platform.
KW - Core-shell particles
KW - Molecular imprinting
KW - Pharmaceutical contaminants
KW - Self-referenced measurements
KW - Fluorescence
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-609385
DO - https://doi.org/10.1021/acsami.4c09990
SP - 1
EP - 13
PB - American Chemical Society (ACS)
AN - OPUS4-60938
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Sun, Yijuan
A1 - Pérez-Padilla, Víctor
A1 - Valderrey, Virginia
A1 - Bell, Jérémy
A1 - Gawlitza, Kornelia
A1 - Rurack, Knut
T1 - Ratiometric detection of perfluoroalkyl carboxylic acids using dual fluorescent nanoparticles and a miniaturised microfluidic platform
N2 - The widespread contamination of soil and water with perfluoroalkyl substances (PFAS) has caused considerable societal and scientific concern. Legislative measures and an increased need for remediation require effective on-site analytical methods for PFAS management. Here we report on the development of a green-fluorescent guanidine-BODIPY indicator monomer incorporated into a molecularly imprinted polymer (MIP) for the selective detection of perfluorooctanoic acid (PFOA). Complexation of PFOA by the indicator, which is mediated by concerted protonation-induced ion pairing-assisted hydrogen bonding, significantly enhances fluorescence in polar organic solvents. The MIP forms as a thin layer on silica nanoparticles doped with tris(bipyridine)ruthenium(II) chloride, which provides an orange emission signal as internal reference, resulting in low measurement uncertainties. Using a liquid-liquid extraction protocol, this assay enables the direct detection of PFOA in environmental water samples and achieves a detection limit of 0.11 µM. Integration into an opto-microfluidic system enables a compact and user-friendly system for detecting PFOA in less than 15 minutes.
KW - PFAS
KW - Molecular imprinting
KW - Microfluidics
KW - Fluorescence
KW - Onsite assay
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-650270
DO - https://doi.org/10.1038/s41467-025-66872-9
SN - 2041-1723
VL - 16
IS - 1
SP - 1
EP - 16
PB - Springer Science and Business Media LLC
AN - OPUS4-65027
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tang, Chi-Long
A1 - Seeger, Stefan
T1 - Measurement of sub-4 nm particle emission from FFF-3D printing with the TSI Nano Enhancer and the Airmodus Particle Size Magnifier
N2 - The emission of ultrafine particles from small desktop Fused Filament Fabrication (FFF) 3D printers has been frequently investigated in the past years. However, the vast majority of FFF emission and exposure studies have not considered the possible occurrence of particles below the typical detection limit of Condensation Particle Counters and could have systematically underestimated the total particle emission as well as the related exposure risks. Therefore, we comparatively measured particle number concentrations and size distributions of sub-4 nm particles with two commercially available diethylene glycol-based instruments – the TSI 3757 Nano Enhancer and the Airmodus A10 Particle Size Magnifier. Both instruments were evaluated for their suitability of measuring FFF-3D printing emissions in the sub-4 nm size range while operated as a particle counter or as a particle size spectrometer. For particle counting, both instruments match best when the Airmodus system was adjusted to a cut-off of 1.5 nm. For size spectroscopy, both instruments show limitations due to either the fast dynamics or rather low levels of particle emissions from FFF-3D printing in this range. The effects are discussed in detail in this article. The findings could be used to implement sub-4 nm particle measurement in future emission or exposure studies, but also for the development of standard test protocols for FFF-3D printing emissions.
KW - Air pollution
KW - Ultrafine particles
KW - Sub-4nm particles
KW - FFF-3D printing
KW - Emission testing
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-595952
DO - https://doi.org/10.1080/02786826.2024.2320430
SN - 0278-6826
VL - 58
IS - 6
SP - 644
EP - 656
PB - Taylor & Francis
CY - London
AN - OPUS4-59595
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tang, Chi-Long
A1 - Seeger, Stefan
A1 - Röllig, Mathias
T1 - Improving the comparability of FFF-3D printing emission data by adjustment of the set extruder temperature
N2 - Fused filament fabrication (FFF) is a material extrusion-based technique often used in desktop 3D printers. Polymeric filaments are melted and are extruded through a heated nozzle to form a 3D object in layers. The extruder temperature is therefore a key parameter for a successful print job but also one of the main emission driving factors as harmful pollutants (e.g., ultrafine particles) are formed by thermal polymer degradation. The awareness of potential health risks has increased the number of emission studies in the past years. However, studies usually refer their calculated emission data to the printer set extruder temperature for comparison purposes. In this study, we used a thermocouple and an infrared camera to measure the actual extruder temperature and found significant temperature deviations to the displayed set temperature among printer models. Our result shows that printing the same filament feedstocks with three different printer models and with identical printer set temperature resulted in a variation in particle emission of around two orders of magnitude. A temperature adjustment has reduced the variation to approx. one order of magnitude. Thus, it is necessary to refer the measured emission data to the actual extruder temperature as it poses a more accurate comparison parameter for evaluation of the indoor air quality in user scenarios or for health risk assessments.
KW - Ultrafine particles
KW - Infrared thermography
KW - Thermocouple
KW - Indoor air quality
KW - FFF-3D printer
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-572842
DO - https://doi.org/10.1016/j.aeaoa.2023.100217
VL - 18
SP - 100217
PB - Elsevier Ltd.
CY - Amsterdam, Niederlande
AN - OPUS4-57284
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tannenberg, Robert
A1 - Paul, Martin
A1 - Röder, Bettina
A1 - Gande, S. L.
A1 - Sreeramulu, S.
A1 - Saxena, K.
A1 - Richter, C.
A1 - Schwalbe, H.
A1 - Swart, C.
A1 - Weller, Michael G.
T1 - Chemiluminescence biosensor for the determination of cardiac troponin I (cTnI)
N2 - Cardiac troponin I (cTnI) is a crucial biomarker for diagnosing cardiac vascular diseases, including acute myocardial infarction (AMI). This study presents a proof-of-concept chemiluminescence-based immunosensor for rapid and accurate measurement of cTnI, with the potential for online monitoring. The immunosensor incorporates a flow cell design and a sensitive complementary metal-oxide-semiconductor (CMOS) camera for optical readout. A microfluidic setup was established to enable selective and quasi-online determination of cTnI within ten minutes. The sensor was tested with recombinant cTnI in phosphate buffer, demonstrating measurements in the concentration range of 2–25 µg/L, with a limit of detection (LoD) of 0.6 µg/L (23 pmol/L) achieved using the optimized system. The immunosensor exhibited high selectivity, as no cross-reactivity was observed with other recombinant proteins such as cTnT and cTnC at a concentration of 16 µg/L. Measurements with diluted blood plasma and serum yielded an LoD of 60 µg/L (2.4 nmol/L) and 70 µg/L (2.9 nmol/L), respectively. This biosensor offers a promising approach for the rapid and sensitive detection of cTnI, contributing to the diagnosis and management of acute myocardial infarction and other cardiac vascular diseases.
N2 - Das kardiale Troponin I (cTnI) ist ein wichtiger Biomarker für die Diagnose von Herz-Kreislauf-Erkrankungen, einschließlich des akuten Myokardinfarkts (AMI). In dieser Studie wird ein auf Chemilumineszenz basierender Immunsensor für die schnelle und genaue Messung von cTnI vorgestellt, der das Potenzial für eine Online-Überwachung hat. Der Immunsensor besteht aus einer Durchflusszelle und einer empfindlichen CMOS-Kamera (Complementary Metal-Oxide-Semiconductor) zur optischen Detektion. Es wurde ein mikrofluidischer Aufbau entwickelt, der eine selektive und quasi Online-Bestimmung von cTnI innerhalb von zehn Minuten ermöglicht. Der Sensor wurde mit rekombinantem cTnI in Phosphatpuffer getestet und zeigte einen Messbereich von 2-25 µg/L, wobei mit dem optimierten System eine Nachweisgrenze (LoD) von 0,6 µg/L (23 pmol/L) erreicht wurde. Der Immunsensor zeigte eine hohe Selektivität, da keine Kreuzreaktivität mit anderen rekombinanten Proteinen wie cTnT und cTnC bei einer Konzentration von 16 µg/L beobachtet wurde. Messungen mit verdünntem Blutplasma und Serum ergaben einen LoD von 60 µg/L (2,4 nmol/L) bzw. 70 µg/L (2,9 nmol/L). Dieser Biosensor bietet einen vielversprechenden Ansatz für den schnellen und empfindlichen Nachweis von cTnI, der zur Diagnose und Behandlung des akuten Myokardinfarkts und anderer kardialer Gefäßerkrankungen beitragen kann.
KW - Acute myocardial infarction
KW - Heart attack
KW - Emergency
KW - Diagnosis
KW - Cardiac troponin
KW - Biomarker
KW - Immunosensor
KW - Biosensor
KW - Chemiluminescence
KW - Luminol
KW - Peroxidase
KW - Monoclonal antibodies
KW - Flow injection immunoassay
KW - Immunometric assay
KW - Immunometric biosensor
KW - Microfluidic system
KW - Monolithic column
KW - Online biosensor
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-575471
DO - https://doi.org/10.3390/bios13040455
SN - 2079-6374
VL - 13
IS - 4
SP - 1
EP - 20
PB - MDPI
CY - Basel
AN - OPUS4-57547
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tatzel, M.
A1 - Frings, P. J.
A1 - Oelze, Marcus
A1 - Herwartz, D.
A1 - Lünsdorf, K.
A1 - Wiedenbeck, M.
T1 - Chert oxygen isotope ratios are driven by Earth's thermal evolution
N2 - The 18O/16O ratio of cherts (δ18Ochert) increases nearly monotonically by ~15‰ from the Archean to present. Two end-member explanations have emerged: cooling seawater temperature (TSW) and increasing seawater δ18O (δ18Osw). Yet despite decades of work, there is no consensus, leading some to view the δ18Ochert record as pervasively altered.
Here, we demonstrate that cherts are a robust archive of diagenetic temperatures, despite metamorphism and exposure to meteoric fluids, and show that the timing and temperature of quartz precipitation and thus δ18Ochert are determined by the kinetics of silica diagenesis. A diagenetic model shows that δ18Ochert is influenced by heat flow through the sediment column. Heat flow has decreased over time as planetary heat is dissipated, and reasonable Archean-modern heat flow changes account for ~5‰ of the increase in δ18Ochert, obviating the need for extreme TSW or δ18Osw reconstructions. The seawater oxygen isotope budget is also influenced by solid Earth cooling, with a recent reconstruction placing Archean δ18OSW 5 to 10‰ lower than today. Together, this provides an internally consistent view of the δ18Ochert record as driven by solid Earth cooling over billion-year timescales that is compatible with Precambrian glaciations and biological.
KW - Climate
KW - Oxygen isotope ratios
KW - Silica diagenesis
KW - Early Earth
KW - Heat flow
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-569359
DO - https://doi.org/10.1073/pnas.2213076119
SN - 0027-8424
VL - 119
IS - 51
SP - 1
EP - 7
PB - National Academy of Sciences
CY - Washington, DC
AN - OPUS4-56935
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tatzel, Michael
A1 - Oelze, Marcus
A1 - Frick, Daniel A.
A1 - Di Rocco, Tommaso
A1 - Liesegang, Moritz
A1 - Stuff, Maria
A1 - Wiedenbeck, Michael
T1 - Silicon and oxygen isotope fractionation in a silicified carbonate rock
N2 - Silicon isotope fractionation during silicification is poorly understood and impedes our ability to decipher paleoenvironmental conditions from Si isotopes in ancient cherts. To investigate isotope fractionation during silica-for-carbonate replacement we analyzed the microscale Si and O isotope composition in different silica phases in a silicified zebra dolostone as well as their bulk δ18O and Δ’17O compositions. The subsequent replacement of carbonate layers is mimicked by decreasing δ18O and δ30Si. The textural relationship and magnitude of Si and O isotope fractionation is best explained by near-quantitative silica precipitation in an open system with finite Si. A Rayleigh model for silicification suggests positive Ɛ30/28Si during silicification, conforming with predictions for isotope distribution at chemical equilibrium from ab-initio models. Application of the modelled Ɛ30Si-T relationship yields silicification temperatures of approx. 50°C. To reconcile the δ18Ochert composition with these temperatures, the δ18O of the fluid must have been between -2.5 and -4 ‰, compositions for which the quartz phases fall close to the oxygen equilibrium fractionation line in three-isotope space. Diagenetic silica replacement appears to occur in O and Si isotopic equilibrium allowing reconstructions of temperatures of silicification from Si isotopes and derive the δ18O composition of the fluid – a highly desired value needed for accurate reconstructions of the temperature- and δ18O histories of the oceans.
KW - Silicon isotopes
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603430
DO - https://doi.org/10.1016/j.chemgeo.2024.122120
SN - 0009-2541
VL - 658
SP - 1
EP - 13
PB - Elsevier B.V.
AN - OPUS4-60343
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tavernaro, Isabella
A1 - Rajotte, Isabelle
A1 - Thibeault, Marie-Pier
A1 - Sander, Philipp C.
A1 - Kodra, Oltion
A1 - Lopinski, Gregory
A1 - Radnik, Jörg
A1 - Johnston, Linda J.
A1 - Brinkmann, Andreas
A1 - Resch-Genger, Ute
T1 - Quantifying surface groups on aminated silica nanoparticles of different size, surface chemistry, and porosity with solution NMR, XPS, optical assays, and potentiometric titration
N2 - We assessed the quantification of surface amino functional groups (FGs) for a large set of commercial and custom-made aminated silica nanoparticles (SiO2 NPs) with sizes of 20–100 nm, prepared with different sol–gel routes, different amounts of surface amino FGs, and different porosity with four methods providing different, yet connected measurands in a bilateral study of two laboratories, BAM and NRC, with the overall aim to develop standardizable measurements for surface FG quantification. Special emphasis was dedicated to traceable quantitative magnetic resonance spectroscopy (qNMR) performed with dissolved SiO2 NPs. For the cost efficient and automatable screening of the amount of surface amino FGs done in a first step of this study, the optical fluorescamine assay and a potentiometric titration method were utilized by one partner, i.e., BAM, yielding the amount of primary amino FGs accessible for the reaction with a dye precursor and the total amount of (de)protonatable FGs. These measurements, which give estimates of the minimum and maximum number of surface amino FGs, laid the basis for quantifying the amount of amino silane molecules with chemo-selective qNMR with stepwise fine-tuned workflows, involving centrifugation, drying, weighting, dissolution, measurement, and data evaluation steps jointly performed by BAM and NRC. Data comparability and relative standard deviations (RSDs) obtained by both labs were used as quality measures for method optimization and as prerequisites to identify method-inherent limitations to be later considered for standardized measurement protocols. Additionally, the nitrogen (N) to silicon (Si) ratio in the near-surface region of the SiO2 NPs was determined by both labs using X-ray photoelectron spectroscopy (XPS), a well established surface sensitive analytical method increasingly utilized for microparticles and nano-objects which is currently also in the focus of international standardization activities. Overall, our results underline the importance of multi-method characterization studies for quantifying FGs on NMs involving at least two expert laboratories for effectively identifying sources of uncertainty, validating analytical methods, and deriving NM structure–property relationships.
KW - Advanced Materials
KW - Amino Groups
KW - Calibration
KW - Characterization
KW - Functional groups
KW - Method Comparison
KW - Nano Particle
KW - Validation
KW - XPS
KW - Optical Assay
KW - Quantification
KW - Surface Analysis
KW - Reference Materials
KW - Synthesis
KW - Fluorescence
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-649992
DO - https://doi.org/10.1039/d5na00794a
VL - 7
IS - 21
SP - 6888
EP - 6900
PB - Royal Society of Chemistry
AN - OPUS4-64999
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tavernaro, Isabella
A1 - Sander, P. C.
A1 - Andresen, Elina
A1 - Schedler, U.
A1 - Resch-Genger, Ute
T1 - Expanding the Toolbox of Simple, Cost-Efficient, and Automatable Methods for Quantifying Surface Functional Groups on Nanoparticles� Potentiometric Titration
N2 - Measuring surface functional groups (FGs) on nanomaterials (NMs) is essential for designing dispersible and stable NMs with tailored and predictable functionality. FG screening and quantification also plays a critical role for subsequent processing steps, NM long-term stability, quality control of NM production, and risk assessment studies and enables the implementation of sustainable and safe(r)-by-design concepts. This calls for simple and cost-efficient methods for broadly utilized FGs that can be ideally automated to speed up FG screening, monitoring, and quantification. To expand our NM surface analysis toolbox, focusing on simple methods and broadly available, cost-efficient instrumentation, we explored a NM-adapted pH titration method with potentiometric and optical readout for measuring the total number of (de)protonable FGs on representatively chosen commercial and custom-made aminated silica nanoparticles (SiO2 NPs). The accuracy and robustness of our stepwise optimized workflows was assessed by several operators in two laboratories and method validation was done by cross-comparison with two analytical methods relying on different signal generation principles. This included traceable, chemo-selective quantitative nuclear magnetic resonance spectroscopy (qNMR) and thermogravimetric analysis (TGA), providing the amounts of amino silanes released by particle dissolution and the total mass of the surface coatings. A comparison of the potentiometric titration results with the reporter-specific amounts of surface amino FGs determined with the previously automated fluorescamine (Fluram) assay highlights the importance of determining both quantities for surface-functionalized NMs. In the future, combined NM surface analysis with optical assays and pH titration will simplify quality control of NM production processes and stability studies and can yield large data sets for NM grouping that facilitates further developments in regulation and standardization.
KW - Quality assurance
KW - Fluorescence
KW - Nano
KW - Particle
KW - Synthesis
KW - Characterization
KW - Advanced material
KW - Surface
KW - Standardization
KW - Reference material
KW - Functional group
KW - Quantification
KW - Coating
KW - Automation
KW - Potentiometry
KW - Method
KW - Validation
KW - Optical assay
KW - Fluram
KW - Fluorescamine
KW - qNMR
KW - Comparison
KW - ILC
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-642371
DO - https://doi.org/10.1021/acsmeasuresciau.5c00062
SN - 2694-250X
SP - 1
EP - 13
PB - American Chemical Society
CY - Washington, DC
AN - OPUS4-64237
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tavernaro, Isabella
A1 - Simon, Fabian
A1 - Gehrenkemper, Lennart
A1 - Tobias, Charlie
A1 - Resch-Genger, Ute
A1 - Meermann, Björn
T1 - Quantification of the amount of surface groups of aminated silica nano- and microparticles utilizing a fluorine tag and HR-CS-GFMAS
N2 - The performance, bioavailability, and safe use of engineered nanomaterials (NMs) depends not only on properties such as size, shape, and surface area, but largely on surface chemistry. While many sizing methods have been established, there is still a lack of validated screening methods for determining NM surface functional groups (FGs). In this context, we present a fast and simple method for FG quantification using high resolution-continuum source-graphite furnace molecular absorption spectrometry (HR-CS-GFMAS) and assess its applicability for the surface analysis of representatively chosen aminated silica nanoparticles (NPs) and microparticles (MPs) in conjunction with amino FG labeling with a fluorine tag. For this proof-of-concept study, first surface amino FG screening of the silica NPs and MPs was done with a potentiometric back titration method, providing the total amount of protonatable surface FGs, and two optical assays relying on reporter dyes with sizes and spatial requirements, i.e., surface binding areas smaller or larger than that of the fluorine tag to estimate the maximum and reporter-accessible number of amino FGs. Subsequently, the surface amino FGs were labeled with the fluorine tag 4-(trifluoromethyl)benzoic acid (TFMB) and the amount of fluorine originating from the bound TFMB molecules was quantified by HR-CS-GFMAS in two common organic solvents, i.e., dimethyl sulfoxide (DMSO) or ethanol (EtOH) to assess possible interferences from organic matrices. Our study revealed limits of detection (LODs) and quantification (LOQs) for fluorine of 1.0 µg/L and 3.5 µg/L in EtOH and 1.5 µg/L and 5.0 µg/L in DMSO, respectively. Overall, a quick and simple method for analyzing surface FGs on NPs and MPs was presented utilizing broadly available fluorine tags and HR-CS-GFMAS for fluorine quantification, which can be applied, e.g., for homogeneity, stability, and aging studies of surface-modified particles. This could contribute to ease the understanding of property-safety relationships for surface-functionalized NMs.
KW - Fluorine Analysis
KW - Nano- and microparticles
KW - Surface group quantification
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-641965
DO - https://doi.org/10.1007/s00216-025-06107-4
SN - 1618-2642
SP - 1
EP - 11
PB - Springer Science and Business Media LLC
CY - Berlin ; Heidelberg
AN - OPUS4-64196
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tchipilov, Teodor
A1 - Meyer, Klas
A1 - Weller, Michael G.
T1 - Quantitative 1H nuclear magnetic resonance (qNMR) of aromatic amino acids for protein quantification
N2 - Hydrolysis of protein samples into amino acids facilitates the use of NMR spectroscopy for protein and peptide quantification. Different conditions have been tested for quantifying aromatic amino acids and proteins. The pH-dependent signal shifts in the aromatic region of amino acid samples were examined. A pH of 12 was found to minimize signal overlap of the four aromatic amino acids. Several aromatic compounds, such as terephthalic acid, sulfoisophthalic acid, and benzene tricarboxylic acid, were applied as internal standards. The quantification of amino acids from an amino acid standard was performed. Using the first two suggested internal standards, recovery was ~97% for histidine, phenylalanine, and tyrosine at a concentration of approximately 1 mM in solution. Acidic hydrolysis of a certified reference material (CRM) of bovine serum albumin (BSA) and subsequent quantification of Phe and Tyr yielded recoveries of 98% ± 2% and 88% ± 4%, respectively, at a protein concentration of 16 g/L or 250 µM.
KW - Amino acid analysis
KW - Aromatic amino acid analysis
KW - AAA
KW - AAAA
KW - Protein hydrolysis
KW - Hydrochloric acid
KW - Metrology
KW - Traceability
KW - NIST
KW - Reference materials
KW - Internal standard
KW - Calibration
KW - Compound-independent calibration
KW - Histidine
KW - Tyrosine
KW - Tryptophan
KW - Phenylalanine
KW - Terephthalic acid
KW - Benzene-1,3,5-tricarboxylic acid
KW - Bovine serum albumin (BSA)
KW - Quantitative protein analysis
KW - Phenylketonuria
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-570943
DO - https://doi.org/10.3390/mps6010011
VL - 6
IS - 1
SP - 1
EP - 13
PB - MDPI
CY - Basel, Schweiz
AN - OPUS4-57094
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Temgoua, Ranil C.T.
A1 - Dontsi, Fabiola T.
A1 - Lebègue, Estelle
A1 - Thobie-Gautier, Christine
A1 - Tonlé, Ignas K.
A1 - Boujtita, Mohammed
T1 - Understanding the behavior of phenylurazole-tyrosine-click electrochemical reaction using hybrid electroanalytical techniques
N2 - In this work, the electrochemical behavior of 4-phenylurazole (Ph-Ur) was studied and the latter was used as a molecular anchor for the electrochemical bioconjugation of tyrosine (Y). Cyclic voltammetry (CV) and controlled potential coulometry (CPC) allowed the in-situ generation of the PTAD (4-phenyl-3 H-1,2,4-triazole-3,5(4 H)-dione) species from phenylurazole on demand for tyrosine electrolabeling. The chemoselectivity of the reaction was studied with another amino acid (lysine, Lys) and no changes in Lys were observed. To evaluate the performance of tyrosine electrolabeling, coulometric analyses at controlled potentials were performed on solutions of phenylurazole and the phenylurazole-tyrosine mixture in different proportions (2:1, 1:1, and 1:2). The electrolysis of the phenylurazole-tyrosine mixture in the ratio (1:2) produced a charge of 2.07 C, very close to the theoretical value (1.93 C), with high reaction kinetics, a result obtained here for the first time. The products obtained were identified and characterized by liquid chromatography coupled to high-resolution electrospray ionization mass spectrometry (LC-HRMS and LC- HRMS2). Two products were formed from the click reactions, one of which was the majority. Another part of this work was to study the electrochemical degradation of the molecular anchor 4-phenylazole (Ph-Ur). Four stable degradation products of phenylurazole were identified (C7H9N2O, C6H8N, C6H8NO, C14H13N4O2) based on chromatographic profiles and mass spectrometry results. The charge generated during the electrolysis of phenylurazole (two-electron process) (2.85 C) is inconsistent with the theoretical or calculated charge (1.93 C), indicating that secondary/parasitic reactions occurred during the electrolysis of the latter. In conclusion, the electrochemically promoted click phenylurazole-tyrosine reactions give rise to click products with high reaction kinetics and yields in the (1:2) phenylurazole-tyrosine ratios, and the presence of side reactions is likely to affect the yield of the click phenylurazole-tyrosine reaction.
KW - Clinical Biochemistry
KW - Spectroscopy
KW - Drug Discovery
KW - Pharmaceutical Science
KW - Analytical Chemistry
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-599267
DO - https://doi.org/10.1016/j.jpba.2024.116147
VL - 245
SP - 1
EP - 8
PB - Elsevier BV
AN - OPUS4-59926
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Thiele, Isabel
A1 - Santolin, Lara
A1 - Meyer, Klas
A1 - Machatschek, Rainhard
A1 - Bölz, Uwe
A1 - Tarazona, Natalia A.
A1 - Riedel, Sebastian L.
T1 - Microbially synthesized poly(hydroxybutyrate-co-hydroxyhexanoate) with low to moderate hydroxyhexanoate content: Properties and applications
N2 - Plastic pollution is the biggest environmental concern of our time. Breakdown products like micro- and nanoplastics inevitably enter the food chain and pose unprecedented health risks. In this scenario, bio-based and biodegradable plastic alternatives have been given a momentum aiming to bridge a transition towards a more sustainable future. Polyhydroxyalkanoates (PHAs) are one of the few thermoplastic polymers synthesized 100 % via biotechnological routes which fully biodegrade in common natural environments. Poly(hydroxybutyrate-cohydroxyhexanoate) [P(HB-co-HHx)] is a PHA copolymer with great potential for the commodity polymers industry, as its mechanical properties can be tailored through fine-tuning of its molar HHx content. We have recently developed a strategy that enables for reliable tailoring of the monomer content of P(HB-co-HHx).
Nevertheless, there is often a lack of comprehensive investigation of the material properties of PHAs to evaluate whether they actually mimic the functionalities of conventional plastics. We present a detailed study of P(HB-co-HHx) copolymers with low to moderate hydroxyhexanoate content to understand how the HHx monomer content influences the thermal and mechanical properties and to link those to their abiotic degradation. By increasing the HHx fractions in the range of 2 – 14 mol%, we impart an extension of the processing window and application range as the melting temperature (Tm) and glass temperature (Tg) of the copolymers decrease from Tm 165 ◦C to 126 ◦C, Tg 4 ◦C to − 5.9 ◦C, accompanied by reduced crystallinity from 54 % to 20 %.
Elongation at break was increased from 5.7 % up to 703 % at 14 mol% HHx content, confirming that the range examined was sufficiently large to obtain ductile and brittle copolymers, while tensile strength was maintained throughout the studied range. Finally, accelerated abiotic degradation was shown to be slowed down with an increasing HHx fraction decreasing from 70 % to 55 % in 12 h.
KW - Molecular Biology
KW - General Medicine
KW - Biochemistry
KW - Structural Biology
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-595636
DO - https://doi.org/10.1016/j.ijbiomac.2024.130188
VL - 263
SP - 1
EP - 9
PB - Elsevier B.V.
AN - OPUS4-59563
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Thiele, Isabel
A1 - Weiske, Björn
A1 - Riedel, Sebastian L.
A1 - Meyer, Klas
T1 - On-line monitoring of polyhydroxyalkanoate extraction by low-field nuclear magnetic resonance spectroscopy
N2 - The use of low-field nuclear magnetic resonance (NMR) spectroscopy enables real-time reaction monitoring in contrast to time-consuming gas chromatography or off-line high-field NMR measurements. In this study, NMR spectroscopy is demonstrated as a novel process analytical technology (PAT) tool in the downstream processing of polyhydroxyalkanoate (PHA) biopolymers. On-line NMR spectroscopy measurements were performed using a Spinsolve 43 Carbon Ultra instrument in a fully automated mode with a flow-assembly based on PTFE tubing. Single-scan NMR spectra were acquired for real-time monitoring of the extraction process of the PHA copolymer poly(hydroxybutyrate-co-hydroxyhexanoate) with 13.5 mol.% hydroxyhexanoate [P(HB-co-13.5 mol.%HHx)] from Ralstonia eutropha biomass using chloroform or acetone as PHA solvents at lyophilized cell loadings of 20–120 g L 1. The reproducibility and reliability of low-field NMR spectroscopy was comparable to high-field NMR spectroscopy, with superior performance in terms of time. The correlation between the results of on-line monitoring using low-field NMR spectroscopy and off-line analysis using gas chromatography (GC) showed a correlation coefficient of >94 %. The versatility of low-field NMR spectroscopy for elucidating reaction kinetics, facilitating endpoint determination and accelerating extraction processes by maximizing solubility is highlighted as plateau values were reached within 6–10 min for chloroform and acetone, respectively. This novel low-field NMR spectroscopy application promotes a new monitoring approach for downstream PHA processing and supports process development and optimization.
KW - Polyhydroxyalkanoate
KW - Extraction
KW - NMR
KW - Ralstonia eutropha
KW - Downstream processing
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-624215
DO - https://doi.org/10.1016/j.polymdegradstab.2025.111188
SN - 1873-2321
VL - 233
SP - 1
EP - 10
PB - Elsevier Ltd.
CY - Amsterdam
AN - OPUS4-62421
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tjaden, B.
A1 - Lisec, Jan
A1 - Schramm, A.
T1 - N-Myc-induced metabolic rewiring creates novel therapeutic vulnerabilities in neuroblastoma
N2 - N-Myc is a transcription factor that is aberrantly expressed in many tumor types and is often correlated with poor patient prognosis. Recently, several lines of evidence pointed to the fact that oncogenic activation of Myc family proteins is concomitant with reprogramming of tumor cells to cope with an enhanced need for metabolites during cell growth. These adaptions are driven by the ability of Myc proteins to act as transcriptional amplifiers in a tissue-of-origin specific manner. Here, we describe the effects of N-Myc overexpression on metabolic reprogramming in neuroblastoma cells. Ectopic expression of N-Myc induced a glycolytic switch that was concomitant with enhanced sensitivity towards 2-deoxyglucose, an inhibitor of glycolysis. Moreover, global metabolic profiling revealed extensive alterations in the cellular metabolome resulting from overexpression of N-Myc. Limited supply with either of the two main carbon sources, glucose or glutamine, resulted in distinct shifts in steady-state metabolite levels and significant changes in glutathione metabolism. Interestingly, interference with glutamine-glutamate conversion preferentially blocked proliferation of N-Myc overexpressing cells, when glutamine levels were reduced. Thus, our study uncovered N-Myc induction and nutrient levels as important metabolic master switches in neuroblastoma cells and identified critical nodes that restrict tumor cell proliferation.
KW - Mass-Spectrometry
KW - Cancer
KW - MYCN
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-507193
DO - https://doi.org/10.1038/s41598-020-64040-1
VL - 10
IS - 1
SP - 7157
AN - OPUS4-50719
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tobias, Charlie
A1 - Gehrenkemper, Lennart
A1 - Bernstein, Thomas
A1 - Schlau, Sven
A1 - Simon, Fabian
A1 - Röllig, Mathias
A1 - Meermann, Björn
A1 - von der Au, Marcus
T1 - Development of a fully automated slurry sampling introduction system for GF-AAS and its application for the determination of cadmium in different matrices
N2 - element analysis, offering high sensitivity and precision. However, its effectiveness is limited by sample preparation challenges for solid samples like soils and microplastics. Traditional methods include sample preparation, such as digestion, which is time-consuming and involves reagents, like acids, contributing to measurement uncertainty and higher carbon footprints. Slurry sampling allows direct analysis of suspensions, offering a more efficient alternative. However, maintaining suspension stability is challenging, requiring robust autosampler systems to streamline the process and enhance analytical performance.
Results: We present a novel autosampler extension for slurry sample introduction into GF-AAS. This system ensures suspension stability with a stirring device and closed vessels to prevent evaporation and contamination, incorporating a cooling unit to reduce solvent and analyte losses. It installs and removes in minutes without
additional connections. Validation with cadmium analysis in BAM-U110 (Soil) and BAM-H010 (ABS) showed high reliability. For BAM-U110 (Soil), we achieved recovery rates of 94 % ± 13 % in water suspension. The recovery rate for BAM-H010 (ABS) was 104 % ±11 % in acetonitrile suspension. These results demonstrate the system’s robustness, versatility, and accuracy for different matrices.
Significance:
The autosampler extension helps solve key problems in trace element analysis of solid samples, making the process faster and more accurate. It works well with complex materials, making it useful for areas like microplastic or nanoparticle analysis. This improvement also helps meet regulations for monitoring environ mental and polymer samples, offering a reliable and flexible tool for high-throughput analysis with fewer errors.
KW - Slurry AAS
KW - Soil
KW - Cd
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-618531
DO - https://doi.org/10.1016/j.aca.2024.343460
SN - 0003-2670
VL - 1335
SP - 1
EP - 7
PB - Elsevier BV
AN - OPUS4-61853
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tobias, Charlie
A1 - López-Puertollano, Daniel
A1 - Abad-Somovilla, Antonio
A1 - Mercader, J. V.
A1 - Abad-Fuentes, A.
A1 - Rurack, Knut
T1 - Development of Simple and Rapid Bead-Based Cytometric Immunoassays Using Superparamagnetic Hybrid Core−Shell Microparticles
N2 - Flow cytometry-based immunoassays are valuable in biomedical research and clinical applications due to their high throughput and multianalyte capability, but their adoption in areas such as food safety and environmental monitoring is limited by long assay times and complex workflows. Rapid, simplified bead-based cytometric immunoassays are needed to make these methods viable for point-of-need applications, especially with the increasing accessibility of miniaturized cytometers. This work introduces superparamagnetic hybrid polystyrene-silica core−shell microparticles as promising alternatives to conventional polymer beads in competitive cytometric immunoassays. These beads, featuring high specificity, sensitivity, and excellent handling capabilities via magnetic separation, were evaluated with three different antibodies and binding methods, showing variations in signal intensity based on the antibody and its attachment method. The optimal performance was achieved through a secondary antibody binding approach, providing strong and consistent signals with minimal uncertainty. The optimized protocol made it possible to achieve a detection limit of 0.025 nM in a total assay time of only 15 min and was successfully used to detect ochratoxin A (OTA) in raw flour samples. This work highlights the potential of these beads as versatile tools for flow cytometry-based immunoassays, with significant implications for food safety, animal health,
environmental monitoring, and clinical diagnostics.
KW - Immunoassays
KW - Bead-based
KW - Core-shell particles
KW - Cytometry
KW - Mycotoxins
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-610593
DO - https://doi.org/10.1021/acsmeasuresciau.4c00038
SP - 1
EP - 11
PB - American Chemical Society
CY - Washington, D.C.
AN - OPUS4-61059
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tscheuschner, Georg
A1 - Kaiser, Melanie N.
A1 - Lisec, Jan
A1 - Beslic, D.
A1 - Muth, Thilo
A1 - Krüger, M.
A1 - Mages, H. W.
A1 - Dorner, B. G.
A1 - Knospe, J.
A1 - Schenk, J. A.
A1 - Sellrie, F.
A1 - Weller, Michael G.
T1 - MALDI-TOF-MS-Based Identification of Monoclonal Murine Anti-SARS-CoV-2 Antibodies within One Hour
N2 - During the SARS-CoV-2 pandemic, many virus-binding monoclonal antibodies have been developed for clinical and diagnostic purposes. This underlines the importance of antibodies as universal bioanalytical reagents. However, little attention is given to the reproducibility crisis that scientific studies are still facing to date. In a recent study, not even half of all research antibodies mentioned in publications could be identified at all. This should spark more efforts in the search for practical solutions for the traceability of antibodies. For this purpose, we used 35 monoclonal antibodies against SARS-CoV-2 to demonstrate how sequence-independent antibody identification can be achieved by simple means applied to the protein. First, we examined the intact and light chain masses of the antibodies relative to the reference material NIST-mAb 8671. Already half of the antibodies could be identified based solely on these two parameters. In addition, we developed two complementary peptide mass fingerprinting methods with MALDI-TOF-MS that can be performed in 60 min and had a combined sequence coverage of over 80%. One method is based on the partial acidic hydrolysis of the protein by 5 mM of sulfuric acid at 99 degrees C. Furthermore, we established a fast way for a tryptic digest without an alkylation step. We were able to show that the distinction of clones is possible simply by a brief visual comparison of the mass spectra. In this work, two clones originating from the same immunization gave the same fingerprints. Later, a hybridoma sequencing confirmed the sequence identity of these sister clones. In order to automate the spectral comparison for larger libraries of antibodies, we developed the online software ABID 2.0. This open-source software determines the number of matching peptides in the fingerprint spectra. We propose that publications and other documents critically relying on monoclonal antibodies with unknown amino acid sequences should include at least one antibody fingerprint. By fingerprinting an antibody in question, its identity can be confirmed by comparison with a library spectrum at any time and context.
KW - Reproducibility
KW - Quality control
KW - Traceability
KW - Peptides
KW - Peptide mass fingerprinting
KW - Monoclonal antibody
KW - Recombinant antibody
KW - Identity
KW - Antibody identification
KW - Sequencing
KW - Light chain
KW - Mass spectrometry
KW - Software
KW - Open science
KW - Library
KW - COVID-19
KW - Corona virus
KW - Sequence coverage
KW - NIST-mAb 8671
KW - Reference material
KW - RBD
KW - Spike protein
KW - Nucleocapsid
KW - Cleavage
KW - Tryptic digest
KW - MALDI
KW - DHAP
KW - 2,5-dihydroxyacetophenone
KW - Github
KW - Zenodo
KW - ABID
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-547347
DO - https://doi.org/10.3390/antib11020027
VL - 11
IS - 2
SP - 1
EP - 22
PB - MDPI
CY - Basel
AN - OPUS4-54734
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tscheuschner, Georg
A1 - Ponader, Marco
A1 - Raab, Christopher
A1 - Weider, Prisca S.
A1 - Hartfiel, Reni
A1 - Kaufmann, Jan Ole
A1 - Völzke, Jule L.
A1 - Bosc-Bierne, Gaby
A1 - Prinz, Carsten
A1 - Schwaar, T.
A1 - Andrle, Paul
A1 - Bäßler, Henriette
A1 - Nguyen, Khoa
A1 - Zhu, Y.
A1 - Mey, A. S. J. S.
A1 - Mostafa, A.
A1 - Bald, I.
A1 - Weller, Michael G.
T1 - Efficient Purification of Cowpea Chlorotic Mottle Virus by a Novel Peptide Aptamer
N2 - The cowpea chlorotic mottle virus (CCMV) is a plant virus explored as a nanotechnological platform. The robust self-assembly mechanism of its capsid protein allows for drug encapsulation and targeted delivery. Additionally, the capsid nanoparticle can be used as a programmable platform to display different molecular moieties. In view of future applications, efficient production and purification of plant viruses are key steps. In established protocols, the need for ultracentrifugation is a significant limitation due to cost, difficult scalability, and safety issues. In addition, the purity of the final virus isolate often remains unclear. Here, an advanced protocol for the purification of the CCMV from infected plant tissue was developed, focusing on efficiency, economy, and final purity. The protocol involves precipitation with PEG 8000, followed by affinity extraction using a novel peptide aptamer. The efficiency of the protocol was validated using size exclusion chromatography, MALDI-TOF mass spectrometry, reversed-phase HPLC, and sandwich immunoassay. Furthermore, it was demonstrated that the final eluate of the affinity column is of exceptional purity (98.4%) determined by HPLC and detection at 220 nm. The scale-up of our proposed method seems to be straightforward, which opens the way to the large-scale production of such nanomaterials. This highly improved protocol may facilitate the use and implementation of plant viruses as nanotechnological platforms for in vitro and in vivo applications.
N2 - Das Cowpea Chlorotic Mottle Virus (CCMV) ist ein Pflanzenvirus, das als nanotechnologische Plattform erforscht wird. Der robuste Selbstorganisationsmechanismus seines Kapsidproteins ermöglicht die Verkapselung und gezielte Abgabe von Medikamenten. Darüber hinaus kann das Kapsid-Nanopartikel als programmierbare Plattform für die Präsentation verschiedener molekularer Komponenten verwendet werden. Im Hinblick auf künftige Anwendungen ist eine effiziente Produktion und Reinigung von Pflanzenviren von entscheidender Bedeutung. In etablierten Protokollen stellt die notwendige Ultrazentrifugation aufgrund von Kosten, schwieriger Skalierbarkeit und Sicherheitsaspekten eine erhebliche Einschränkung dar. Darüber hinaus bleibt die Reinheit des endgültigen Virusisolats oft unklar. Hier wurde ein fortschrittliches Protokoll für die Reinigung von CCMV aus infiziertem Pflanzengewebe entwickelt, wobei der Schwerpunkt auf Effizienz, Wirtschaftlichkeit und Reinheit lag. Das Protokoll beinhaltet eine Fällung mit Polyethylenglycol (PEG 8000), gefolgt von einer Affinitätsextraktion mit einem neuartigen Peptid-Aptamer. Die Effizienz des Protokolls wurde mithilfe von Größenausschluss-Chromatographie (SEC), MALDI-TOF-Massenspektrometrie, Umkehrphasen-HPLC und Sandwich-Immunoassay validiert. Darüber hinaus wurde nachgewiesen, dass das endgültige Eluat der Affinitätssäule eine außergewöhnliche Reinheit (98,4 %) aufweist, die durch HPLC und Detektion bei 220 nm bestimmt wurde. Die Skalierung der von uns vorgeschlagenen Methode scheint einfach zu sein, was den Weg für eine größer angelegte Produktion solcher Nanomaterialien ebnet. Dieses stark verbesserte Protokoll könnte die Verwendung und Umsetzung von Pflanzenviren als nanotechnologische Plattformen für In-vitro- und In-vivo-Anwendungen erleichtern.
KW - Affinity chromatography
KW - Nanoparticles
KW - Nanoscience
KW - Carrier protein
KW - Encapsulation
KW - Combinatorial peptide library
KW - Peptide binder
KW - Vigna unguiculata
KW - Augenbohne
KW - Schlangenbohne
KW - Pflanzenvirus
KW - Plant virus
KW - Upscaling
KW - Commercialization
KW - Reference material
KW - Nanocarrier
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-572645
DO - https://doi.org/10.3390/v15030697
VL - 15
IS - 3
SP - 1
EP - 24
PB - MDPI
CY - Basel, Schweiz
AN - OPUS4-57264
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tscheuschner, Georg
A1 - Schwaar, Timm
A1 - Weller, Michael G.
T1 - Fast Confirmation of Antibody Identity by MALDI-TOF MS Fingerprints
N2 - Thousands of antibodies for diagnostic and other analytical purposes are on the market. However, it is often difficult to identify duplicates, reagent changes, and to assign the correct original publications to an antibody. This slows down scientific progress and might even be a cause of irreproducible research and a waste of resources. Recently, activities were started to suggest the sole use of recombinant antibodies in combination with the open communication of their sequence. In this case, such uncertainties should be eliminated. Unfortunately, this approach seems to be rather a long-term vision since the development and manufacturing of recombinant antibodies remain quite expensive in the foreseeable future. Nearly all commercial antibody suppliers also may be reluctant to publish the sequence of their antibodies, since they fear counterfeiting. De novo sequencing of antibodies is also not feasible today for a reagent user without access to the hybridoma clone. Nevertheless, it seems to be crucial for any scientist to have the opportunity to identify an antibody undoubtedly to guarantee the traceability of any research activity using antibodies from a third party as a tool. For this purpose, we developed a method for the identification of antibodies based on a MALDI-TOF MS fingerprint. To circumvent lengthy denaturation, reduction, alkylation, and enzymatic digestion steps, the fragmentation was performed with a simple formic acid hydrolysis step. Eighty-nine unknown monoclonal antibodies were used for this study to examine the feasibility of this approach. Although the molecular assignment of peaks was rarely possible, antibodies could be easily recognized in a blinded test, simply from their mass-spectral fingerprint. A general protocol is given, which could be used without any optimization to generate fingerprints for a database. We want to propose that, in most scientific projects relying critically on antibody reagents, such a fingerprint should be established to prove and document the identity of the used antibodies, as well as to assign a specific reagent to a datasheet of a commercial supplier, public database record, or antibody ID.
KW - Reproducibility
KW - Quality Control
KW - Traceability
KW - Diagnostics
KW - Hybridoma
KW - Monoclonal Antibody
KW - Recombinant Antibody
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-506611
DO - https://doi.org/10.3390/antib9020008
SN - 2073-4468
VL - 9
IS - 2
SP - 1
EP - 17
PB - MDPI
CY - Basel
AN - OPUS4-50661
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tukhmetova, Dariya
A1 - Langhammer, Nicole
A1 - Vogl, Jochen
A1 - Meermann, Björn
T1 - Online Isotope Analysis of Sulfur in Proteins via Capillary Electrophoresis Coupled With Multicollector ICP‐MS (CE/MC‐ICP‐MS): A Proof of Concept Study
N2 - Isotope ratio analysis of sulfur in biological samples using inductively coupled plasma-mass spectrometry (ICP-MS) has gained significant interest for applications in quantitative proteomics. Advancements like coupling separation techniques with multicollector ICP-MS (MC-ICP-MS) enhance the throughput of species-specific sulfur isotope ratio measurements, fostering new avenues for studying sulfur metabolism in complex biological matrices. This proof-of-concept study investigates the feasibility of online CE/MC-ICP-MS for directly analyzing sulfur isotope ratios in proteins (albumin). Leveraging our previous work on the applicability of CE/ICP-MS for quantifying sulfur-containing biological molecules, we explore its potential for sulfur isotope analysis. Our results demonstrate that direct analysis of sulfur isotopes in albumin protein using online capillary electrophoresis MC-ICP-MS (CE/MC-ICP-MS) eliminates the need for laborious pretreatment steps, while yielding isotope ratios comparable to the reference values. Although initial precision can be improved through further system optimization and protein injection techniques, this approach paves the way for future analysis of mixtures of various biological compounds in, for example, clinical diagnosis studies.
KW - Isotope analysis
KW - Sulfur
KW - CE/MC-ICP-MS
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-612439
DO - https://doi.org/10.1002/elps.202400128
SN - 0173-0835
SP - 1
EP - 6
PB - Wiley-Blackwell
CY - Weinheim
AN - OPUS4-61243
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tukhmetova, Dariya
A1 - Lisec, Jan
A1 - Vogl, Jochen
A1 - Meermann, Björn
T1 - Data processing made easy: standalone tool for automated calculation of isotope ratio from transient signals – IsoCor
N2 - Despite numerous advantages offered by hyphenation of chromatography and electrokinetic separation methods with multicollector (MC) ICP-MS for isotope analysis, the main limitation of such systems is the decrease in precision and increase in uncertainty due to generation of short transient signals. To minimize this limitation, most authors compare several isotope ratio calculation methods and establish a multi-step data processing routine based on the precision and accuracy of the methods. However, to the best of our knowledge, there is no universal data processing tool available that incorporates all important steps of the treatment of the transient signals. Thus, we introduce a data processing application (App) IsoCor that facilitates automatic calculation of isotope ratios from transient signals and eases selection of the most suitable method. The IsoCor App performs baseline subtraction, peak detection, mass bias correction, isotope ratio calculation and delta calculation. The feasibility and reliability of the App was proven by reproducing the results from isotope analysis of three elements (neodymium, mercury and sulfur) measured on-line via hyphenated systems. The IsoCor App provides trackability of the results to ensure quality control of the analysis.
KW - Isotope ratio
KW - Transient signal
KW - MC-ICP-MS
KW - Data processing
KW - App
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559068
DO - https://doi.org/10.1039/D2JA00208F
VL - 37
IS - 11
SP - 2401
EP - 2409
PB - Royal Society of Chemistry
AN - OPUS4-55906
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tukhmetova, Dariya
A1 - Lisec, Jan
A1 - Vogl, Jochen
A1 - Meermann, Björn
T1 - Development of an Online Isotope Dilution CE/ICP–MS Method for the Quantification of Sulfur in Biological Compounds
N2 - We report an analytical methodology for the quantification of sulfur in biological molecules via a speciesunspecific postcolumn isotope dilution (online ID) approach using capillary electrophoresis (CE) coupled online with inductively coupled plasma−mass spectrometry (online ID CE/ICP−MS).
The method was optimized using a mixture of standard compounds including sulfate, methionine, cysteine, cystine, and albumin, yielding compound recoveries between 98 and 105%. The quantity of sulfur is further converted to the quantity of the compounds owing to the prior knowledge of the sulfur content in the molecules. The limit of detection and limit of quantification of sulfur in the compounds were 1.3−2.6 and 4.1−8.4 mg L−1, respectively, with a correlation coefficient of 0.99 within the concentration range of sulfur of 5−100 mg L−1. The capability of the method was extended to quantify albumin in its native matrix (i.e., in serum) using experimentally prepared serum spiked with a pure albumin standard for validation. The relative expanded uncertainty of the method for the quantification of albumin was 6.7% (k = 2). Finally, we tested the applicability of the method on real samples by the analysis of albumin in bovine and human sera. For automated data assessment, a software application (IsoCor) which was developed by us in a previous work was developed further for handling of online ID data. The method has several improvements compared to previously published setups: (i) reduced adsorption of proteins onto the capillary wall owing to a special capillary-coating procedure, (ii) baseline separation of the compounds in less than 30 min via CE, (iii) quantification of several sulfur species within one run by means of the online setup, (iv) SI traceability of the quantification results through online ID, and (v) facilitated data processing of the transient signals using the IsoCor application. Our method can be used as an accurate approach for quantification of proteins and other biological molecules via sulfur analysis in complex matrices for various fields, such as environmental, biological, and pharmaceutical studies as well as clinical diagnosis.
Sulfur is an essential element in living organisms, where it plays important roles in various biological processes, such as protein synthesis, enzyme activity, and antioxidant defense. However, the biological effects of different sulfur species can vary widely, and imbalances in sulfur speciation have been observed in a range of diseases, including cancer, Alzheimer’s disease, and diabetes.1−3 The accurate quantification of sulfur and its species in biological samples requires sensitive and selective analytical techniques. In recent years, separation techniques coupled online with inductively coupled plasma−mass spectrometry (ICP−MS) have emerged as powerful online analytical tools complementary to molecular spectrometric methods for speciation analysis of biological compounds.
External calibration4−9 and isotope dilution (ID)10−15 are common calibration approaches applied for online quantification of sulfur species in complex samples. The ID analysis is advantageous over.
KW - Analytical Chemistry
KW - CE/MC-ICP-MS
KW - species-specific isotope information
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-594736
DO - https://doi.org/10.1021/acs.analchem.3c03553
SN - 0003-2700
SP - 1
EP - 8
PB - American Chemical Society (ACS)
AN - OPUS4-59473
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tuma, Dirk
A1 - Mady, A. H.
A1 - Baynosa, M. L.
A1 - Saad, M.
A1 - Dhakal, G.
A1 - Kim, W. K.
A1 - Shim, Jae-Jin
T1 - Morphology-engineered hollow NiTiO₃/C–Ag/Ag₃PO₄ S-scheme heterojunction photocatalyst: mechanistic insights into sunlight-driven tetracycline degradation
N2 - Tetracycline (TCH), a widely used antibiotic, persists in aquatic and terrestrial environments, posing ecological risks and accelerating antibiotic resistance. To address this, we report a hollow-structured NiTiO₃/C–Ag/Ag₃PO₄ (NT/C–AAP)
photocatalyst—the first hollow-type nickel titanate—synthesized via a self-template solvothermal route followed by photodeposition. The catalyst integrates key design strategies—hollow architecture, oxygen vacancies, carbon coating, and an S-scheme heterojunction—to optimize photocatalytic performance. The hollow structure enhances light harvesting via internal scattering, oxygen vacancies facilitate O2 adsorption and superoxide (O₂•⁻) generation, and the S-scheme heterojunction effectively suppresses electron–hole recombination while preserving strong redox potential. NT/C–AAP achieved 96% TCH degradation within 1 h and 82% mineralization in 3 h under solar light, far exceeding core–shell (18%) and aggregated (47%) NiTiO₃-based catalysts. Complete removal was realized within 40 min under 400 W visible light. The catalyst maintained 96% activity after five cycles, confirming excellent durability. Compared with previously reported NiTiO₃ photocatalysts, NT/C–AAP delivered a 50–400% performance enhancement arising from its engineered hollow structure and improved electronic properties. Mechanistic studies identified O₂•⁻ and •OH radicals as dominant species, validating the role of morphology and interface engineering in directing charge separation and redox activity. Additionally, a catalyst performance index was proposed to facilitate comparison across diverse conditions. Overall, this work introduces a novel, durable photocatalyst that links structural design to functional performance and demonstrates strong potential for practical environmental remediation.
KW - Heterojunction photocatalyst
KW - Photodegradation
KW - Tetracycline
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655946
DO - https://doi.org/10.1007/s42114-025-01600-x
SN - 2522-0128
VL - 9
IS - 2
SP - 1
EP - 19
PB - Springer Nature
CY - London
AN - OPUS4-65594
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Tuma, Dirk
A1 - Moreau, A.
A1 - Polishuk, I.
A1 - Segovia, J. J.
A1 - Vega-Maza, D.
A1 - Martín, M. C.
T1 - Measurements and predictions of densities and viscosities in CO2 + hydrocarbon mixtures at high pressures and temperatures: CO2 + n-pentane and CO2 + n-hexane blends
N2 - This work reports new experimental data on densities and viscosities of (CO2 + n-pentane) and (CO2 + n-hexane) mixtures at high pressures and temperatures. The densities were measured by a vibrating-tube densimeter with an expanded uncertainty (k = 2) smaller than 1.8 kg/m3 at six isotherms (from 273.15 K to 373.15 K), twelve pressures starting at 5 MPa up to 100 MPa, and at six CO2 molar compositions (from 0 to 0.6). The viscosities were measured by a vibrating-wire viscometer with the corresponding relative expanded uncertainty (k = 2) smaller than 0.016 at five isotherms (from 273.15 K to 373.15 K), twelve pressures (from 5 MPa up to 100 MPa), and at two CO2 molar compositions (0.1 and 0.3). The densities were fitted by the semiempirical Tammann-Tait equation for density data and the Vogel-Fulcher-Tammann (VFT) equation for viscosity data, respectively. The Groupe Européen de Recherches Gazières (GERG-2008) equation of state was also applied for modelling the densities. Over-all robustness and reliability of the Perturbed-Chain Statistical Association Fluid Theory (PC-SAFT) and its critical point-based modification (CP-PC-SAFT) were examined. Accuracies of the Modified Yarranton-Satyro (MYS) coupled with CP-PC-SAFT and the NIST Reference Fluid Thermodynamic and Transport Properties Database (REFPROP 10) in predicting the viscosities were evaluated.
KW - CO2 + n-alkanes
KW - thermophysical properties
KW - Perturbed-Chain Statistical Association Fluid Theory
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-555728
DO - https://doi.org/10.1016/j.molliq.2022.119518
SN - 0167-7322
VL - 360
SP - 1
EP - 15
PB - Elsevier
CY - Amsterdam
AN - OPUS4-55572
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Valderrey, Virginia
A1 - Gawlitza, Kornelia
A1 - Rurack, Knut
T1 - Thiourea- and Amino-Substituted Benzoxadiazole Dyes with Large Stokes Shifts as Red-Emitting Probe Monomers for Imprinted Polymer Layers Targeting Carboxylate-Containing Antibiotics
N2 - Bifunctional fluorescent molecular oxoanion probes based on the benzoxadiazole (BD) chromophore are described which integrate a thiourea binding motif and a polymerizable 2-aminoethyl methacrylate unit in the 4,7-positions of the BD core. Concerted charge transfer in this electron donor-acceptor-donor architecture endows the dyes with strongly Stokes shifted (up to >250 nm) absorption and fluorescence. Binding of electron-rich carboxylate guests at the thiourea receptor leads to further analyte-induced red-shifts of the emission, shifting the fluorescence maximum of the complexes to ≥700 nm. Association constants for acetate are ranging from 1–5×105 M−1 in acetonitrile. Integration of one of the fluorescent probes through its polymerizable moiety into molecularly imprinted polymers (MIPs) grafted from the surface of submicron silica cores yielded fluorescent MIP-coated particle probes for the selective detection of antibiotics containing aliphatic carboxylate groups such as enoxacin (ENOX) at micromolar concentrations in highly polar solvents like acetonitrile.
KW - Molecular imprinting
KW - Anion recognition
KW - Antibiotics
KW - Benzoxadiazole dyes
KW - Charge transfer
KW - Fluorescence
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-545027
DO - https://doi.org/10.1002/chem.202104525
SN - 1521-3765
SP - 1
EP - 9
PB - Wiley-VCH
AN - OPUS4-54502
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Veico, V. P.
A1 - Karlagina, Yu. Yu.
A1 - Samokhvalov, A. A.
A1 - Polyakov, D. S.
A1 - Manokhin, S. S.
A1 - Radaev, M. M.
A1 - Odintsova, G. V.
A1 - Gornushkin, Igor B.
T1 - Surface Structuring and Reverse Deposition of Nanoporous Titanium Oxides by Laser Ablation of Titanium in Air
N2 - The deposition of titanium oxides during titanium laser ablation in air has been experimentally and numerically investigated. A titanium sample was irradiated by nanosecond pulses from an Yb-fber laser with a beam scanned across the sample surface for its texturing. As a result, the hierarchical structure was observed consisting of a microrelief formed by the laser ablation and a nanoporous coating formed by the reverse deposition from the laser induced plasma plume. The chemical and phase composition of the nanoporous coating, as well as the morphology and structure of the surface, were studied using scanning electron microscopy, atomic force microscopy, and X-ray microanalysis. It was found that the deposit consists mostly of porous TiO2 with 26% porosity and inclusions of TiO, Ti2O3, and Ti2O3N. Optical emission spectroscopy was used to control the plasma composition and estimate the effective temperature of plasma plume. The chemical-hydrodynamic model of laser induced plasma was developed to get a deeper insight into the deposition process. The model predicts that condensed titanium oxides, formed in peripheral plasma
zones, gradually accumulate on the surface during the plasma plume evolution. A satisfactory agreement between the experimental and calculated chemical composition of the plasma plume as well as between the experimental and calculated composition and thickness of the deposited film was demonstrated. This allows a cautious conclusion that the formation of condensed oxides in the plasma and their consequent deposition onto the ablation surface are among the key mechanisms of formation of porous surface films.
KW - Laser ablation
KW - Laser induced plasma deposition
KW - Surface coating
KW - Titanium dioxide
KW - Hydrodynamic model
KW - Plasma chemistry
KW - Emission spectroscopy
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-548555
DO - https://doi.org/10.1007/s11090-022-10256-0
VL - 42
IS - 4
SP - 923
EP - 937
PB - Springer
AN - OPUS4-54855
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Verhassel, Alejandra
A1 - Kimani, Martha Wamaitha
A1 - Gidwani, Kamlesh
A1 - Sandholm, Jouko
A1 - Gawlitza, Kornelia
A1 - Rurack, Knut
A1 - Härkönen, Pirkko
T1 - Detection of Tn-antigen in breast and prostate cancer models by VVL-labeled red dye-doped nanoparticles
N2 - Aim: Fluorescence detection of breast and prostate cancer cells expressing Tn-antigen, a tumor marker, with Vicia villosa lectin (VVL)-labeled nanoparticles.
Materials & methods: Breast and prostate cancer cells engineered to express high levels of Tn-antigen and non-engineered controls were incubated with VVL-labeled or unlabeled red dye-doped silica-coated polystyrene nanoparticles. The binding to cells was studied with flow cytometry, confocal microscopy, and electron microscopy.
Results: Flow cytometry showed that the binding of VVL-labeled nanoparticles was significantly higher to Tn-antigen-expressing cancer cells than controls. Confocal microscopy demonstrated that particles bound to the cell surface. According to the correlative light and electron microscopy the particles bound mostly as aggregates.
Conclusion: VVL-labeled nanoparticles could provide a new tool for the detection of Tn-antigen-expressing breast and prostate cancer cells.
KW - Breast cancer cells
KW - Fluorescence detection
KW - Lectin labeling
KW - Prostate cancer cells
KW - Silica-coated polystyrene nanoparticles
KW - Tn-antigen
KW - VVL
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-613451
DO - https://doi.org/10.1080/17435889.2024.2405454
SN - 1743-5889
VL - 19
SP - 2463
EP - 2478
PB - Taylor & Francis
CY - London
AN - OPUS4-61345
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Vermeeren, Sarah
A1 - Witzler, Markus
A1 - Makarow, Ramona
A1 - Engelhard, Carsten
A1 - Kaul, Peter
T1 - Multivariate evaluation method for the detection of pest infestations on plants via VOC analysis using gas chromatography mass spectrometry
N2 - Volatile organic compounds (VOCs) play an important role in the defense against pest infestations on plants. The analysis of these VOCs using gas chromatography mass spectrometry (GC-MS) enables the detection of pests by analyzing the VOC composition (VOC profiles) for specific patterns and markers. The analysis of such complex datasets with high biovariability poses a particular challenge. For this reason, a multivariate evaluation method based on a self-written Python script, using principal component analysis (PCA) and linear discriminant analysis (LDA), was developed and tested for functionality using a dataset, which has been evaluated manually and has identified five specific markers (2,4-dimethyl-1-heptene, 3-carene, alpha-longipinene, cyclosativene, and copaene) for Anoplophora glabripennis (ALB) infestation on Acer trees. The results obtained in the present study did not only match the manually evaluated results, but lead to further insight into the dataset. Another sesquiterpene which is assumed to be alpha-zingiberene was identified as an ALB specific marker in addition to 2,4-dimethyl-1-heptene and 3-carene. Furthermore, the European native beetle species goat moth Cossus cossus (CC) and poplar long-horned beetle Saperda carcharias (SC) were also analyzed for their VOCs to differentiate ALB specific VOC from other pest infestations. This comparison lead to the conclusion that the compounds alpha-longipinene, cyclosativene, and copaene are not specific for ALB but for pest infestation in general. It was possible to identify not only specifically produced VOCs, but also differences in concentrations that arise specifically during ALB infestation. Therefore, the evaluation method for the detection of plant pests presented in this study represents a time-saving alternative to conventional non computing methods, which in addition provides more detailed results.
KW - Mass Spectrometry
KW - Gas Chromatography
KW - Volatile organic compounds
KW - Pest infestation
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-639526
DO - https://doi.org/10.1038/s41598-025-11607-5
SN - 2045-2322
VL - 15
IS - 1
SP - 1
EP - 10
PB - Springer Science and Business Media LLC
AN - OPUS4-63952
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Villajos Collado, José Antonio
T1 - Experimental volumetric hydrogen uptake determination at 77 K of commercially available metal-organic framework materials
N2 - Storage is still limiting the implementation of hydrogen as an energy carrier to integrate the intermittent operation of renewable energy sources. Among different solutions to the currently used compressed or liquified hydrogen systems, physical adsorption at cryogenic temperature in porous materials is an attractive alternative due to its fast and reversible operation and the resulting reduction in storage pressure. The feasibility of cryoadsorption for hydrogen storage depends mainly on the performance of the used materials for the specific application, where metal-organic frameworks or MOFs are remarkable candidates. In this work, gravimetric and volumetric hydrogen uptakes at 77 K and up to 100 bar of commercially available MOFs were measured since these materials are made from relatively cheap and accessible building blocks. These materials also show relatively high porous properties and are currently near to large-scale production. The measuring device was calibrated at different room temperatures to calculate an average correction factor and standard deviation so that the correction deviation is included in the measurement error for better comparability with different measurements. The influence of measurement conditions was also studied, concluding that the available adsorbing area of material and the occupied volume of the sample are the most critical factors for a reproducible measurement, apart from the samples’ preparation before measurement. Finally, the actual volumetric storage density of the used powders was calculated by directly measuring their volume in the analysis cell, comparing that value with the maximum volumetric uptake considering the measured density of crystals. From this selection of commercial MOFs, the materials HKUST-1, PCN-250(Fe), MOF-177, and MOF-5 show true potential to fulfill a volumetric requirement of 40 g·L−1 on a material basis for hydrogen storage systems without further packing of the powders.
KW - Hydrogen adsorption
KW - Commercial metal-organic frameworks
KW - Hydrogen uptake reproducibility
KW - Volumetric uptake
KW - Packing density
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-542215
DO - https://doi.org/10.3390/c8010005
SN - 2311-5629
VL - 8
IS - 1
SP - 1
EP - 14
PB - MDPI
CY - Basel
AN - OPUS4-54221
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Villajos Collado, José Antonio
A1 - Balderas‐Xicohténcatl, Rafael
A1 - Al Shakhs, Ali N.
A1 - Berenguer‐Murcia, Ángel
A1 - Buckley, Craig E.
A1 - Cazorla‐Amorós, Diego
A1 - Charalambopoulou, Georgia
A1 - Couturas, Fabrice
A1 - Cuevas, Fermin
A1 - Fairen‐Jimenez, David
A1 - Heinselman, Karen N.
A1 - Humphries, Terry D.
A1 - Kaskel, Stefan
A1 - Kim, Hyunlim
A1 - Marco‐Lozar, Juan P.
A1 - Oh, Hyunchul
A1 - Parilla, Philip A.
A1 - Paskevicius, Mark
A1 - Senkovska, Irena
A1 - Shulda, Sarah
A1 - Silvestre‐Albero, Joaquin
A1 - Steriotis, Theodore
A1 - Tampaxis, Christos
A1 - Hirscher, Michael
A1 - Maiwald, Michael
T1 - Establishing ZIF‐8 as a reference material for hydrogen cryoadsorption: An interlaboratory study
N2 - AbstractHydrogen storage by cryoadsorption on porous materials has the advantages of low material cost, safety, fast kinetics, and high cyclic stability. The further development of this technology requires reliable data on the H2 uptake of the adsorbents, however, even for activated carbons the values between different laboratories show sometimes large discrepancies. So far no reference material for hydrogen cryoadsorption is available. The metal‐organic framework ZIF‐8 is an ideal material possessing high thermal, chemical, and mechanical stability that reduces degradation during handling and activation. Here, we distributed ZIF‐8 pellets synthesized by extrusion to 9 laboratories equipped with 15 different experimental setups including gravimetric and volumetric analyzers. The gravimetric H2 uptake of the pellets was measured at 77 K and up to 100 bar showing a high reproducibility between the different laboratories, with a small relative standard deviation of 3–4 % between pressures of 10–100 bar. The effect of operating variables like the amount of sample or analysis temperature was evaluated, remarking the calibration of devices and other correction procedures as the most significant deviation sources. Overall, the reproducible hydrogen cryoadsorption measurements indicate the robustness of the ZIF‐8 pellets, which we want to propose as a reference material.
KW - Physical and theoretical chemistry
KW - Atomic and molecular physics, and optics
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-594788
DO - https://doi.org/10.1002/cphc.202300794
SN - 1439-7641
SP - 1
EP - 7
PB - Wiley
CY - Weinheim
AN - OPUS4-59478
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Villajos Collado, José Antonio
A1 - Bienert, M.
A1 - Gugin, Nikita
A1 - Emmerling, Franziska
A1 - Maiwald, Michael
T1 - A database to select affordable MOFs for volumetric hydrogen cryoadsorption considering the cost of their linkers
N2 - Physical adsorption at cryogenic temperature (cryoadsorption) is a reversible mechanism that can reduce the pressure of conventional compressed gas storage systems. Metal–organic framework (MOF) materials are remarkable candidates due to the combination of high specific surface area and density which, in some cases, provide a high volumetric storage capacity. However, such extensive use of MOFs for this application requires the selection of affordable structures, easy to produce and made from feasible metallic and organic components. Herein, we introduce a MOF database detailing the crystallographic and porous properties of 3600 existing MOFs made from industrially relevant metals and their organic composition. The comparison of the available minimum costs of linkers allowed the creation of a database to select affordable structures with high potential for volumetric hydrogen storage by cryoadsorption, considering their composition based on individual or mixed building blocks. A user inter� face, available online, facilitates the selection of MOFs based on the properties or names of structures and linkers.
KW - MOF´s
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-583619
DO - https://doi.org/10.1039/d3ma00315a
VL - 4
IS - 18
SP - 4226
EP - 4237
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-58361
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Vogel, Christian
A1 - Roesch, Philipp
A1 - Wittwer, Philipp
A1 - Piechotta, Christian
A1 - Lisec, Jan
A1 - Sommerfeld, Thomas
A1 - Kluge, Stephanie
A1 - Herzel, Hannes
A1 - Huthwelker, T.
A1 - Borca, C.
A1 - Simon, Franz-Georg
T1 - Levels of per- and polyfluoroalkyl substances (PFAS) in various wastewater-derived fertilizers - Analytical investigations from different perspectives
N2 - Solid wastewater-based fertilizers were screened for per- and polyfluoroalkyl substances (PFAS) by the extractable organic fluorine (EOF) sum parameter method. The EOF values for ten sewage sludges from Germany and Switzerland range from 154 to 7209 mg kg−1. For thermal treated sewage sludge and struvite the EOF were lower with values up to 121 mg kg−1. Moreover, the application of PFAS targeted
and suspect screening analysis of selected sewage sludge samples showed that only a small part of the EOF sum parameter values can be explained by the usually screened legacy PFAS. The hitherto unknown part of EOF sum parameter contains also fluorinated pesticides, pharmaceutical and aromatic compounds. Because these partly fluorinated compounds can degrade to (ultra-)short PFAS in wastewater treatment plants they should be considered as significant sources of organic fluorine in the environment. The combined results of sum parameter analysis and suspect screening reveal the need to update current regulations, such as the German fertilizer ordinance, to focus not solely on a few selected PFAS such as perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) but
consider an additional sum parameter approach as a more holistic alternative. Moreover, diffusion gradient in thin-films (DGT) passive samplers were utilized as an alternative simplified extraction method for PFAS in solid wastewater-based fertilizers and subsequently quantified via combustion ion chromatography. However, the DGT method was less sensitive and only comparable to the EOF values
of the fertilizers in samples with >150 mg kg−1, because of different diffusion properties for various PFAS, but also kinetic exchange limitations.
KW - Combustion ion chromatography
KW - Per- and polyfluoroalkyl substances (PFAS)
KW - Sewage sludge
KW - Fertilizer
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-583429
DO - https://doi.org/10.1039/d3va00178d
SN - 2754-7000
VL - 2
IS - 10
SP - 1436
EP - 1445
PB - Royal Society of Chemistry (RSC)
CY - London
AN - OPUS4-58342
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Vogel, Christian
A1 - Roesch, Philipp
A1 - Wittwer, Philipp
A1 - Sommerfeld, Thomas
A1 - Riedel, Maren
A1 - Leube, Peter
A1 - Kalbe, Ute
A1 - Schoknecht, Ute
A1 - Simon, Franz-Georg
T1 - Per- and Polyfluoroalkyl Substances (PFAS) in Ski Waxes and Snow from Cross-Country Skiing in Germany - Comparative study of Sum Parameter and Target Analysis
N2 - Per- and polyfluoroalkyl substances (PFAS) are often environmentally exposed via discharge through human consumer products, such as ski waxes. In our study we analyzed various ski waxes from the 1980s and 2020s, to determine both the sum parameter values total fluorine (TF), extractable organically bound fluorine (EOF), hydrolysable organically bound fluorine (HOF) as well as targeted PFAS analysis. This showed that modern high-performance waxes contain up to 6 % TF, but also PFAS-free labelled ski waxes contain traces of PFAS with EOF/HOF values in the low mg kg-1 range. With the ban of all fluorine-based waxes with the start of the 2023/2024 winter season this will probably change soon. Moreover, we applied our analysis methods to snow samples from a frequently used cross country ski trail (Kammloipe) in the Ore Mountain region in Germany, assessing the potential PFAS entry/discharge through ski waxes. Melted snow samples from different spots were analyzed by the adsorbable organically bound fluorine (AOF) sum parameter and PFAS target analysis and confirmed the abrasion of the ski waxes into the snow. Moreover, on a PFAS hotspot also soil samples were analyzed, which indicate that PFAS from the ski waxes adsorb after snow melting into the soil.
KW - Combustion Ion Chromatography
KW - Per- and Polyfluoroalkyl substances (PFAS)
KW - Consumer Products
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-612760
DO - https://doi.org/10.1016/j.hazadv.2024.100484
VL - 16
SP - 1
EP - 5
PB - Elsevier B.V.
AN - OPUS4-61276
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Vogl, Jochen
T1 - The triple-isotope calibration approach: a universal and standard-free calibration approach for obtaining absolute isotope ratios of multi-isotopic elements
N2 - The theory of a new calibration approach for obtaining absolute isotope ratios of multi-isotopic elements without the use of any standard has been developed. The calibration approach basically uses the difference in the instrumental isotope fractionation of two different types of mass spectrometers, leading to two different fractionation lines in a three-isotope diagram. When measuring the same sample with both mass spectrometers, the different fractionation lines have one point in common: this is the ‘true’ logarithmized isotope ratio pair of the sample. Thus, the intersection of both fractionation lines provides us with the absolute isotope ratios of the sample. This theory has been tested in practice by measuring Cd and of Pb isotope ratios in the certified reference materials BAM-I012 and NIST SRM981 by thermal ionization mass spectrometry and by inductively coupled plasma mass spectrometry while varying the ionization conditions for both mass spectrometers. With this experiment, the theory could be verified, and absolute isotope ratios were obtained, which were metrologically compatible with the certified isotope ratios. The so-obtained absolute isotope ratios are biased by − 0.5% in average, which should be improved with further developments of the method. This calibration approach is universal, as it can be applied to all elements with three or more isotopes and it is not limited to the type of mass spectrometers applied; it can be applied as well to secondary ion mass spectrometry or others. Additionally, this approach provides information on the fractionation process itself via the triple-isotope fractionation exponent θ.
KW - Triple isotope fractionation
KW - Absolute isotope ratio
KW - Mass spectrometry
KW - Calibration
KW - Uncertainty
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-516364
DO - https://doi.org/10.1007/s00216-020-03050-4
VL - 413
IS - 3
SP - 821
EP - 826
PB - Springer Verlag
AN - OPUS4-51636
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Vogl, Jochen
A1 - Rienitz, O.
A1 - Pramann, A.
A1 - Flierl, L.
T1 - Scale Conversion and Uncertainty Calculations in Isotope Delta Measurements
N2 - Isotope ratio applications are on the increase and a major part of which are delta measurements, because they are easier to perform than the determination of absolute isotope ratios while offering lower measurement uncertainties. Delta measurements use artefact-based scales and therefore scale conversions are required due to the lack of the scale defining standards. Such scale conversions often form the basis for comparing data being generated in numerous projects andtherefore need to be as accurate as possible. In practice, users are tempted to apply linear approximations, which are not sufficiently exact, because delta values are defined by nonlinear relationships. The bias of such approximations often is beyond typical measurement uncertainties and its extent can hardly be predicted. Therefore, exact calculations are advised. Here, the exact equations and the bias of the approximations are presented, and calculations are illustrated by real-world examples. Measurement uncertainty is indispensable in this context and therefore, its calculation is described as well for determining delta values but also for scale conversions. Approaches for obtaining a single delta measurement and for repeated measurements are presented. For the latter case, a new approach for calculating the measurement uncertainty is presented, which considers covariances between the isotope ratios.
KW - Delta isotope standard
KW - Delta scale
KW - In-house calibration solution
KW - Isotope ratios
KW - Isotope reference material
KW - Measurement uncertainty
KW - Scale conversion
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-557254
DO - https://doi.org/10.1111/ggr.12450
SN - 1639-4488
VL - 46
IS - 4
SP - 773
EP - 787
PB - Wiley
AN - OPUS4-55725
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Vogl, Jochen
A1 - Rosner, M.
A1 - Kasemann, S. A.
A1 - Kraft, R.
A1 - Meixner, A.
A1 - Noordmann, J.
A1 - Rabb, S.
A1 - Rienitz, O.
A1 - Schuessler, J. A.
A1 - Tatzel, Michael
A1 - Vocke, R. D.
T1 - Intercalibration of Mg isotope delta scales and realisation of SI traceability for Mg isotope amount ratios and isotope delta values
N2 - The continuous improvement of analytical procedures using multi-collector technologies in ICP-mass spectrometry has led to an increased demand for isotope standards with improved homogeneity and reduced measurement uncertainty. For magnesium, this has led to a variety of available standards with different quality levels ranging from artefact standards to isotope reference materials certified for absolute isotope ratios. This required an intercalibration of all standards and reference materials, which we present in this interlaboratory comparison study. The materials Cambridge1, DSM3, ERMAE143, ERM-AE144, ERM-AE145, IRMM-009 and NIST SRM 980 were cross-calibrated with expanded measurement uncertainties (95% confidence level) of less than 0.030‰ for the δ25/24Mg values and less than 0.037‰ for the δ26/24Mg values. Thus, comparability of all magnesium isotope delta (δ) measurements based on these standards and reference materials is established. Further, ERM-AE143 anchors all magnesium δ-scales to absolute isotope ratios and therefore establishes SI traceability, here traceability to the SI base unit mole. This applies especially to the DSM3 scale, which is proposed to be maintained. With ERM-AE144 and ERM-AE145, which are product and educt of a sublimation-condensation process, for the first time a set of isotope reference materials is available with a published value for the apparent triple isotope fractionation exponent θapp, the fractionation relationship ln α(25/24Mg)/ln α(26/24Mg).
KW - Delta scale
KW - Traceability
KW - Scale anchor
KW - Absolute isotope ratio
KW - Comparability
KW - Triple isotope fractionation
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-511557
DO - https://doi.org/10.1111/ggr.12327
SN - 1751-908X
VL - 44
IS - 3
SP - 439
EP - 457
PB - Wiley-Blackwell
CY - Oxford
AN - OPUS4-51155
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - von Boehn, B.
A1 - Scholtz, Lena
A1 - Imbihl, R.
T1 - Reactivity and Stability of Ultrathin VOx Films on Pt(111) in Catalytic Methanol Oxidation
N2 - The growth of ultrathin layers of VOx (<12 monolayers) on Pt(111) and the activity of these layers in catalytic methanol oxidation at 10−4 mbar have been studied with low-energy electron difraction, Auger electron spectroscopy, rate measurements, and with photoemission electron microscopy. Reactive deposition of V in O2 at 670 K obeys a Stranski–Krastanov growth mode with a (√3 × √3)R30° structure representing the limiting case for epitaxial growth of 3D-VOx. The activity of VOx/Pt(111) in catalytic methanol oxidation is very low and no redistribution dynamics is observed lifting the initial spatial homogeneity of the VOx layer. Under reaction conditions, part of the surface vanadium difuses into the Pt subsurface region.
Exposure to O2 causes part of the V to difuse back to the surface, but only up to one monolayer of VOx can be stabilized in this way at 10−4 mbar.
KW - Vanadium oxide catalysts
KW - Pt(111)
KW - Supported catalyst
KW - Methanol oxidation
KW - Stranski–Krastanow growth
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-517376
DO - https://doi.org/10.1007/s11244-020-01321-z
SN - 1022-5528
VL - 63
IS - 15-18
SP - 1545
EP - 1556
PB - Springer
AN - OPUS4-51737
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - von der Au, Marcus
A1 - Faßbender, Sebastian
A1 - Chronakis, Michail
A1 - Vogl, Jochen
A1 - Meermann, Björn
T1 - Size determination of nanoparticles by ICP-ToF-MS using isotope dilution in microdroplets
N2 - Within this work, the combination of a microdroplet generator and an ICP-ToF-MS for nanoparticle analysis is presented. For the size determination of platinum nanoparticles an on-line isotope dilution analysis approach was developed. The 194Pt/195Pt isotopic ratio was used for the characterization of the particles, while the 182W/183W isotopic ratio was monitored simultaneously for mass bias correction. The on-line ID-MDG-sp-ICP-ToF-MS approach was deployed for the size determination of three platinum nanoparticle samples (50 nm, 63 nm, 70 nm); for validation, complementary size characterization techniques (sp-ICP-ToF-MS and TEM) were used. The robustness of this technique was evidenced, by using sodium chloride concentrations up to 100 mg L−1 as a matrix component. Our new on-line ID MDG-sp-ICP-ToF-MS approach is a promising tool for the fast and reliable determination of nanoparticles' size in severe matrix concentrations, e.g., environmental samples.
KW - ICP-ToF-MS
KW - Nanoparticles
KW - Isotope Dilution
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-552727
DO - https://doi.org/10.1039/D2JA00072E
SN - 0267-9477
VL - 37
IS - 6
SP - 1203
EP - 1207
PB - Royal Society of Chemistry
AN - OPUS4-55272
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - von Törne, Wipert Jannik
A1 - Klyk-Seitz, Urszula-Anna
A1 - Piechotta, Christian
T1 - Developing a GC-EI-MS/MS method for quantifying warfarin and five hydroxylated metabolites generated by the Fenton reaction
N2 - AbstractSince the 1950s, Warfarin has been used globally as both a prescription drug and a rodenticide. Research has shown that warfarin and other rodenticides are present in the environment and food chain. However, emerging contaminants are subject to degradation by biotic and abiotic processes and advanced oxidation processes. In some cases, detecting the parent compound may not be possible due to the formation of structurally changed species. This approach aims to identify hydroxylated transformation products of warfarin in a laboratory setting, even after the parent compound has undergone degradation. Therefore, the Fenton reaction is utilized to insert hydroxylation into the parent compound, warfarin, by hydroxyl and hydroperoxyl radicals generated by Fe2+/Fe3+ redox reaction with hydrogen peroxide. Using multiple reaction monitoring, a GC–MS/MS method, incorporating isotopically labeled reference compounds, is used to quantify the expected derivatized species. The analytes are derivatized using trimethyl-3-trifluoromethyl phenyl ammonium hydroxide, and the derivatization yield of warfarin is determined by using isotopically labeled reference compounds. The method has a linear working range of 30 to 1800 ng/mL, with detection limits ranging from 18.7 to 67.0 ng/mL. The analytes are enriched using a C18-SPE step, and the recovery for each compound is calculated. The Fenton reaction generates all preselected hydroxylated transformation products of warfarin. The method successfully identifies that 4′-Me-O-WAR forms preferentially under the specified experimental conditions. By further optimizing the SPE clean-up procedures, this GC–MS-based method will be suitable for detecting transformation products in more complex matrices, such as environmental water samples. Overall, this study provides a better understanding of warfarin’s degradation and offers a robust analytical tool for investigating its transformation products.
KW - Health, Toxicology and Mutagenesis
KW - Pollution
KW - Environmental Chemistry
KW - General Medicine
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-595737
DO - https://doi.org/10.1007/s11356-024-32133-3
SN - 0944-1344
VL - 31
SP - 16986
EP - 16994
PB - Springer Science and Business Media LLC
AN - OPUS4-59573
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - von Törne, Wipert Jannik
A1 - Steinhäuser, Lorin
A1 - Klyk-Seitz, Urszula-Anna
A1 - Piechotta, Christian
T1 - High-resolution mass spectrometric elucidation of electron ionization induced fragmentation pathways of methylated warfarin and selected hydroxylated species
N2 - The plant secondary metabolite families of coumarin and 4-hydroxy coumarin have a broad pharmacological spectrum ranging from antibacterial to anticancer properties. One prominent member of this substance class is the synthetic but naturally inspired anticoagulant drug and rodenticide warfarin (coumadin). A vast number of publications focus on the identification of warfarin and its major cytochrome P450-mediated phase I metabolites by liquid chromatography (LC) with mass spectrometry (MS) and tandem mass spectrometric (MS/MS) detection techniques. For the first time, electron ionization (EI) induced high-resolution quadrupole time-of-flight mass spectrometric (HR-qToF-MS) data of in-liner derivatized warfarin and selected hydroxylated species is provided in this study as an alternative to LC-MS/MS approaches. Furthermore, the characteristic fragments and fragmentation pathways of the analyzed methyl ethers are concluded. The obtained data of analytical standards, specific deuterated and 13C-labeled compounds prove inductive cleavage of the acyl or acetonyl side chain, methyl migration, and H-migration, along with consequential inductive cleavage as predominant fragmentation routes. Based on the HR-spectral data, commonalities and differences between the analyzed compounds and fragment groups were evaluated with future applicability in structure elucidation and spectra prediction of related compounds.
KW - High-resolution mass spectrometry
KW - Warfarin
KW - Hydroxy warfarin
KW - Fragmentation pathway
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-596025
DO - https://doi.org/10.1016/j.ijms.2024.117220
SN - 1387-3806
VL - 499
SP - 1
EP - 7
PB - Elsevier B.V.
AN - OPUS4-59602
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Völker, Tobias
A1 - Gornushkin, Igor B.
T1 - Importance of physical units in the Boltzmann plot method
N2 - The Boltzmann plot is one of the most widely used methods for determining the temperature in different types of laboratory plasmas. It operates on the logarithm as a function of the dimensional argument, which assumes that the correct physical units are used. In many works using the Boltzmann method, there is no analysis of the dimension of this argument, which may be the cause of a potential error. This technical note offers a brief description of the method and shows how to correctly use physical units when using transcendental functions like the logarithm.
KW - Boltzmann plot
KW - Laser induced plasma
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-558039
DO - https://doi.org/10.1039/d2ja00241h
SP - 1
EP - 3
PB - Royal Society of Chemistry
AN - OPUS4-55803
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Völker, Tobias
A1 - Gornushkin, Igor B.
T1 - Investigation of a method for the correction of self-absorption by Planck function in laser induced breakdown spectroscopy
N2 - The electron density and temperature of a laser-induced plasma can be determined from the width and intensity of the spectral lines, provided that the corresponding optical transitions are optically thin. However, the lines in laser induced plasma are often self-absorbed. One of the methods of correction of this effect is based on the use of the Planck function and an iterative numerical calculation of the plasma temperature. In this study, the method is further explored and its inherent errors and limitations are evaluated. For this, synthetic spectra are used that fully correspond to the assumed conditions of a homogeneous isothermal plasma at local thermodynamic equilibrium. Based on the error analysis, the advantages and disadvantages of the method are discussed in comparison with other methods of self-absorption correction.
KW - LIBS
KW - Self-absorption
KW - Planck function
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-572677
DO - https://doi.org/10.1039/D2JA00352J
SN - 0267-9477
SP - 1
EP - 6
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-57267
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Völker, Tobias
A1 - Gornushkin, Igor B.
T1 - Mass and mole fractions in calibration-free LIBS
N2 - This technical note highlights the fact that CF-LIBS algorithms work in mole fractions, while results of spectrochemical analysis are usually reported in mass fractions or mass percent. Ignoring this difference and not converting mole fractions to mass fractions can lead to errors in reported concentrations determined by the CF-LIBS method and inadequate comparison of these concentrations with certified concentrations. Here, the key points of the CF-LIBS algorithm are reproduced and the formulae for converting a mole fraction to a mass fraction and vice versa are given. Several numerical examples are also given, which show that the greater the difference between the molar mass of an individual element in a sample and the average molar mass, the greater the discrepancy between the mole and mass fractions.
KW - Spectroscopy
KW - Analytical Chemistry
KW - LIBS
KW - Calibration
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-598611
DO - https://doi.org/10.1039/d4ja00028e
SN - 0267-9477
VL - 39
IS - 4
SP - 1030
EP - 1032
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-59861
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Völzke, Jule L.
A1 - Hodjat Shamami, Parya
A1 - Gawlitza, Kornelia
A1 - Feldmann, Ines
A1 - Zimathies, Annett
A1 - Meyer, Klas
A1 - Weller, Michael G.
T1 - High-purity corundum as support for affinity extractions from complex samples
N2 - Nonporous corundum powder, known as an abrasive material in the industry, was functionalized covalently with protein binders to isolate and enrich specific proteins from complex matrices. The materials based on corundum were characterized by TEM, ESEM, BET, DLS, EDS, and zeta potential measurements. The strong Al-O-P bonds between the corundum surface and amino phosphonic acids were used to introduce functional groups for further conjugations. The common crosslinker glutaraldehyde was compared with a hyperbranched polyglycerol (PG) of around 10 kDa. The latter was oxidized with periodate to generate aldehyde groups that can covalently react with the amines of the surface and the amino groups from the protein via a reductive amination process. The amount of bound protein was quantified via aromatic amino acid analysis (AAAA). This work shows that oxidized polyglycerol can be used as an alternative to glutaraldehyde. With polyglycerol, more of the model protein bovine serum albumin (BSA) could be attached to the surface under the same conditions, and lower non-specific binding (NSB) was observed. As a proof of concept, IgG was extracted with protein A from crude human plasma. The purity of the product was examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). A binding capacity of 1.8 mg IgG per gram of corundum powder was achieved. The advantages of corundum include the very low price, extremely high physical and chemical stability, pressure resistance, favorable binding kinetics, convenient handling, and flexible application.
KW - Corundum
KW - Sapphire
KW - Affinity chromatography
KW - Antibodies
KW - Self-assembled monolayers (SAM)
KW - Polyglycerol
KW - Dendrimer
KW - Nonspecific binding (NSB)
KW - Purification
KW - Solid-phase extraction (SPE)
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559342
DO - https://doi.org/10.3390/separations9090252
VL - 9
IS - 9
SP - 1
EP - 13
PB - MDPI
CY - Basel
AN - OPUS4-55934
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Völzke, Jule L.
A1 - Smatty, Sarah
A1 - Döring, Sarah
A1 - Ewald, Shireen
A1 - Oelze, Marcus
A1 - Fratzke, Franziska
A1 - Flemig, Sabine
A1 - Konthur, Zoltán
A1 - Weller, Michael G.
T1 - Efficient Purification of Polyhistidine-Tagged Recombinant Proteins Using Functionalized Corundum Particles
N2 - Immobilized metal affinity chromatography (IMAC) is a widely used technique for purifying polyhistidine-tagged recombinant proteins. However, it often has practical limitations that require complex optimizations and additional steps for purification. In this study, we introduce functionalized corundum particles as a novel, efficient, and economical method for purifying recombinant proteins in a column-free format. The corundum surface is modified with amino silane APTES, followed by EDTA dianhydride, and then loaded with nickel ions. We used the Kaiser test to monitor the modification process and ICP-MS to quantify the metal-binding capacity. To evaluate the system, we used His-tagged protein A/G (PAG) mixed with bovine serum albumin (BSA). The corundum particles exhibited a binding capacity of approximately 3 mg of protein per gram of corundum or 2.4 mg per 1 mL of corundum suspension. We also examined cytoplasm obtained from different E. coli strains as an example of a complex matrix. Varying the imidazole concentration in the loading and washing buffers showed that higher concentrations during loading improved purity. Even with sample volumes as large as one liter, we successfully isolated recombinant proteins down to a concentration of 1 µg/mL. We found higher purity levels with corundum when comparing the corundum material to standard Ni–NTA agarose beads. We successfully purified His6-MBP-mSA2, a fusion protein comprising monomeric streptavidin and maltose-binding protein, from E. coli cytoplasm, demonstrating the method's applicability. We also purified SARS-CoV-2-S-RBD-His8 expressed in human Expi293F cells, confirming its suitability for mammalian cell culture supernatants. The material cost of the nickel-loaded corundum material (without regeneration) is estimated to be less than 30 cents per gram of functionalized support or 10 cents per milligram of isolated protein. Another advantage of this system is the exceptional physical and chemical stability of corundum particles. Overall, we have demonstrated that this novel material offers an efficient, robust, and cost-effective purification platform for His-tagged proteins, even in challenging, complex matrices and large sample volumes with low product concentrations. This method has potential applications in both small laboratories and large-scale industrial settings.
N2 - Die immobilisierte Metallaffinitätschromatographie (IMAC) ist eine weit verbreitete Technik zur Reinigung von rekombinanten Proteinen mit Polyhistidin-Markierung. Sie hat jedoch oft praktische Einschränkungen, die komplexe Optimierungen und zusätzliche Schritte für die Aufreinigung erfordern. In dieser Studie stellen wir funktionalisierte Korundpartikel als neuartige, effiziente und wirtschaftliche Methode zur Reinigung rekombinanter Proteine in einem säulenfreien Format vor. Die Korundoberfläche wird mit dem Aminosilan APTES und anschließend mit EDTA-Dianhydrid modifiziert und dann mit Nickelionen beladen. Wir haben den Kaiser-Test zur Überwachung des Modifizierungsprozesses und ICP-MS zur Quantifizierung der Metallbindungskapazität verwendet. Zur Charakterisierung des Systems verwendeten wir His-markiertes Protein A/G (PAG) in Kombination mit Rinderserumalbumin (BSA). Die Korundpartikel wiesen eine Bindungskapazität von etwa 3 mg Protein pro Gramm Korund oder 2,4 mg pro 1 ml Korundsuspension auf. Als Beispiel für eine komplexe Matrix untersuchten wir auch Zytoplasma, das aus verschiedenen E. coli-Stämmen gewonnen wurde. Die Variation der Imidazolkonzentration in den Lade- und Waschpuffern zeigte, dass höhere Konzentrationen beim Laden die Reinheit verbesserten. Selbst bei einem Probenvolumen von bis zu einem Liter konnten wir rekombinante Proteine von 1 µg/mL isolieren. Beim Vergleich des Korundmaterials mit Standard-Ni-NTA-Agarose-Beads stellten wir einen höheren Reinheitsgrad mit Korund fest. Wir reinigten erfolgreich His6-MBP-mSA2 aus E. coli-Zytoplasma, ein Fusionsprotein, das aus monomerem Streptavidin und Maltose-bindendem Protein besteht. Wir reinigten auch SARS-CoV-2-S-RBD-His8, das in humanen Expi293F-Zellen exprimiert wurde, und bestätigten damit die Eignung des Materials für Zellkulturüberstände von Säugetieren. Die Materialkosten für nickelbeladenen Korund (ohne Regenerierung) werden auf weniger als 30 Cent pro Gramm funktionalisierten Trägers oder 10 Cent pro Milligramm isolierten Proteins geschätzt. Ein weiterer Vorteil dieses Systems ist die außergewöhnliche physikalische und chemische Stabilität der Korundpartikel. Insgesamt haben wir gezeigt, dass dieses neuartige Material eine effiziente, robuste und kostengünstige Reinigungsplattform für His-markierte Proteine bietet, selbst bei schwierigen, komplexen Matrices und großen Probenmengen mit niedrigen Produktkonzentrationen. Diese Methode könnte sowohl in kleinen Labors als auch in der Großindustrie eingesetzt werden.
KW - Aluminum oxide
KW - Sapphire
KW - Ethylenediaminetetraacetic acid
KW - Nickel chelate
KW - EDTAD
KW - HexaHis-Tag
KW - His6
KW - 6xHis
KW - His8
KW - Bioseparation
KW - IMAC purification
KW - Immunocapture
KW - Affinity chromatography
KW - Carrier
KW - Nickel
KW - Recombinant protein
KW - Escherichia coli
KW - Bacterial lysates
KW - Cytoplasm
KW - Polishing
KW - Downstream processing
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-575672
DO - https://doi.org/10.3390/biotech12020031
VL - 12
IS - 2
SP - 1
EP - 18
PB - MDPI
CY - Basel, Schweiz
AN - OPUS4-57567
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wander, Lukas
A1 - Lommel, Lukas
A1 - Braun, Ulrike
A1 - Meyer, Klas
A1 - Paul, Andrea
T1 - Development of a Low-Cost Method for Quantifying Microplastics in Soils and Compost Using Near-Infrared Spectroscopy
N2 - Near-infrared (NIR) spectroscopy is a promising candidate for low-cost, nondestructive, and highthroughput mass quantification of microplastics in environmental samples. Widespread application of the technique is currently hampered mainly by the low sensitivity of NIR spectroscopy compared to thermoanalytical approaches commonly used for this type of analysis. This study shows how the application of NIR spectroscopy for mass quantification of microplastics can be extended to smaller analyte levels by combining it with a simple and rapid microplastic enrichment protocol. For this purpose, the widely used flotation of microplastics in a NaCl solution, accelerated by centrifugation, was chosen which allowed to remove up to 99 % of the matrix at recovery rates of 83–104 %. The spectroscopic measurements took place directly on the stainless-steel filters used to collect the extracted particles to reduce sample handling to a minimum. Partial least squares regression (PLSR) models were used to identify and quantify the extracted microplastics in the mass range of 1–10 mg.
The simple and fast extraction procedure was systematically optimized to meet the requirements for the quantification of microplastics from common PE-, PP-, and PS-based packaging materials with a particle size < 1 mm found in compost or soils with high natural organic matter content (> 10 % determined by loss on ignition). Microplastics could be detected in model samples at a mass fraction of 1 mg g-1. The detectable microplastic mass fraction is about an order of magnitude lower compared to previous studies using NIR spectroscopy without additional enrichment. To emphasize the cost-effectiveness of the method, it was implemented using some of the cheapest and most
compact NIR spectrometers available.
KW - Mikroplastik
KW - NIR
KW - Sensor
KW - Kompost
KW - Multivariat
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-552605
DO - https://doi.org/10.1088/1361-6501/ac5e5f
VL - 33
IS - 7
SP - 1
EP - 13
PB - IOP Publishing Ltd.
CY - Bristol
AN - OPUS4-55260
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wander, Lukas
A1 - Lommel, Lukas
A1 - Meyer, Klas
A1 - Braun, Ulrike
A1 - Paul, Andrea
T1 - Development of a low-cost method for quantifying microplastics in soils and compost using near-infrared spectroscopy
N2 - Near-infrared (NIR) spectroscopy is a promising candidate for low-cost, nondestructive, and high-throughput mass quantification of micro¬plastics in environmental samples. Widespread application of the technique is currently hampered mainly by the low sensitivity of NIR spectroscopy compared to thermo-analytical approaches commonly used for this type of analysis. This study shows how the application of NIR spectroscopy for mass quantification of microplastics can be extended to smaller analyte levels by combining it with a simple and rapid microplastic enrichment protocol. For this purpose, the widely used flotation of microplastics in a NaCl solution, accelerated by centrifugation, was chosen which allowed to remove up to 99 % of the matrix at recovery rates of 83–104 %. The spectroscopic measurements took place directly on the stainless-steel filters used to collect the extracted particles to reduce sample handling to a minimum. Partial least squares regression (PLSR) models were used to identify and quantify the extracted microplastics in the mass range of 1–10 mg. The simple and fast extraction procedure was systematically optimized to meet the requirements for the quantification of microplastics from common PE-, PP-, and PS-based packaging materials with a particle size < 1 mm found in compost or soils with high natural organic matter content (> 10 % determined by loss on ignition). Microplastics could be detected in model samples at a mass fraction of 1 mg g-1. The detectable microplastic mass fraction is about an order of magnitude lower compared to previous studies using NIR spectroscopy without additional enrichment. To emphasize the cost-effectiveness of the method, it was implemented using some of the cheapest and most compact NIR spectrometers available.
KW - NIR
KW - Soil
KW - compost
KW - PLSR
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546405
DO - https://doi.org/10.1088/1361-6501/ac5e5f
SN - 0957-0233
VL - 33
IS - 7
SP - 075801
EP - 075814
PB - IOP Publishing Ltd.
CY - UK
AN - OPUS4-54640
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wang, Cui
A1 - Ebel, Kenny
A1 - Heinze, Katja
A1 - Resch-Genger, Ute
A1 - Bald, Ilko
T1 - Quantum Yield of DNA Strand Breaks under Photoexcitation of a Molecular Ruby
N2 - Photodynamic therapy (PDT) used for treating cancer relies on the generation of highly reactive oxygen species, for example, singlet oxygen 1O2, by light-induced excitation of a photosensitizer (PS) in the presence of molecular oxygen, inducing DNA damage in close proximity of the PS. Although many precious metal complexes have been explored as PS for PDT and received clinical approval, only recently, the potential of photoactive complexes of nonnoble metals as PS has been discovered. Using the DNA origami technology that can absolutely quantify DNA strand break cross sections, we assessed the potential of the luminescent transition metal complex [Cr(ddpd)2]3+ (ddpd=N,N’-dimethyl-N,N’-dipyridine-2-ylpyridine-2,6-diamine) to damage DNA in an air-saturated aqueous environment upon UV/Vis illumination. The quantum yield for strand breakage, that is, the ratio of DNA strand breaks to the number of absorbed photons, was determined to 1–4%, indicating efficient transformation of photons into DNA strand breaks by [Cr(ddpd)2]3+.
KW - Fluorescence
KW - Synthesis
KW - Production
KW - Optical spectroscopy
KW - Ligand
KW - Photophysics
KW - Cr(III)
KW - Mechanism
KW - NIR
KW - PDT
KW - Singlet oxygen
KW - DNA
KW - Origami
KW - Quantum yield
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-573631
DO - https://doi.org/10.1002/chem.202203719
SP - 1
EP - 7
AN - OPUS4-57363
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wang, Cui
A1 - Kitzmann, W.R.
A1 - Weigert, Florian
A1 - Förster, Ch.
A1 - Wang, X.
A1 - Heintze, K.
A1 - Resch-Genger, Ute
T1 - Matrix Effects on Photoluminescence and Oxygen Sensitivity of a Molecular Ruby
N2 - The molecular ruby analogue [Cr(ddpd)2]3+ (ddpd=N,N’-dimethyl-N,N’-dipyridine-2-ylpyridine-2,6-diamine) exhibits near infrared (NIR) emission with a high photoluminescence (PL) quantum yield ΦPL of 11 % and a lifetime of 898 μs in deaerated water at room temperature. While ligand-based control of the photophysical properties has received much attention, influences of the counter anions and microenvironment are still underexplored. In this study, the luminescence properties of the molecular ruby were systematically examined for the counter anions Cl−, Br−, [BF4]−, [PF6]−, [BPh4]−, and [BArF24]− in acetonitrile (MeCN) solution, in crystals, and embedded into polystyrene nanoparticles (PSNP). Stern-Volmer analyses of the oxygen quenching studies in the intensity and lifetime domain showed the highest oxygen sensitivity of the complexes with the counter anions of [BF4]− and [BArF24]−, which also revealed the longest luminescence lifetimes. Embedding [Cr(ddpd)2][PF6]3 in PSNPs and shielding with poly(vinyl alcohol) yields a strongly NIR-emissive oxygen-insensitive material with a record ΦPL of 15.2 % under ambient conditions.
KW - Fluorescence
KW - Sensor
KW - Oxygen
KW - Quantum yield
KW - Quality assurance
KW - Complex
KW - Cr(III)
KW - Lifetime
KW - Ligand
KW - Solid state
KW - X-Ray analysis
KW - Structure-property relationship
KW - Nano
KW - Polymer
KW - Particle
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546057
DO - https://doi.org/10.1002/cptc.202100296
SN - 2367-0932
VL - 6
IS - 6
SP - 1
EP - 9
PB - Wiley-VCH
CY - Weinheim
AN - OPUS4-54605
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wang, P.
A1 - Morales-Marquez, R.
A1 - Cervas, G.
A1 - Hernandez Medel, A.
A1 - Ogayar, M. P.
A1 - Jimenez de Aberasturi, D.
A1 - de Isidro-Gomez, A. I.
A1 - Torres-Padro, A.
A1 - Palomares, F. J.
A1 - Garcia-Orrit, S.
A1 - Sousa, C. T.
A1 - Espinosa, A.
A1 - Telle, H. H.
A1 - Ortgies, D. H.
A1 - Vega-Mayoral, V.
A1 - Cabanillas-Gonzalez, J.
A1 - Rodriguez, E. M.
A1 - Resch-Genger, Ute
A1 - Wegner, Karl David
A1 - Juarez, B. H.
T1 - The role of temperature in the photoluminescence quantum yield (PLQY) of Ag2S-based nanocrystals
N2 - Highly emissive Ag2S nanocrystals (NCs) passivated with a gradated shell incorporating Se and Zn were synthesized in air, and the temperature dependence of their photoluminescence quantum yield (PLQY) was quantified in both organic and aqueous media at B1200 nm. The relevance of this parameter, measured at physiological temperatures, is highlighted for applications that rely on the near infrared (NIR) photoluminescence of NCs, such as deep NIR imaging or luminescence nanothermometry. Hyperspectral NIR imaging shows that Ag2S-based NCs with a PLQY in organic media of about 10% are inefficient for
imaging at 40 8C through 20 mm thick tissue with low laser irradiation
power densities. In contrast, water-transferred Ag2S-based NCs with an
initial PLQY of 2% in water exhibit improved robustness against temperature changes, enabling improved imaging performance.
KW - Quantum dots
KW - Ag2S
KW - Fluorescence
KW - Nanomaterial design
KW - Advanced nanomaterials
KW - Shortwave infrared (SWIR)
KW - Temperature sensing
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-613877
DO - https://doi.org/10.1039/D4MH01016G
SP - 1
EP - 11
PB - Royal Society of Chemistry (RSC)
AN - OPUS4-61387
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wasternack, J.
A1 - Schröder, H. V.
A1 - Witte, J. F.
A1 - Ilisson, M.
A1 - Hupatz, H.
A1 - Hille, J. F.
A1 - Gaedke, M.
A1 - Valkonen, A. M.
A1 - Sobottka, S.
A1 - Krappe, A.
A1 - Schubert, M.
A1 - Paulus, B.
A1 - Rissanen, K.
A1 - Sarkar, B.
A1 - Eigler, S.
A1 - Resch-Genger, Ute
A1 - Schalley, C. A.
T1 - Switchable protection and exposure of a sensitive squaraine dye within a redox active rotaxane
N2 - In nature,molecular environments in proteins can sterically protect and stabilize reactive species such as organic radicals through non-covalent interactions.Here, wereport a near-infrared fluorescent rotaxane in which the stabilization of a chemically labile squaraine fluorophore by the coordination of a tetralactam macrocycle can be controlled chemically and electrochemically. The rotaxane can be switched between two co-conformations inwhich thewheel either stabilizes or exposes the fluorophore. Coordination by the wheel affects the squaraine’s stability across four redox states and renders the radical anion significantly more stable—by a factor of 6.7—than without protection by a mechanically bonded wheel. Furthermore, the fluorescence properties can be tuned by the redox reactions in a stepwise manner. Mechanically interlockedmolecules provide an excellent scaffold to stabilize and selectively expose reactive species in a co-conformational switching process controlled by external stimuli.
KW - Fluorescence
KW - Dye
KW - Sensor
KW - Quantum yield
KW - Spectroscopy
KW - Photophysics
KW - Synthesis
KW - Squaraine
KW - Switch
KW - Redox-active
KW - Rotaxane
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-614959
DO - https://doi.org/10.1038/s42004-024-01312-1
VL - 7
SP - 1
EP - 11
AN - OPUS4-61495
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Weber, A.
A1 - von Randow, M.
A1 - Voigt, A.-L.
A1 - von der Au, Marcus
A1 - Fischer, E.
A1 - Meermann, Björn
A1 - Wagner, M.
T1 - Ingestion and toxicity of microplastics in the freshwater gastropodLymnaea stagnalis: No microplastic-induced effects alone or incombination with copper
N2 - The interaction of microplastics with freshwater biota and their interaction with other stressors is still not very well understood. Therefore, we investigated the ingestion, excretion and toxicity of microplastics in the freshwater gastropod Lymnaea stagnalis.
MP ingestion was analyzed as tissues levels in L. stagnalis after 6–96 h of exposure to 5–90 μm spherical polystyrene (PS) microplastics. To understand the excretion, tissue levels were determined after 24 h of exposure followed by a 12 h–7 d depuration period. To assess the toxicity, snails were exposed for 28 d to irregular PS microplastics (<63 μm, 6.4–100,000 particles mL−1), both alone and in combination with copper as additional stressor. To compare the toxicity of natural and synthetic particles, we also included diatomite particles. Microplastics ingestion and excretion significantly depended on the particle size and the exposure/depuration duration. An exposure to irregular PS had no effect on survival, reproduction, energy reserves and oxidative stress. However, we observed slight effects on immune cell phagocytosis. Exposure to microplastics did not exacerbate the reproductive toxicity of copper. In addition, there was no pronounced difference between the effects of microplastics and diatomite. The tolerance towards microplastics may originate from an adaptation of L. stagnalis to particle-rich environments or a general stress resilience. In conclusion, despite high uptake rates, PS fragments do not appear to be a relevant stressor for stress tolerant freshwater gastropods considering current environmental levels of microplastics.
KW - Lymnaea stagnalis
KW - Microplastic-induced effects
KW - Mixture toxicity
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-513551
DO - https://doi.org/10.1016/j.chemosphere.2020.128040
VL - 263
SP - 128040
PB - Elsevier Ltd.
AN - OPUS4-51355
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wegner, Karl David
A1 - Hildebrandt, N.
T1 - Near infrared quantum dots for biosensing and bioimaging
N2 - Quantum dots (QDs) possess unique optoelectronic properties, which make them very attractive to be used as optical probes in biosensing and bioimaging applications. The strong absorbance and light scattering of biological compounds like tissue and blood in the visible range pose a problem. However, if optical probes emitting in the near-infrared (NIR) range are used, scattering, absorption, and autofluorescence of biological components are strongly reduced. This allows for an increased light penetration depth and higher spatial and temporal resolution for the investigation of biological processes. The synthesis and application of NIR emitting QDs is a fast-growing research field and the benefits of using QDs were demonstrated for a variety of applications, such as photoelectrochemical biosensor, in vivo vascular imaging, and fluorescence-guided surgery. This article reviews the state-of-the-art developments in the preparation of NIR/IR QDs and highlights the latest research about their utilization in biosensing and bioimaging applications.
KW - Quantum dots
KW - Near-infrared
KW - Biosensing
KW - Bioimaging
KW - NIR-II / SWIR
KW - Advanced nanomaterials
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-609708
SN - 0165-9936
DO - https://doi.org/10.1016/j.trac.2024.117922
VL - 180
SP - 1
EP - 19
PB - Elsevier B.V.
AN - OPUS4-60970
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wegner, Karl David
A1 - Resch-Genger, Ute
T1 - The 2023 Nobel Prize in Chemistry: Quantum dots
N2 - The 2023 Nobel Prize in Chemistry was awarded to Aleksey I. Ekimov (prize share 1/3), Louis E. Brus (prize share 1/3), and Moungi G. Bawendi (prize share 1/3) for groundbreaking inventions in the field of nanotechnology, i.e., for the discovery and synthesis of semiconductor nanocrystals, also termed quantum dots, that exhibit size-dependent physicochemical properties enabled by quantum size effects. This feature article summarizes the main milestones of the discoveries and developments of quantum dots that paved the road to their versatile applications in solid-state lighting, display technology, energy conversion, medical diagnostics, bioimaging, and image-guided surgery.
KW - Quantum dots
KW - Semiconductor nanocrystals
KW - Luminescence
KW - Quantitative spectroscopy
KW - Quantum yield
KW - Advanced nanomaterials
KW - Quality assurance
KW - Energy transfer
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597843
DO - https://doi.org/10.1007/s00216-024-05225-9
VL - 2024
SP - 1
EP - 11
PB - Springer
CY - Cham
AN - OPUS4-59784
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Weigert, Florian
A1 - Müller, A.
A1 - Häusler, I.
A1 - Geißler, Daniel
A1 - Skroblin, D.
A1 - Unger, Wolfgang
A1 - Radnik, Jörg
A1 - Resch-Genger, Ute
T1 - Combining HR‑TEM and XPS to elucidate the core–shell structure of ultrabright CdSe/CdS semiconductor quantum dots
N2 - Controlling thickness and tightness of surface passivation shells is crucial for many applications of core–shell nanoparticles (NP). Usually, to determine shell thickness, core and core/shell particle are measured individually requiring the availability of both nanoobjects. This is often not fulfilled for functional nanomaterials such as many photoluminescent semiconductor quantum dots (QD) used for bioimaging, solid state lighting, and display technologies as the core does not show the applicationrelevant functionality like a high photoluminescence (PL) quantum yield, calling for a whole nanoobject approach. By combining high-resolution transmission electron microscopy (HR-TEM) and X-ray photoelectron spectroscopy (XPS), a novel whole nanoobject approach is developed representatively for an ultrabright oleic acid-stabilized, thick shell CdSe/CdS QD with a PL quantum yield close to unity. The size of this spectroscopically assessed QD, is in the range of the information depth of usual laboratory XPS. Information on particle size and monodispersity were validated with dynamic light scattering (DLS) and small angle X-ray scattering (SAXS) and compared to data derived from optical measurements. In addition to demonstrating the potential of this novel whole nanoobject approach for determining architectures of small nanoparticles, the presented results also highlight challenges faced by different sizing and structural analysis methods and method-inherent uncertainties.
KW - Photoluminescence
KW - Single particle
KW - Microscopy
KW - Particle architecture
KW - Thickness
KW - SAXS
KW - Shell
KW - XPS
KW - TEM
KW - Semiconductor
KW - Quantum dot
KW - Photophysics
KW - Quantum yield
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-517911
DO - https://doi.org/10.1038/s41598-020-77530-z
VL - 10
IS - 1
SP - 20712
PB - Springer Nature
AN - OPUS4-51791
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Weller, Michael G.
T1 - The mystery of homochirality on earth
N2 - Homochirality is an obvious feature of life on Earth. On the other hand, extraterrestrial samples contain largely racemic compounds. The same is true for any common organic synthesis. Therefore, it has been a perplexing puzzle for decades how these racemates could have formed enantiomerically enriched fractions as a basis for the origin of homochiral life forms. Numerous hypotheses have been put forward as to how preferentially homochiral molecules could have formed and accumulated on Earth. In this article, it is shown that homochirality of the abiotic organic pool at the time of formation of the first self-replicating molecules is not necessary and not even probable. It is proposed to abandon the notion of a molecular ensemble and to focus on the level of individual molecules. Although the formation of the first self-replicating, most likely homochiral molecule, is a seemingly improbable event, on a closer look, it is almost inevitable that some homochiral molecules have formed simply on a statistical basis. In this case, the non-selective leap to homochirality would be one of the first steps in chemical evolution directly out of a racemic “ocean”. Moreover, most studies focus on the chirality of the primordial monomers with respect to an asymmetric carbon atom. However, any polymer with a minimal size that allows folding to a secondary structure would spontaneously lead to asymmetric higher structures (conformations). Most of the functions of these polymers would be influenced by this inherently asymmetric folding. Furthermore, a concept of physical compartmentalization based on rock nanopores in analogy to nanocavities of digital immunoassays is introduced to suggest that complex cell walls or membranes were also not required for the first steps of chemical evolution. To summarize, simple and universal mechanisms may have led to homochiral self-replicating systems in the context of chemical evolution. A homochiral monomer pool is deemed unnecessary and probably never existed on primordial Earth.
N2 - Homochiralität ist ein offensichtliches Merkmal des Lebens auf der Erde. Andererseits enthalten extraterrestrische Proben überwiegend racemische Verbindungen. Dasselbe gilt für jede gängige organische Synthese. Daher war es jahrzehntelang ein Rätsel, wie diese Racemate enantiomeren-angereicherte Fraktionen als Grundlage für den Ursprung homochiraler Lebensformen bilden konnten. Zahlreiche Hypothesen wurden aufgestellt, wie sich bevorzugt homochirale Moleküle auf der Erde gebildet und angereichert haben könnten. In diesem Artikel wird gezeigt, dass Homochiralität des abiotischen organischen Pools zum Zeitpunkt der Bildung der ersten selbstreplizierenden Moleküle nicht notwendig und nicht einmal wahrscheinlich ist. Es wird vorgeschlagen, die Vorstellung eines molekularen Ensembles aufzugeben und sich auf die Ebene der einzelnen Moleküle zu konzentrieren. Obwohl die Bildung des ersten selbstreplizierenden, höchstwahrscheinlich homochiralen Moleküls ein scheinbar unwahrscheinliches Ereignis ist, ist es bei näherer Betrachtung fast unvermeidlich, dass sich einige homochirale Moleküle einfach auf statistischer Basis gebildet haben. In diesem Fall wäre der nichtselektive Sprung zur Homochiralität einer der ersten Schritte der chemischen Evolution direkt aus einem racemischen "Ozean". Darüber hinaus konzentrieren sich die meisten Studien auf die Chiralität der ursprünglichen Monomere in Bezug auf ein asymmetrisches Kohlenstoffatom. Jedes Polymer mit einer Mindestgröße, die eine Faltung zu einer Sekundärstruktur erlaubt, würde jedoch spontan zu asymmetrischen höheren Strukturen (Konformationen) führen. Die meisten Funktionen dieser Polymere würden durch diese inhärent asymmetrische Faltung beeinflusst. Darüber hinaus wird ein Konzept der physikalischen Kompartimentierung auf der Basis von Gesteinsnanoporen in Analogie zu den Nanokavitäten digitaler Immunoassays vorgestellt, das darauf hindeutet, dass auch für die ersten Schritte der chemischen Evolution keine komplexen Zellwände oder Membranen notwendig waren. Zusammenfassend lässt sich sagen, dass einfache und universelle Mechanismen zu homochiralen selbstreplizierenden Systemen im Rahmen der chemischen Evolution geführt haben könnten. Ein homochiraler Monomerpool wird als unnötig angesehen, welcher auf der Urerde wahrscheinlich nie existiert hat.
KW - Chemical evolution
KW - Enantiomeric excess ee
KW - Chirality
KW - Racemate
KW - Folding chirality
KW - Self-assembly
KW - self-replication
KW - Single molecule
KW - Prebiotic chemistry
KW - Protein folding
KW - Peptide folding
KW - Proteinoid
KW - Conformation
KW - Segregation
KW - Compartmentalization
KW - Digital immunoassay
KW - Porous rock
KW - Miller and Urey
KW - Primordial soup
KW - Murchison meteorite
KW - Micrometeorites
KW - Tholins
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-598349
DO - https://doi.org/10.3390/life14030341
SN - 2075-1729
VL - 14
IS - 3
SP - 1
EP - 13
PB - MDPI
CY - Basel
AN - OPUS4-59834
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Weller, Michael G.
T1 - The Protocol Gap
N2 - Although peer review is considered one of the main pillars of modern science, experimental methods and protocols seem to be not a rigorous subject of this process in many papers. Commercial equipment, test kits, labeling kits, previously published concepts, and standard protocols are often considered to be not worth a detailed description or validation. Even more disturbing is the extremely biased citation behavior in this context, which sometimes leads to surrogate citations to avoid low-impact journals, preprints, or to indicate traditional practices. This article describes some of these surprising habits and suggests some measures to avoid the most unpleasant effects, which in the long term may undermine the credibility of science as a whole.
KW - Validation
KW - Peer review
KW - Experiment
KW - Documentation
KW - Scientific publication
KW - Reproducibility crisis
KW - Replication crisis
KW - Trust
KW - Citation
KW - References
KW - Surrogate citations
KW - Impact
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-521440
DO - https://doi.org/10.3390/mps4010012
SN - 2409-9279
VL - 4
IS - 1
SP - 1
EP - 5
PB - MDPI
CY - Basel
AN - OPUS4-52144
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wen, Keqing
A1 - Gorbushina, Anna
A1 - Schwibbert, Karin
A1 - Bell, Jérémy
T1 - Microfluidic platform with precisely controlled hydrodynamic parameters and integrated features for generation of microvortices to accurately form and monitor biofilms in flow
N2 - Microorganisms often live in habitats characterized by fluid flow, and their adhesion to surfaces in industrial systems or clinical settings may lead to pipe clogging, microbially influenced corrosion, material deterioration, food spoilage, infections, and human illness. Here, a novel microfluidic platform was developed to investigate biofilm formation under precisely controlled (i) cell concentration, (ii) temperature, and (iii) flow conditions. The developed platform central unit is a single-channel microfluidic flow cell designed to ensure ultrahomogeneous flow and condition in its central area, where features, e.g., with trapping properties, can be incorporated. In comparison to static and macroflow chamber assays for biofilm studies, microfluidic chips allow in situ monitoring of biofilm formation under various flow regimes and have better environment control and smaller sample requirements. Flow simulations and experiments with fluorescent particles were used to simulate bacteria flow in the platform cell for calculating flow velocity and direction at the microscale level. The combination of flow analysis and fluorescent strain injection in the cell showed that microtraps placed at the center of the channel were efficient in capturing bacteria at determined positions and to study how flow conditions, especially microvortices, can affect biofilm formation. The microfluidic platform exhibited improved performances in terms of homogeneity and robustness for in vitro biofilm formation. We anticipate the presented platform to be suitable for broad, versatile, and high-throughput biofilm studies at the microscale level.
KW - Topographical pattern
KW - E. coli
KW - Fluorescence
KW - Bacteria trapping
KW - Particle velocimetry
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-610450
DO - https://doi.org/10.1021/acsbiomaterials.4c00101
SN - 2373-9878
VL - 10
IS - 7
SP - 4626
EP - 4634
PB - ACS Publ.
CY - Washington, DC
AN - OPUS4-61045
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Westwood, Steven
A1 - Lippa, Katrice
A1 - Shimuzu, Yoshitaka
A1 - Lalerle, Beatrice
A1 - Saito, Takeshi
A1 - Duewer, David
A1 - Dai, Xinhua
A1 - Davies, Stephen
A1 - Ricci, Marina
A1 - Baldan, Annarita
A1 - Lang, Brian
A1 - Sarge, Stefan
A1 - Wang, Haifeng
A1 - Pratt, Ken
A1 - Josephs, Ralf
A1 - Mariassy, Mikael
A1 - Pfeifer, Dietmar
A1 - Warren, John
A1 - Bremser, Wolfram
A1 - Ellison, Stephen
A1 - Toman, Blaza
A1 - Nelson, Michael
A1 - Huang, Ting
A1 - Fajgelj, Ales
A1 - Gören, Ahmet
A1 - Mackay, Lindsey
A1 - Wielgosz, Robert
T1 - Methods for the SI-traceable value assignment of the purity of organic compounds (IUPAC Technical Report)
N2 - The “purity” of an organic compound typically refers, in practice, to an assignment of the mass fraction content of the primary organic component present in the material. The “purity” value of an organic primary calibrator material is the ultimate source of metrological traceability of any quantitative measurement of the content of that compound in a given matrix. The primary calibrator may consist of a Certified Reference Material (CRM) whose purity has been assigned by the CRM producer or a laboratory may choose to value-assign a material to the extent necessary for their intended application by using appropriately valid methods. This report provides an overview of the approach, performance and applicability of the principal methods used to determine organic purity including mass balance, quantitative NMR, thermal methods and direct-assay techniques. A statistical section reviews best practice for combination of data, value assignment as the upper limit values corresponding to 100 % purity are approached and how to report and propagate the standard uncertainty associated with the assigned values.
KW - Calibration hierarchy
KW - Certified reference materials
KW - Mass balance
KW - Measurement uncertainty
KW - Organic purity
KW - Primary calibrators
KW - Primary reference materials
KW - qNMR
KW - Related-structure impurities
KW - Thermal analysis
KW - Titrimetry
KW - Traceability
KW - Uncertainty propagation
KW - Volatile organic compounds
KW - Water content
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-627932
DO - https://doi.org/10.1515/pac-2020-0804
SN - 0033-4545
SN - 1365-3075
VL - 95
IS - 1
SP - 1
EP - 77
PB - de Gruyter
CY - Berlin
AN - OPUS4-62793
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wetzel, Annica
A1 - Morell, Daniel
A1 - von der Au, Marcus
A1 - Witt, Julia
A1 - Özcan Sandikcioglu, Özlem
T1 - Transpassive Behavior of Equimolar CrMnFeCoNi and CrCoNi Multi‐Principal Element Alloys in an Alkaline NaCl Electrolyte
N2 - AbstractWe investigated the corrosion properties and transpassive behavior of CrMnFeCoNi and CrCoNi multi‐principal element alloys (MPEAs) in a 0.1 M NaCl electrolyte at pH 12. By using SECM‐based tip substrate voltammetry (TSV) in combination with the chemical analysis of the electrolyte, we were able to differentiate between anodic metal dissolution and oxygen evolution in the transpassive range. Our investigations have shown that CrCoNi has a significantly higher corrosion resistance compared to CrMnFeCoNi. In the studied alkaline environment, a transpassive oxide film is formed on the surface of CrCoNi during secondary passivation. This transpassive oxide film appears to play a significant role in oxygen evolution, as the increase in TSV currents at the microelectrode coincides with the corresponding current density plateau of the voltametric current trace. The formation of the transpassive oxide film was not observed in previous studies conducted in acidic environments. Moreover, the alkaline electrolyte induced a positive hysteresis and mild pitting corrosion, in addition to intergranular corrosion, which was the sole corrosion process observed at acidic pH levels. These findings enhance the understanding of the processes governing the transpassivity of CrMnFeCoNi and CrCoNi MPEAs in alkaline environments and have potential implications for the development of application‐tailored corrosion‐resistant MPEAs.
KW - Multi-principal element alloys
KW - MPEA
KW - Corrosion
KW - Oxygen evolution reaction
KW - Transpassive region
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-611594
DO - https://doi.org/10.1002/celc.202400346
SN - 2196-0216
SP - 1
EP - 9
PB - Wiley
AN - OPUS4-61159
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wetzel, Annica
A1 - Morell, Daniel
A1 - von der Au, Marcus
A1 - Wittstock, Gunther
A1 - Özcan Sandikcioglu, Özlem
A1 - Witt, Julia
T1 - Transpassive Metal Dissolution vs. Oxygen Evolution Reaction: Implication for Alloy Stability and Electrocatalysis
T1 - Transpassive Metallauflösung vs. Sauerstoffentwicklung:
Auswirkungen auf Legierungsstabilität und Elektrokatalyse
N2 - Multi-principal element alloys (MPEAs) are gaining interest in corrosion and electrocatalysis research due to their electrochemical stability across a broad pH range and the design flexibility they offer. Using the equimolar CrCoNi alloy, we observe significant metal dissolution in a corrosive electrolyte (0.1 M NaCl, pH 2) concurrently with the oxygen evolution reaction (OER) in the transpassive region despite the absence of hysteresis in polarization curves or other obvious corrosion indicators. We present a characterization scheme to delineate the contribution of OER and alloy dissolution, using scanning electrochemical microscopy (SECM) for OER-onset detection, and quantitative chemical analysis with inductively coupled-mass spectrometry (ICP-MS) and ultraviolet visible light (UV-Vis) spectroscopy to elucidate metal dissolution processes. In-situ electrochemical atomic force microscopy (EC-AFM) revealed that the transpassive metal dissolution on CrCoNi is dominated by intergranular corrosion. These results have significant implications for the stability of MPEAs in corrosion systems, emphasizing the necessity of analytically determining metal ions released from MPEA electrodes into the electrolyte when evaluating Faradaic efficiencies of OER catalysts. The release of transition metal ions not only reduces the Faradaic efficiency of electrolyzers but may also cause poisoning and degradation of membranes in electrochemical reactors.
N2 - Multi-Hauptelement-Legierungen (MPEAs) gewinnen in der Korrosions- und Elektrokatalyseforschung aufgrund ihrer elektrochemischen Stabilität über einen breiten pH-Bereich und der Vielfalt der möglichen chemischen Zusammensetzungen zunehmend an Interesse. In unseren Untersuchungen mit der äquimolaren CrCoNi-Legierung in einem sauren Elektrolyten (0.1 M NaCl, pH 2) beobachteten wir eine signifikante Metallauflösung, die mit der Sauerstoffentwicklungsreaktion (OER) im transpassiven Bereich einhergeht, obwohl in zyklischen Polarisationskurven keine Hysterese auftrat oder andere offensichtliche Korrosionsindikatoren vorlagen. In diesem Artikel wird ein Charakterisierungskonzept eingeführt, dass die Beiträge der OER und der Legierungsauflösung differenziert. Hierfür kommt die elektrochemische Rastermikroskopie (SECM) zum Nachweis des Beginns der OER und die quantitative chemische Analyse mit induktiv gekoppelter Massenspektrometrie (ICP-MS) und UV/Vis-Spektrometrie zur Aufklärung der Metallauflösungsprozesse zum Einsatz. Die elektrochemische In situ-Atomkraftmikroskopie (EC-AFM) zeigte, dass die intergranulare Korrosion der dominierende Mechanismus der transpassive Metallauflösung von CrCoNi ist. Diese Ergebnisse besitzen erhebliche Auswirkungen für die Beurteilung der Stabilität von MPEAs in Korrosionssystemen und der Stromausbeute von OER-Katalysatoren auf der Basis von MPEAs. Die Daten unterstreichen die Notwendigkeit der analytischen Bestimmung von Metallionen, die von MPEA-Elektroden freigesetzt werden. Die Freisetzung von Übergangsmetallionen verringert nicht nur die Stromausbeute von Elektrolyseuren, sondern kann zu einer Schädigung von Membranen in elektrochemischen Reaktoren führen.
KW - Transpassive dissolution
KW - Corrosion
KW - Multi-prinicpal element alloys (MPEAs)
KW - Passivation
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597045
DO - https://doi.org/10.1002/anie.202317058
SP - 1
EP - 8
PB - Wiley VHC-Verlag
AN - OPUS4-59704
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wetzel, Annica
A1 - von der Au, Marcus
A1 - Dietrich, P. M.
A1 - Radnik, Jörg
A1 - Özcan Sandikcioglu, Özlem
A1 - Witt, Julia
T1 - The comparison of the corrosion behavior of the CrCoNi medium entropy alloy and CrMnFeCoNi high entropy alloy
N2 - This work presents the determination of the corrosion characteristics of CrCoNi (medium entropy alloy) and CrMnFeCoNi (high entropy alloy) in 0.1 M NaCl and 0.1 M H2SO4. The morphology and chemical composition of the oxide layers formed on CrCoNi and CrMnFeCoNi were comparatively analyzed by scanning Kelvin probe microscopy (SKPFM) and scanning electron microscopy (SEM) and supported with chemical analysis by means of inductively coupled plasma mass spectrometry (ICP-MS) and X-Ray photoelectron spectroscopy (XPS). The analysis of the 3p core level peaks showed that the oxide layer (native and after anodic passivation) on CrCoNi consisted mainly of Cr oxides, while the oxide layer on CrMnFeCoNi was primarily composed of a mixture of Cr and Fe oxides. In addition, XPS was utilized to assess the oxide layer thicknesses. These results were compared to the thicknesses obtained by means of electrochemical impedance spectroscopy (EIS), with both approaches yielding values up to about 4 nm depending on the electrolyte and the alloy. Cyclic polarization measurements indicated superior corrosion resistance of CrCoNi in both aqueous environments compared to CrMnFeCoNi, as well as to AISI 304 stainless steel.
KW - Medium entropy alloy
KW - High entropy alloy
KW - SKPFM
KW - XPS
KW - Passivation
KW - Corrosion
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559902
DO - https://doi.org/10.1016/j.apsusc.2022.154171
SN - 0169-4332
VL - 601
SP - 1
EP - 10
PB - Elsevier B.V.
AN - OPUS4-55990
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Winckelmann, Alexander
A1 - Morcillo Garcia-Morato, Dalia
A1 - Richter, Silke
A1 - Recknagel, Sebastian
A1 - Riedel, Jens
A1 - Vogl, Jochen
A1 - Panne, Ulrich
A1 - Abad Andrade, Carlos Enrique
T1 - Determination of lithium in human serum by isotope dilution atomic absorption spectrometry
N2 - The therapeutic dose of lithium (Li) compounds, which are widely used for the treatment of psychiatric and hematologic disorders, is close to its toxic level; therefore, drug monitoring protocols are mandatory. Herein, we propose a fast, simple, and low-cost analytical procedure for the traceable determination of Li concentration in human serum, based on the monitoring of the Li isotope dilution through the partially resolved isotope shift in its electronic transition around 670.80 nm using a commercially available high-resolution continuum source graphite furnace atomic absorption spectrometer. With this technique, serum samples only require acidic digestion before analysis. The procedure requires three measurements—an enriched 6Li spike, a mixture of a certified standard solution and spike, and a mixture of the sample and spike with a nominal 7Li/6Li ratio of 0.82. Lanthanum has been used as an internal spectral standard for wavelength correction. The spectra are described as the linear superposition of the contributions of the respective isotopes, each consisting of a spin-orbit doublet, which can be expressed as Gaussian components with constant spectral position and width and different relative intensity, reflecting the isotope ratio in the sample. Both the spectral constants and the correlation between isotope ratio and relative band intensity have been experimentally obtained using commercially available materials enriched with Li isotopes. The Li characteristic mass (mc) obtained corresponds to 0.6 pg. The procedure has been validated using five human serum certified reference materials. The results are metrologically comparable and compatible to the certified values. The measurement uncertainties are comparable to those obtained by the more complex and expensive technique, isotope dilution mass spectrometry.
KW - Lithium
KW - Human serum
KW - Isotope dilution
KW - Atomic absorption spectrometry
KW - High-resolution continuum source graphite furnace atomic absorption spectrometry
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-532446
DO - https://doi.org/10.1007/s00216-021-03636-6
VL - 414
IS - 1
SP - 251
EP - 256
PB - Springer
CY - Berlin
AN - OPUS4-53244
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Winckelmann, Alexander
A1 - Nowak, S.
A1 - Richter, Silke
A1 - Recknagel, Sebastian
A1 - Riedel, Jens
A1 - Vogl, Jochen
A1 - Panne, Ulrich
A1 - Abad Andrade, Carlos Enrique
T1 - High-Resolution Atomic Absorption Spectrometry Combined With Machine Learning Data Processing for Isotope Amount Ratio Analysis of Lithium
N2 - An alternative method for lithium isotope amount ratio analysis based on a combination of high-resolution atomic absorption spectrometry and spectral data analysis by machine learning (ML) is proposed herein. It is based on the well-known isotope shift of approximately 15 pm for the electronic transition 22P←22S at around the wavelength of 670.8 nm, which can be measured by the state-of-the-art high-resolution continuum source graphite furnace atomic absorption spectrometry. For isotope amount ratio analysis, a scalable tree boosting ML algorithm (XGBoost) was employed and calibrated using a set of samples with 6Li isotope amount fractions, ranging from 0.06 to 0.99 mol mol–1, previously determined by a multicollector inductively coupled plasma mass spectrometer (MC-ICP-MS). The calibration ML model was validated with two certified reference materials (LSVEC and IRMM-016). The procedure was applied toward the isotope amount ratio determination of a set of stock chemicals (Li2CO3, LiNO3, LiCl, and LiOH) and a BAM candidate reference material NMC111 (LiNi1/3Mn1/3Co1/3O2), a Li-battery cathode material. The results of these determinations were compared with those obtained by MC-ICP-MS and found to be metrologically comparable and compatible. The residual bias was −1.8‰, and the precision obtained ranged from 1.9 to 6.2‰. This precision was sufficient to resolve naturally occurring variations, as demonstrated for samples ranging from approximately −3 to +15‰. To assess its suitability to technical applications, the NMC111 cathode candidate reference material was analyzed using high-resolution continuum source atomic absorption spectrometry with and without matrix purification. The results obtained were metrologically compatible with each other.
KW - Lithium
KW - Isotope
KW - Machine learning
KW - Algorithms
KW - Reference material
KW - AAS
KW - Atomic Absorption Spectrometry
PY - 2021
DO - https://doi.org/10.1021/acs.analchem.1c00206
SN - 1520-6882
VL - 93
IS - 29
SP - 10022
EP - 10030
PB - American Chemical Society
CY - Washington, DC, USA
AN - OPUS4-53028
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Winckelmann, Alexander
A1 - Roik, Janina
A1 - Recknagel, Sebastian
A1 - Abad Andrade, Carlos Enrique
A1 - You, Zengchao
T1 - Investigation of matrix effects in nitrogen microwave inductively coupled atmospheric-pressure plasma mass spectrometry (MICAP-MS) for trace element analysis in steels
N2 - We investigated the performance of nitrogen microwave inductively coupled atmospheric-pressure plasma mass spectrometry (MICAP-MS) under matrix effects and its applicability to trace element analysis in steels. Influences of different gas flows and ion optics on the matrix tolerance are studied, indicating that nebulizer gas flow has the most significant impact. Optimization of ion optics improves matrix tolerance for light elements due to the reduction of the inelastic collisional scattering effect. With optimized operating conditions, MICAP-MS achieves an internal standard intensity recovery of over 90% at an Fe concentration of 500 mg L−1. Even at an Fe concentration of 1 g L−1, the recovery remains above 80%. Three certified reference materials – non-alloy, low-alloy and high-alloy steel – were analyzed using MICAP-MS. The determined mass concentrations of the trace and minor components show metrological compatibility to the reference values. No significant differences are observed between the results obtained with aqueous and matrix-matched calibration, demonstrating the strong matrix tolerance of MICAP-MS, and its promising applicability to steel analysis.
KW - MICAP-MS
KW - Trace Analysis
KW - Steel
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-576323
DO - https://doi.org/10.1039/d3ja00088e
SN - 0267-9477
VL - 38
IS - 6
SP - 1253
EP - 1260
PB - Royal Society of Chemistry
AN - OPUS4-57632
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Witte, F.
A1 - Rietsch, P.
A1 - Nirmalananthan-Budau, Nithiya
A1 - Weigert, Florian
A1 - Götze, J. P.
A1 - Resch-Genger, Ute
A1 - Eigler, S.
A1 - Paulus, B.
T1 - Aggregation-induced emission leading to two distinct emissive species in the solid-state structure of high-dipole organic chromophores
N2 - The concept of aggregation-induced emission represents a means to rationalise photoluminescence of usually nonfluorescent excimers in solid-state materials. In this publication, we study the photophysical properties of selected diaminodicyanoquinone (DADQ) derivatives in the solid state using a combined approach of experiment and theory. DADQs are a class of high-dipole organic chromophores promising for applications in non-linear optics and light-harvesting devices. Among the compounds investigated, we find both aggregation-induced emission and aggregation-caused quenching effects rationalised by calculated energy transfer rates. Analysis of fluorescence spectra and lifetime measurements provide the interesting result that (at least) two emissive species seem to contribute to the photophysical properties of DADQs. The main emission peak is notably broadened in the long-wavelength limit and exhibits a blue-shifted shoulder. We employ high-level quantum-chemical methods to validate a molecular approach to a solid-state problem and show that the complex emission features of DADQs can be attributed to a combination of H-type aggregates, monomers, and crystal structure defects.
KW - Fluorescence
KW - Optical probe
KW - Dye
KW - Photophysics
KW - Theory
KW - Quantum yield
KW - Mechanism
KW - Quantum chemistry
KW - Modelling
KW - Aggregation
KW - Lifetime
KW - Single particle
KW - Microscopy
KW - Solid
KW - Crystal
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-531138
DO - https://doi.org/10.1039/d1cp02534a
SP - 1
EP - 9
PB - Royal Society of Chemistry
AN - OPUS4-53113
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Wittwer, Philipp
A1 - Roesch, Philipp
A1 - Vogel, Christian
A1 - Simon, Fabian
A1 - Gehrenkemper, Lennart
A1 - Feldmann, Ines
A1 - Simon, Franz-Georg
T1 - Less Is More: Influence of Cross-Linking Agent Concentration on PFOS Adsorption in Chitosan
N2 - As a result of the continuous use of persistent per- and polyfluoroalkyl substances (PFAS), e.g., in aviation firefighting foams, contamination with PFAS has been found in soil, groundwater, and surface water around thousands of industrial and military installations. Due to their harmful (environmental) potential, further dispersion in the environment needs to be stopped, which can be achieved by appropriate absorption materials. In this work, the influence of the cross-linking agent epichlorohydrin (ECH) concentration on the perfluorooctanesulfonic acid (PFOS) adsorption capacity of chitosan gel was investigated. It was found that higher ECH concentration during the cross-linking step decreases the PFOS adsorption capacity of the cross-linked chitosan gel from 0% to 4% ECH solution by about 15%. Using a concentration of 1%, ECH resulted still in an acid-stable material, and a maximum PFOS loading capacity of 4.04 mmol/g was obtained, one of the highest described in the literature. Furthermore, we used a rapid small-scale column test to compare the PFOS adsorption capacity of chitosan and activated carbon, each in both milled and unmilled form. Unmilled chitosan showed the highest PFOS adsorption capacity considering adsorption material dry masses (>0.9 and <0.4 mmol/g for both types of chitosan and activated carbon, respectively). Milled activated carbon proved to be the better adsorption material, considering the fixed volume of the adsorber (>99.9% PFOS adsorbed). Overall, the cross-linking agent concentration in chitosan is a crucial factor influencing its PFOS absorption potential. Our results feature cross-linked chitosan as an effective economic and ecologic alternative for PFOS adsorption in aqueous solutions.
KW - Combustion Ion Chromatography
KW - Per- and Polyfluoroalkyl substances (PFAS)
KW - Remediation
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-618406
DO - https://doi.org/10.3390/app142311145
VL - 14
IS - 23
SP - 1
EP - 13
PB - MDPI
AN - OPUS4-61840
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Würth, Christian
A1 - Behnke, Thomas
A1 - Gienger, J.
A1 - Resch-Genger, Ute
T1 - Efficiency scale for scatteringluminescent particles linkedto fundamental and measurablespectroscopic properties
N2 - Comparing the performance of molecular and nanoscale luminophores and luminescent microand nanoparticles and estimating achievable signal amplitudes and limits of detection requires a standardizable intensity scale. This initiated the development of the relative MESF (number of molecules of equivalent soluble fluorochromes) and ERF (equivalent reference fluorophores) scales for flow cytometry and fluorescence microscopy. Both intensity scales rely on fluorescence intensity values assigned to fluorescent calibration beads by an intensity comparison to spectrally closely matching fluorophore solutions of known concentration using a spectrofluorometer. Alternatively, the luminophore or bead brightness (B) can be determined that equals the product of the absorption cross section (σa) at the excitation wavelength (σa(λex)) and the photoluminescence quantum yield (Φpl).
Thereby, an absolute scale based on fundamental and measurable spectroscopic properties can be realized which is independent of particle size, material, and luminophore staining or labeling density and considers the sensitivity of the optical properties of luminophores to their environment. Aiming for establishing such a brightness scale for light-scattering dispersions of luminescent particles with sizes exceeding a few ten nanometers, we demonstrate how the brightness of quasi-monodisperse 25 nm, 100 nm, and 1 μm sized polystyrene particles (PSP), loaded with two different dyes in varying concentrations, can be obtained with a single custom-designed integrating sphere setup that enables the absolute determination of Φpl and transmittance and diffuse reflectance measurements. The resulting Φpl, σa(λex), imaginary parts of the refractive index, and calculated B values of these samples are given in dependence of the number of incorporated dye molecule per particle. Finally, a unitless luminescence efficiency (LE) is defined allowing for the direct comparison of luminescence efficiencies of particles with different sizes.
KW - Brightness
KW - Quantum yield
KW - Cross section
KW - Lluminescence
PY - 2023
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-573680
DO - https://doi.org/10.1038/s41598-023-32933-6
VL - 13
IS - 1
SP - 14
PB - Nature
AN - OPUS4-57368
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Würth, Christian
A1 - Grauel, Bettina
A1 - Pons, Monika
A1 - Frenzel, Florian
A1 - Rissiek, P.
A1 - Rücker, Kerstin
A1 - Haase, Markus
A1 - Resch-Genger, Ute
T1 - Yb- and Er concentration dependence of the upconversion luminescence of highly doped NaYF4:Yb,Er/NaYF4:Lu core/shell nanocrystals prepared by a water-free synthesis
N2 - High sensitizer and activator concentrations have been increasingly examined to improve the performance of multi-color emissive upconversion (UC) nanocrystals (UCNC) like NaYF4:Yb,Er and first strategies were reported to reduce concentration quenching in highly doped UCNC. UC luminescence (UCL) is, however, controlled not only by dopant concentration, yet by an interplay of different parameters including size, crystal and shell quality, and excitation power density (P). Thus, identifying optimum dopant concentrations requires systematic studies of UCNC designed to minimize additional quenching pathways and quantitative spectroscopy. Here, we quantify the dopant concentration dependence of the UCL quantum yield (ΦUC) of solid
NaYF4:Yb,Er/NaYF4:Lu upconversion core/shell nanocrystals of varying Yb3+ and Er3+ concentrations (Yb3+ series: 20%‒98% Yb3+; 2% Er3+; Er3+ series: 60% Yb3+; 2%‒40% Er3+). To circumvent other luminescence quenching processes, an elaborate synthesis yielding OH-free UCNC with record ΦUC of ~9% and ~25 nm core particles with a thick surface shell were used. High Yb3+ concentrations barely reduce ΦUC from ~9% (20% Yb3+) to ~7% (98% Yb3+) for an Er3+ concentration of 2%, thereby allowing to strongly increase the particle absorption cross section and UCNC brightness. Although an increased Er3+ concentration reduces ΦUC from ~7% (2% Er3+) to 1% (40%) for 60% Yb3+. Nevertheless, at very high P (> 1 MW/cm2) used for microscopic studies, highly Er3+-doped UCNC display a high brightness because of reduced saturation. These findings underline the importance of synthesis control and will pave the road to many fundamental studies of UC materials.
KW - Upconverion
KW - Nanoparticle
KW - Lanthanides
KW - Quantum yield
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-551346
DO - https://doi.org/10.1007/s12274-022-4570-5
SP - 1
EP - 8
PB - Springer
AN - OPUS4-55134
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Xu, R.
A1 - Teich, W.
A1 - Frenzel, Florian
A1 - Hoffmann, Katrin
A1 - Radke, J.
A1 - Rösler, J.
A1 - Faust, K.
A1 - Blank, A.
A1 - Brandenburg, S.
A1 - Misch, M.
A1 - Vajkoczy, P.
A1 - Onken, J. S.
A1 - Resch-Genger, Ute
T1 - Optical characterization of sodium fluorescein in vitro and ex vivo
N2 - Objective: The utilization of fluorescein-guided biopsies and resection has been recently discussed as a suitable strategy to improve and expedite operative techniques for the resection of central nervous system (CNS) tumors. However, little is known about the optical properties of sodium fluorescein (NaFl) in human tumor tissue and their potential impact on ex vivo analyses involving fluorescence-based methods.
Methods: Tumor tissue was obtained from a study cohort of an observational study on the utilization of fluorescein-guided biopsy and resection (n=5). The optical properties of fluorescein-stained tissue were compared to the optical features of the dye in vitro and in control samples consisting of tumor tissue of high-grade glioma patients (n=3) without intravenous (i.v.) application of NaFl. The dye-exposed tumor tissues were used for optical measurements to confirm the detectability of NaFl emission ex vivo. The tissue samples were fixed in 4%PFA, immersed in 30% sucrose, embedded in Tissue-Tek OCT compound, and cut to 10 mm cryosections. Spatially resolved emission spectra from tumor samples were recorded on representative slides with a Confocal Laser Scanning Microscope FV1000 (Olympus GmbH, Hamburg, Germany) upon excitation with lexc = 488 nm.
Results: Optical measurements of fluorescein in 0.9% sodium chloride (NaCl) under in vitro conditions showed an absorption maximum of lmax abs = 479 nm as detected with spectrophotometer Specord 200 and an emission peak at lmax em = 538 nm recorded with the emCCD detection system of a custom-made microscope-based single particle setup using a 500 nm long-pass filter. Further measurements revealed pH- and concentration-dependent emission spectra of NaFl. Under ex vivo conditions, confocal laser scanning microscopy of fluorescein tumor samples revealed a slight bathochromic shift and a broadening of the emission band.
Conclusion: Tumor uptake of NaFl leads to changes in the optical properties – a bathochromic shift and broadening of the emission band – possibly caused by the dye’s high pH sensitivity and concentration-dependent reabsorption acting as an innerfilter of the dye’s emission, particularly in the short wavelength region of the Emission spectrum where absorption and fluorescence overlap. Understanding the ex vivo optical properties of fluorescein is crucial for testing and validating its further applicability as an optical probe for intravital microscopy, immunofluorescence localization studies, and flow cytometry analysis.
KW - Fluorescence
KW - Optical probe
KW - Sensor
KW - Fluorescein
KW - PH
KW - Imaging
KW - Tissue
KW - Cancer
KW - Medical diagnostics
KW - Tumor
KW - In vivo
KW - Ex vivo
KW - Quantum yield
KW - Dye
KW - Quality assurance
KW - Microscopy
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-527843
DO - https://doi.org/10.3389/fonc.2021.654300
SN - 2234-943X
VL - 11
SP - 1
EP - 8
PB - Frontiers Media
CY - Lausanne
AN - OPUS4-52784
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Xue, Boyang
A1 - Wang, Zhangjun
A1 - Zhu, Tao
A1 - Gu, Yezhen
A1 - Sun, Weihong
A1 - Chen, Chao
A1 - Li, Zhigang
A1 - Riedel, Jens
A1 - You, Yi
T1 - High repetition-rate laser-induced breakdown spectroscopy combined with two-dimensional correlation method for analysis of sea-salt aerosols
N2 - Laser-induced breakdown spectroscopy (LIBS) offers a tantalizing glimpse into real-time, on-the-spot aerosol analysis. Yet, the reliance on traditional lasers, with their limitations in energy and frequency, hampers optimal sample handling, dissociation, and excitation. To address those challenges, we propose a novel tactic: utilize a high repetition-rate (rep.-rate) laser with low pulse energy in combination with the two-dimensional correlation (2D-corr.) technique for sea-salt aerosols analyses. By examining the emission patterns from both the laser pulse train and individual pulses, we recognize distinctive analyte-specific rep.-rate responses, which allowed spectral reconstruction of analytes, avoiding background interferences. This discovery enabled the rep.-rate modulation for a 2D-corr. spectroscopy workflow. Consequently, we successfully differentiated between particle-related and air-species-related spectral components, obviating expensive spectrometers or intensified image detectors. For instance, the Na I at 589 nm stemming from aerosols exhibited an entirely different correlation contribution compared to O I at 777 nm, resulting in reconstructed clean aerosol-spectra without spectral peaks originated from air species. This 2D-corr. aerosol LIBS approach shows promising analytical potential streamlining aerosol particle analysis.
KW - LIBS
KW - Aerosol
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-613392
DO - https://doi.org/10.1016/j.sab.2024.107048
SN - 0584-8547
VL - 221
SP - 1
EP - 8
PB - Elsevier
AN - OPUS4-61339
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Yanbaeva, M.
A1 - Soyka, J.
A1 - Holthoff, J. M.
A1 - Rietsch, P.
A1 - Engelage, E.
A1 - Ruff, A.
A1 - Resch-Genger, Ute
A1 - Weiss, R.
A1 - Eigler, S.
A1 - Huber, S. M.
T1 - Dimethylene-Cyclopropanide Units as Building Blocks for Fluorescence Dyes
N2 - Many organic dyes are fluorescent in solution. In the solid state, however, quenching processes often dominate, hampering material science applications such as light filters, light-emitting devices, or coding tags. We show that the dimethylene-cyclopropanides caffold can be used to form two structurally different types of chromophores, which feature fluorescence quantum yields up to 0.66 in dimethyl sulfoxide and 0.53 in
solids. The increased fluorescence in the solid state for compounds bearing malonate substituents instead of dicyanomethide ones is rationalized by the induced twist between the planes of the cyclopropanide core and a pyridine ligand.
KW - Fluorescence
KW - Dye
KW - Sensor
KW - Quantum yield
KW - Spectroscopy
KW - Photophysics
KW - Synthesis
KW - Solvatochromism
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-614931
DO - https://doi.org/10.1002/chem.202402476
VL - 30
IS - 56
SP - 1
EP - 7
PB - Chemistry - A European Journal
AN - OPUS4-61493
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - You, Yi
A1 - Danischewski, Julia
A1 - Molnar, Brian
A1 - Riedel, Jens
A1 - Shelley, Jacob
T1 - Manipulation of Gaseous Ions with Acoustic Fields at Atmospheric Pressure
N2 - The ability to controllably move gaseous ions is an essential aspect of ion-based spectrometry (e.g., mass spectrometry and ion mobility spectrometry) as well as materials processing. At higher pressures, ion motion is largely governed by diffusion and multiple collisions with neutral gas molecules. Thus, high-pressure ion optics based on electrostatics require large fields, radio frequency drives, complicated geometries, and/or partially transmissive grids that become contaminated. Here, we demonstrate that low-power standing acoustic waves can be used to guide, block, focus, and separate beams of ions akin to electrostatic ion optics. Ions preferentially travel through the static-pressure regions (“nodes”) while neutral gas does not appear to be impacted by the acoustic field structure and continues along a straight trajectory. This acoustic ion manipulation (AIM) approach has broad implications for ion manipulation techniques at high pressure, while expanding our fundamental understanding of the behavior of ions in gases.
KW - Ion mobility spectrometry
KW - Acoustic
KW - Mass spectrometry
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600704
DO - https://doi.org/10.1021/jacs.4c01224
SP - 1
EP - 6
PB - ACS Publications
AN - OPUS4-60070
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - You, Yi
A1 - Riedel, Jens
T1 - Approaching phase-imaging through defocusing shadowgraphy for acoustic resonator diagnosis and the capability of direct index-of-refraction measurements
N2 - The visualization of index-of-refraction (IoR) distribution is one of the common methods to investigate fluid flow or pressure fields. While schlieren and shadowgraphy imaging techniques are widely accepted, their inherent limitations often lead to difficulties in elucidating the IoR distribution and extracting the true IoR information from the resulting images. While sophisticated solutions exist, the IoR-gradient-to-image was achieved by purposely introducing a commonly avoided “defect” into the optical path of a conventional coincident schlieren/shadowgraphy setup; the defect is a combination of slight defocusing and the use of non-conjugate optical components. As such, the method presented in this work is referred to as defocusing shadowgraphy, or DF-shadowgraphy. While retaining the ease of a conventional schlieren/shadowgraphy geometry, this DF approach allows direct visualization of complicated resonant acoustic fields even without any data processing. For instance, the transient acoustic fields of a common linear acoustic resonator and a two-dimensional one were directly visualized without inversion. Moreover, the optical process involved in DF-shadowgraphy was investigated from a theoretical perspective. A numerical solution of the sophisticated impulse response function was obtained, which converts the phase distortion into intensity distributions. Based on this solution, the IoRs of various gas streams (e.g., CO2 and isopropanol vapor) were determined from single images.
KW - Imaging Technique
KW - Phase Imaging
KW - Shadowgraphy
KW - Schlieren Imaging
PY - 2021
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-537116
DO - https://doi.org/10.1063/5.0058334
SN - 1089-7623
VL - 92
IS - 10
SP - 103703
PB - AIP Publishing Group
AN - OPUS4-53711
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - You, Yi
A1 - Xue, Boyang
A1 - Riedel, Jens
T1 - Enhancement of LIBS plasma in air with organic solvent vapors
N2 - Laser-induced breakdown spectroscopy (LIBS) offers versatile, field-deployable elemental analysis; however, compact, high-repetition-rate nanosecond laser systems typically face constraints in power consumption and size, often compromising emission intensity and thus analytical performance. We demonstrate a significant improvement in LIBS signals through the controlled introduction of common organic solvent vapors into a sheath gas, with a diode-pumped solid-state laser (1064 nm, 2–28 kHz repetition rate, 450–600-μJ pulse energy). Optical and acoustic diagnostics reveal up to ca. 40-fold enhancement of the N II emission line at 567 nm when ambient air serves as the analyte. Maximal enhancement occurs at intermediate repetition rates of ca. 15 kHz, particularly at pulse energies approaching the optical breakdown threshold; this observation suggests a viable strategy for operating LIBS at lower pulse energies and higher repetition rates. Enhancement effects scale jointly with both vapor pressure and ionization energy of the organic species, with acetone and toluene markedly outperforming methanol and isopropanol. These findings provide a rational foundation for significantly improving the analytical performance of portable LIBS instruments without exceeding platform-specific constraints.
KW - LIBS
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653758
DO - https://doi.org/10.1016/j.sab.2025.107309
SN - 0584-8547
VL - 236
SP - 1
EP - 6
PB - Elsevier B.V.
AN - OPUS4-65375
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - You, Zengchao
A1 - Akkus, Asli
A1 - Weisheit, W.
A1 - Giray, Thorsten
A1 - Penk, Sibylle
A1 - Buttler, Sabine
A1 - Recknagel, Sebastian
A1 - Abad Andrade, Carlos Enrique
T1 - Multielement analysis in soils using nitrogen microwave inductively coupled atmospheric pressure plasma mass spectrometry
N2 - In this study, we employed nitrogen microwave inductively coupled atmospheric-pressure plasma (MICAP) combined with quadrupole mass spectrometry (MS) and a liquid sample introduction system to analyze heavy metals in soils. The vanadium, cobalt, nickel, zinc, copper, chromium, arsenic, lead, and cadmium contents in seven reference and three environmental soil samples determined using MICAP-MS were within the uncertainty of the reference values, indicating that MICAP-MS is promising for soil analysis similar to the conventional inductively coupled plasma mass spectrometry (ICP-MS) technique. In addition, the limits of detection (LODs) and sensitivity of both techniques using N2 and Ar plasma were of the same order of magnitude. Furthermore, the performance of MICAP-MS under different N2 purity was investigated, and we found that the plasma formation and ionization efficiency were not influenced by the impurities in the gas. A prominent advantage of MICAP-MS is the low operating cost associated with gas consumption. In this work, MICAP-MS used nitrogen, which is cheaper than argon, and consumed 25% less gas than ICP-MS. Using low-purity N2 can further reduce the gas cost, making MICAP-MS more cost effective than ICP-MS. These results suggest that MICAP-MS is a promising alternative to ICP-MS for the analysis of heavy metals in the soil.
KW - Soil
KW - Microwave inductively coupled atmospheric pressure mass spectrometry (MICAP-MS)
KW - Nitrogen plasma
KW - Multi-element analysis
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-561048
DO - https://doi.org/10.1039/d2ja00244b
SN - 0267-9477
VL - 37
IS - 12
SP - 2556
EP - 2562
PB - Royal Society of Chemistry
CY - Cambridge
AN - OPUS4-56104
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - You, Zengchao
A1 - Winckelmann, Alexander
A1 - Vogl, Jochen
A1 - Recknagel, Sebastian
A1 - Abad Andrade, Carlos Enrique
T1 - Determination of calcium, iron, and selenium in human serum by isotope dilution analysis using nitrogen microwave inductively coupled atmospheric pressure plasma mass spectrometry (MICAP-MS)
N2 - In this study, we demonstrate the applicability of nitrogen microwave inductively coupled atmospheric pressure mass spectrometry (MICAP-MS) for Ca, Fe, and Se quantification in human serum using isotope dilution (ID) analysis. The matrix tolerance of MICAP-MS in Na matrix was investigated, uncovering that high Na levels can suppress the signal intensity. This suppression is likely due to the plasma loading and the space charge effect. Moreover, 40Ca and 44Ca isotopic fractionation was noted at elevated Na concentration. Nine certified serum samples were analyzed using both external calibration and ID analysis. Overestimation of Cr, Zn, As, and Se was found in the results of external calibration, which might be resulted from C-induced polyatomic interference and signal enhancement, respectively. Further investigations performed with methanol showed a similar enhancement effect for Zn, As, and Se, potentially supporting this assumption. The mass concentrations determined with ID analysis show metrological compatibility with the reference values, indicating that MICAP-MS combined with ID analysis can be a promising method for precise Ca, Fe, and Se determination. Moreover, this combination reduces the influences of matrix effects, broadening the applicability of MICAP-MS for samples with complex matrix.
KW - Selenium
KW - Nitrogen microwave inductively coupled atmospheric pressure mass spectrometry
KW - Isotope dilution
KW - Human serum
KW - Calcium
KW - Iron
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-598664
DO - https://doi.org/10.1007/s00216-024-05274-0
SN - 1618-2642
SP - 3117
EP - 3125
PB - Springer
CY - Berlin
AN - OPUS4-59866
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Yu, Jialu
A1 - Oelze, Marcus
A1 - Schannor, Mathias
A1 - Nordstad, Simon
A1 - Vogl, Jochen
T1 - New Potential Haematite and Magnetite Reference Materials for Iron Isotope Measurements by Solution Nebulisation MC ‐ ICP ‐ MS and by In Situ ns ‐ LA ‐ MC ‐ ICP ‐ MS
N2 - Iron isotope ratios of haematite (Fe2O3) and magnetite (Fe3O4) provide insights into geochemical, environmental and planetary processes. In most studies, Fe isotope measurements are commonly performed using solution nebulisation multi-collector inductively coupled plasma-mass spectrometry (SN-MC-ICP-MS). Nanosecond laser ablation multi-collector inductively coupled plasma-mass spectrometry (ns-LA-MC-ICP-MS) requires minimal sample preparation, and provides spatially resolved variation of iron isotopes at micro-scale. However, homogeneous and matrix-matched haematite/magnetite reference materials are lacking for precise in situ isotopic measurement. The iron isotope ratios of two potential reference materials resembling natural haematite (HMIE-NP-B01) and natural magnetite (MAKP-NP-B01) were characterised. Size fractions between 5–63 μm of the powdered Fe oxides were milled to nanoparticles, freeze-dried, homogenised, and pressed into pellets. The materials were then evaluated using SN-MC-ICP-MS and LA-MC-ICP-MS. Sample powders of the two materials were measured by SN-MC-ICPMS after sample digestion and column separation and pressed pellets were analysed directly via ns-LA-MC-ICP-MS. In both cases iron isotope delta values are reported relative to the certified reference material IRMM-014, used as the bracketing standard (calibrator). The solution measurements yielded δ56Fe values of -0.25 ± 0.08‰ (N = 13, 2s) for HMIE-NP-B01, and -0.05 ± 0.09‰ (N = 12, 2s) for MAKP-NP-B01, considered as the preferred Fe isotope delta values. In situ isotopic analysis via ns-LA-MC-ICP-MS yielded δ56Fe values of -0.28 ± 0.28‰ (N = 19, 2s) for HMIE-NP-B01 and -0.12 ± 0.24‰ (N = 22, 2s) for MAKP-NP-B01, consistent with the solution Fe isotope data. The homogeneity of Fe isotopes of the pellets was evaluated by ns-LA-MC-ICP-MS analyses of three different positions to further confirm that both materials are isotopically homogeneous. Both materials can be considered as potential quality control and bracketing reference materials for Fe isotopic measurements by in situ ns-LA-MC-ICP-MS analysis.
KW - Laser ablation
KW - Fe isotope
KW - Fe-oxides
PY - 2026
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654755
DO - https://doi.org/10.1111/ggr.70037
SN - 1639-4488
SP - 1
EP - 12
PB - John Wiley & Sons Ltd.
AN - OPUS4-65475
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zaki, Mohammad
A1 - Prinz, Carsten
A1 - Ruehle, Bastian
T1 - A Self-Driving Lab for Nano- and Advanced Materials Synthesis
N2 - The recent emergence of self-driving laboratories (SDL) and material acceleration platforms (MAPs) demonstrates the ability of these systems to change the way chemistry and material syntheses will be performed in the future. Especially in conjunction with nano- and advanced materials which are generally recognized for their great potential in solving current material science challenges, such systems can make disrupting contributions. Here, we describe in detail MINERVA, an SDL specifically built and designed for the synthesis, purification, and in line characterization of nano- and advanced materials. By fully automating these three process steps for seven different materials from five representative, completely different classes of nano- and advanced materials (metal, metal oxide, silica, metal organic framework, and core–shell particles) that follow different reaction mechanisms, we demonstrate the great versatility and flexibility of the platform. We further study the reproducibility and particle size distributions of these seven representative materials in depth and show the excellent performance of the platform when synthesizing these material classes. Lastly, we discuss the design considerations as well as the hardware and software components that went into building the platform and make all of the components publicly available.
KW - Self-driving laboratories
KW - Materials acceleration platforms
KW - Nanomaterials
KW - Advanced materials
KW - Automation
KW - Robotics
KW - In-line characterization
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-627361
DO - https://doi.org/10.1021/acsnano.4c17504
SN - 1936-086X
VL - 19
IS - 9
SP - 9029
EP - 9041
PB - ACS Publications
CY - Washington, DC
AN - OPUS4-62736
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zettner, Alina
A1 - Gojani, Ardian
A1 - Schmid, Thomas
A1 - Gornushkin, Igor B.
T1 - Evaluation of a Spatial Heterodyne Spectrometer for Raman Spectroscopy of Minerals
N2 - Spatial heterodyne spectroscopy (SHS) is a novel spectral analysis technique that is being applied for Raman spectroscopy of minerals. This paper presents the theoretical basis of SHS and its application for Raman measurements of calcite, quartz and forsterite in marble, copper ore and nickel ore, respectively. The SHS measurements are done using a broadband (518–686 nm) and resolving power R ≈ 3000 instrument. The spectra obtained using SHS are compared to those obtained by benchtop and modular dispersive spectrometers. It is found that SHRS performance in terms of resolution is comparable to that of the benchtop spectrometer and better than the modular dispersive spectrometer, while the sensitivity of SHRS is worse than that of a benchtop spectrometer, but better than that of a modular dispersive spectrometer. When considered that SHS components are small and can be packaged into a handheld device, there is interest in developing an SHS-based Instrument for mobile Raman spectroscopy. This paper evaluates the possibility of such an application.
KW - Forsterite
KW - Spatial heterodyne spectrometer
KW - Interferometric spectroscopy
KW - Fourier transform spectroscopy
KW - Raman spectroscopy
KW - Calcite
KW - Quartz
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-504624
DO - https://doi.org/10.3390/min10020202
VL - 10
IS - 2
SP - 202
PB - MDPI
CY - Basel, Switzerland
AN - OPUS4-50462
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zhang, Kun
A1 - Carrod, Andrew J.
A1 - Del Giorgio, Elena
A1 - Hughes, Joseph
A1 - Rurack, Knut
A1 - Bennet, Francesca
A1 - Hodoroaba, Vasile-Dan
A1 - Harrad, Stuart
A1 - Pikramenou, Zoe
T1 - Luminescence Lifetime-Based Sensing Platform Based on Cyclometalated Iridium(III) Complexes for the Detection of Perfluorooctanoic Acid in Aqueous Samples
N2 - Luminescence lifetimes are an attractive analytical method for detection due to its high sensitivity and stability. Iridium probes exhibit luminescence with long excited-state lifetimes, which are sensitive to the local environment. Perfluorooctanoic acid (PFOA) is listed as a chemical of high concern regarding its toxicity and is classified as a “forever chemical”. In addition to strict limits on the presence of PFOA in drinking water, environmental contamination from industrial effluent or chemical spills requires rapid, simple, accurate, and cost-effective analysis in order to aid containment. Herein, we report the fabrication and function of a novel and facile luminescence sensor for PFOA based on iridium modified on gold surfaces. These surfaces were modified with lipophilic iridium complexes bearing alkyl chains, namely, IrC6 and IrC12, and Zonyl-FSA surfactant. Upon addition of PFOA, the modified surfaces IrC6-FSA@Au and IrC12-FSA @Au show the largest change in the red luminescence signal with changes in the luminescence lifetime that allow monitoring of PFOA concentrations in aqueous solutions. The platform was tested for the measurement of PFOA in aqueous samples spiked with known concentrations of PFOA and demonstrated the capacity to determine PFOA at concentrations >100 μg/L (240 nM).
KW - Perfluorooctanoic Acid (PFOA)
KW - Cyclometalated iridium (III) complexes
KW - Luminescent lifetime
KW - Optically active surfaces
KW - ToF-SIMS
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-594535
UR - https://pubs.acs.org/doi/10.1021/acs.analchem.3c04289
DO - https://doi.org/10.1021/acs.analchem.3c04289
VL - 96
IS - 4
SP - 1565
EP - 1575
PB - American Chemical Society (ACS)
AN - OPUS4-59453
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zhuang, Y.
A1 - Spahr, S.
A1 - Lutze, H.V.
A1 - Reith, C.J.
A1 - Hagemann, N.
A1 - Paul, Andrea
A1 - Haderlein, S.B.
T1 - Persulfate activation by biochar and iron: Effect of chloride on formation of reactive species and transformation of N,N-diethyl-m-toluamide (DEET)
N2 - Fenton-like processes using persulfate for oxidative water treatment and contaminant removal can be enhanced by the addition of redox-active biochar, which accelerates the reduction of Fe(III) to Fe(II) and increases the yield of reactive species that react with organic contaminants. However, available data on the formation of non-radical or radical species in the biochar/Fe(III)/persulfate system are inconsistent, which limits the evaluation of treatment efficiency and applicability in different water matrices. Based on competition kinetics calculations, we employed different scavengers and probe compounds to systematically evaluate the effect of chloride in presence of organic matter on the formation of major reactive species in the biochar/Fe(III)/persulfate system for the transformation of the model compound N,N‑diethyl-m-toluamide (DEET) at pH 2.5. We show that the transformation of methyl phenyl sulfoxide (PMSO) to methyl phenyl sulfone (PMSO2) cannot serve as a reliable indicator for Fe(IV), as previously suggested, because sulfate radicals also induce PMSO2 formation. Although the formation of Fe(IV) cannot be completely excluded, sulfate radicals were identified as the major reactive species in the biochar/Fe(III)/persulfate system in pure water. In the presence of dissolved organic matter, low chloride concentrations (0.1 mM) shifted the major reactive species likely to hydroxyl radicals. Higher chloride concentrations (1 mM), as present in a mining-impacted acidic surface water, resulted in the formation of another reactive species, possibly Cl2•−, and efficient DEET degradation. To tailor the application of this oxidation process, the water matrix must be considered as a decisive factor for reactive species formation and contaminant removal.
KW - Water treatment
KW - Organic contaminants
KW - Fenton-like systems
KW - Radicals
KW - ESR
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-608677
DO - https://doi.org/10.1016/j.watres.2024.122267
SN - 0043-1354
VL - 265
SP - 1
EP - 8
PB - Elsevier Ltd.
AN - OPUS4-60867
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zhuang, Yiling
A1 - Haderlein, Stefan B.
A1 - Hagemann, Nikolas
A1 - Grafmüller, Jannis
A1 - Gogler, Karolin
A1 - Paul, Andrea
A1 - Fink, Friedrich
A1 - Spahr, Stephanie
T1 - Activation of persulfate by biochar and iron: role of biochar pyrolysis conditions and ash amendments
N2 - Redox-active biochars can enhance contaminant transformation in persulfate-based Fenton-like water treatment by facilitating Fe(III) reduction to Fe(II). However, biochar properties vary greatly depending on both feedstock selection and pyrolysis conditions. Best suited biochars for Fe(III) reduction and persulfate activation have yet to be identified. Here, we investigated eight biochars for their ability to activate persulfate with Fe(III) to transform N,N-diethyl-m-toluamide (DEET) in water. Four of the biochars were produced from beech wood under different pyrolysis conditions (450–750 °C, high and low nitrogen flow rate in the reactor) and four biochars were produced from softwood amended with 0 – 43 weight percent (wt%) wood ash prior to pyrolysis at 500 °C. Beech wood biochar produced at 450 °C transformed DEET most efficiently with a half-life time of 39 ± 4 min, likely due to the high concentration of surface oxygen functional groups and persistent free radicals that accelerated Fe(III) reduction and formation of reactive species. Among the ash-amended biochars, biochar with 16 wt% ash amendment showed the most efficient DEET transformation with a half-life time of 27 ± 0.6 min, which is 10-times faster compared to a non-ash-amended biochar produced from the same biomass under similar pyrolysis conditions. Ash amendment led to the formation of crystalline iron minerals in biochars, which likely promoted Fe(III) reduction and persulfate activation. Our results highlight the potential for fine-tuning the redox properties of biochar, e.g., by ash amendment to a woody feedstock, enabling tailored performance for specific water treatment applications.
KW - Persistent free radicals
KW - Redox-active moieties
KW - Fenton-like systems
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-634504
DO - https://doi.org/10.1016/j.seppur.2025.133634
SN - 1383-5866
VL - 374
SP - 1
EP - 8
PB - Elsevier B.V.
AN - OPUS4-63450
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Ziegler, K.
A1 - Kunert, A. T.
A1 - Reinmuth-Selzle, K.
A1 - Leifke, A. L.
A1 - Widera, D.
A1 - Weller, Michael G.
A1 - Schuppan, D.
A1 - Fröhlich-Nowoisky, J.
A1 - Lucas, K.
A1 - Pöschl, U.
T1 - Chemical modification of pro-inflammatory proteins by peroxynitrite increases activation of TLR4 and NF-κB: Implications for the health effects of air pollution and oxidative stress
N2 - Environmental pollutants like fine particulate matter can cause adverse health effects through oxidative stress and inflammation. Reactive oxygen and nitrogen species (ROS/RNS) such as peroxynitrite can chemically modify proteins, but the effects of such modifications on the immune system and human health are not well understood. In the course of inflammatory processes, the Toll-like receptor 4 (TLR4) can sense damage-associated molecular patterns (DAMPs). Here, we investigate how the TLR4 response and pro-inflammatory potential of the proteinous DAMPs α-Synuclein (α-Syn), heat shock protein 60 (HSP60), and high-mobility-group box 1 protein (HMGB1), which are relevant in neurodegenerative and cardiovascular diseases, changes upon chemical modification with peroxynitrite.
For the peroxynitrite-modified proteins, we found a strongly enhanced activation of TLR4 and the pro-inflammatory transcription factor NF-κB in stable reporter cell lines as well as increased mRNA expression and secretion of the pro-inflammatory cytokines TNF-α, IL-1β, and IL-8 in human monocytes (THP-1). This enhanced activation of innate immunity via TLR4 is mediated by covalent chemical modifications of the studied DAMPs.
Our results show that proteinous DAMPs modified by peroxynitrite more potently amplify inflammation via TLR4 activation than the native DAMPs, and provide first evidence that such modifications can directly enhance innate immune responses via a defined receptor. These findings suggest that environmental pollutants and related ROS/RNS may play a role in promoting acute and chronic inflammatory disorders by structurally modifying the body's own DAMPs. This may have important consequences for chronic neurodegenerative, cardiovascular or gastrointestinal diseases that are prevalent in modern societies, and calls for action, to improve air quality and climate in the Anthropocene.
KW - Protein nitration
KW - Protein oligomerization
KW - Damage-associated molecular patterns (DAMPs)
KW - Pattern recognition receptor
KW - Anthropocene
KW - Environmental pollutants
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-517128
DO - https://doi.org/10.1016/j.redox.2020.101581
VL - 37
SP - 101581
PB - Elsevier B.V.
AN - OPUS4-51712
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zimmermann, T.
A1 - von der Au, Marcus
A1 - Reese, A.
A1 - Klein, O.
A1 - Hildebrandt, L.
A1 - Pröfrock, D.
T1 - Substituting HF by HBF4 – an optimized digestion method for multi-elemental sediment analysis via ICP-MS/MS
N2 - Determination of elemental mass fractions in sediments plays a major role in evaluating the environmental status of aquatic ecosystems. Herewith, the optimization of a new total digestion protocol and the subsequent analysis of 48 elements in different sediment reference materials (NIST SRM 2702, GBW 07313, GBW 07311 and JMC-2) based on ICP-MS/MS detection is presented. The developed method applies microwave acid digestion and utilizes HBF4 as fluoride source for silicate decomposition. Similar to established protocols based on HF, HBF4 ensures the dissolution of the silicate matrix, as well as other refractory oxides. As HBF4 is not acutely toxic; no special precautions have to be made and digests can be directly measured via ICP-MS without specific sample inlet systems, evaporation steps or the addition of e.g. H3BO3, in order to mask excess HF. Different acid mixtures with and without HBF4 were evaluated in terms of digestion efficiency based on the trace metal recovery. The optimized protocol (5 mL HNO3, 2 mL HCL, 1 mL HBF4) allows a complete dissolution of the analyzed reference materials, as well as quantitative recoveries for a wide variety of certified analytes. Low recoveries for e.g. Sr, Ba and rare earth elements due to fluoride precipitation of HF-based digestions protocols, can be avoided by the usage of HBF4 instead. Based on the usage of high purity HBF4 all relevant trace, as well as matrix elements can be analyzed with sufficiently low LOQs (0.002 μg L−1 for U up to 6.7 μg L−1 for Al). In total, 34 elements were within a recovery range of 80%–120% for all three analyzed reference materials GBW 07313, GBW 07311 and JMC-2. 14 elements were outside a recovery range of 80%–120% for at least one of the analyzed reference materials.
KW - Reference Materials
KW - Sediment
KW - HF free Digestion
PY - 2020
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-510480
DO - https://doi.org/10.1039/D0AY01049A
SP - 1
EP - 10
PB - Royal Society of Chemistry
AN - OPUS4-51048
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zweigle, J.
A1 - Schmidt, A.
A1 - Bugsel, B.
A1 - Vogel, Christian
A1 - Simon, Fabian
A1 - Zwiener, C.
T1 - Perfluoroalkyl acid precursor or weakly fluorinated organic compound? A proof of concept for oxidative fractionation of PFAS and organofluorines
N2 - Organofluorine mass balance approaches are increasingly applied to investigate the occurrence of per- and polyfluoroalkyl substances (PFAS) and other organofluorines in environmental samples more comprehensively. Usually, complex samples prevent the identification and quantification of every fluorine-containing molecule. Consequently, large unidentified fractions between fluorine sum parameters such as extractable organic fluorine (EOF) and the sum of quantified analytes are frequently reported. We propose using oxidative conversion to separate (unidentified) weakly fluorinated compounds (e.g., pesticides, pharmaceuticals) from PFAA-precursors (perfluoroalkyl chain lengths ≥ C6). We show with three organofluorine model substances (flufenamic acid, diflufenican, pantoprazole) that CF3-groups or aromatic fluorine can be quantitatively converted to inorganic fluoride and trifluoroacetic acid (TFA) by applying PhotoTOP oxidation (UV/TiO2). The principle of fluorine separation in mixtures is demonstrated by the oxidation of the three weakly fluorinated compounds together with the PFAA-precursor 6:2/6:2 fluorotelomer mercaptoalkyl phosphate diester (FTMAP). After oxidation, the products F− and TFA were separated from PFCAs ( C4) by SPE, and the fractions were analyzed individually. Closed mass balances both with and without the addition of organic matrix were achieved. Eventually, the fluorine balance was verified by total fluorine measurements with combustion ion chromatography (CIC). The proposed methods should be considered a proof of concept to potentially explain unidentified fractions of the EOF, especially if compounds with low fluorine content such as pesticides, pharmaceuticals, and their transformation products contribute largely to the EOF. Future studies are needed to show the applicability to the complexity of environmental samples.
Graphical Abstract
KW - Combustion Ion Chromatography
KW - Per- and Polyfluoroalkyl substances (PFAS)
PY - 2024
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-613429
DO - https://doi.org/10.1007/s00216-024-05590-5
SP - 1
EP - 10
PB - Springer Science and Business Media LLC
AN - OPUS4-61342
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zänker, Steffen
A1 - Scholz, G.
A1 - Marquardt, Julien
A1 - Emmerling, Franziska
T1 - Structural changes in Ba-compounds of different hardness induced by high-energy ball milling – evidenced by 137Ba NMR and X-ray powder diffraction
N2 - Changes in the global bulk and local structures, of three different barium compounds (BaZrO3, BaF2, and BaFCl),were induced by mechanical milling and followed using X-ray powder diffraction (PXRD), subsequent microstructure analysis, and 137Ba solid state NMR spectroscopy. Harder materials like BaZrO3 experience significantly higher structural changes upon milling than softer materials like BaF2. Moreover, soft materials with layered structures, like BaFCl, show a pronounced structural change during the milling process. By combining PXRD and solid state NMR, detailed information on the changes to the global and local structures were obtained, which are of interest for mechanochemical synthesis, mechanically treated catalysts or ionic conductors.
KW - Mechanochemistry
KW - X-ray diffraction
KW - Solid state NMR
PY - 2022
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-547397
DO - https://doi.org/10.1002/zaac.202200026
SN - 0044-2313
VL - 648
IS - 10
SP - 1
EP - 8
PB - Wiley-VCH
CY - Weinheim
AN - OPUS4-54739
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -
TY - JOUR
A1 - Zöllner, Moritz T.
A1 - Dariz, Petra
A1 - Riedel, Jens
A1 - Schmid, Thomas
T1 - Dolomite and Mg Calcite as Mineral Thermometers in Mortar Binders. A High Resolution Raman Spectroscopic Study
N2 - This paper suggests the use of high‐resolution Raman scattering bands of MgCa carbonates as posteriori thermometer minerals in archaeometric studies. Therefore, the thermal behavior of two dolomite samples and the hydration and carbonation reaction in air of the decomposition products were investigated by Raman microspectroscopy. The increase in the calcination temperature resulted in the formation of – Raman silent MgO and – inert Mg calcite at 700°C–750°C. In contrast, the decarbonation, hydration, and recarbonation of sample material exposed to 750°C–900°C in a muffle furnace led to the appearance of Mg‐free calcite. High spectral resolution Raman spectroscopy enabled a spectral distinction between these two groups due to differences in the band parameters (peak position, bandwidth) of the vibrational (v1, v4, L) modes of calcite. In combination with Raman microspectroscopic mapping, this spectral information represents a new approach for the estimation of burning temperatures of medieval high‐fired gypsum mortars via natural dolomite impurities. Thus, the results of this work highlight the importance and potential of Raman microspectroscopy as a thermometric tool for elucidating the thermal history of anthropogenic fired materials, with potential applications for archaeometry and art technology, as well as for quality controls in the frame of the production of mineral mortar binders and ceramics or bricks, respectively.
KW - Mineral thermometry
KW - Raman spectroscopy
KW - Dolomite
KW - High-fired gypsum mortar
PY - 2025
UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-630270
DO - https://doi.org/10.1002/jrs.6810
SN - 1097-4555
SP - 1
EP - 13
PB - Wiley
AN - OPUS4-63027
LA - eng
AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany
ER -