TY - JOUR A1 - Martusevich, A. A1 - Kornev, R. A1 - Ermakov, A. A1 - Gornushkin, Igor B. A1 - Nazarov, V. A1 - Shabarova, L. A1 - Shkrunin, V. T1 - Spectroscopy of Laser-Induced Dielectric Breakdown Plasma in Mixtures of Air with Inert Gases Ar, He, Kr, and Xe N2 - The generation of ozone and nitrogen oxides by laser-induced dielectric breakdown (LIDB) in mixtures of air with noble gases Ar, He, Kr, and Xe is investigated using OES and IR spectroscopy, mass spectrometry, and absorption spectrophotometry. It is shown that the formation of NO and NO2 noticeably depends on the type of inert gas; the more complex electronic configuration and the lower ionization potential of the inert gas led to increased production of NO and NO2. The formation of ozone occurs mainly due to the photolytic reaction outside the gas discharge zone. Equilibrium thermodynamic analysis showed that the formation of NO in mixtures of air with inert gases does not depend on the choice of an inert gas, while the equilibrium concentration of the NO+ ion decreases with increasing complexity of the electronic configuration of an inert gas. KW - Laser-induced dielectric breakdown (LIDB) KW - Nitrogen monoxide KW - Nitrogen dioxide KW - Ozone KW - Emission spectroscopy KW - Inert gases KW - Thermodynamic analysis PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-568258 DO - https://doi.org/10.3390/s23020932 SN - 1424-8220 VL - 23 IS - 2 SP - 1 EP - 13 PB - MDPI CY - Basel, Switzerland AN - OPUS4-56825 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Matiushkina, Anna A1 - Abram, Sarah-Luise A1 - Tavernaro, Isabella A1 - Richstein, R. A1 - Reithofer, M. R. A1 - Andresen, Elina A1 - Michaelis, Matthias A1 - Koch, Matthias A1 - Resch-Genger, Ute T1 - Quantifying Citrate Surface Ligands on Iron Oxide Nanoparticles with TGA, CHN Analysis, NMR, and RP-HPLC with UV Detection N2 - Although citrate is frequently used as a surface ligand for nanomaterials (NMs) such as metal, metal oxide, and lanthanide-based NMs in hydrophilic environments due to its biocompatibility and simple replacement by other more strongly binding ligands in postsynthetic surface modification reactions, its quantification on NM surfaces has rarely been addressed. Here, we present a multimethod approach for citrate quantification on iron oxide nanoparticles (IONPs) broadly applied in the life and material sciences. Methods explored include thermogravimetric (TGA) and elemental (CHN) analysis, providing citrate-nonspecific information on the IONP coating, simple photometry, and citrate-selective reversed-phase high-performance liquid chromatography (RP-HPLC) with absorption (UV) detection and quantitative nuclear magnetic resonance spectroscopy (qNMR). Challenges originating from the strongly absorbing magnetic NM and paramagnetic iron species interfering with optical and NMR Methods were overcome by suitable sample preparation workflows. Our multimethod approach to citrate quantification highlights the advantages of combining specific and unspecific methods for characterizing NM Surface chemistry and method cross-validation. It also demonstrates that chemically nonselective measurements can favor an overestimation of the amount of a specific surface ligand by signal contributions from molecules remaining on the NM surface, e.g., from particle synthesis, such as initially employed ligands and/or surfactants. Our results emphasize the potential of underexplored selective RPHPLC for quantifying ligands on NMs, which does not require a multistep sample preparation workflow such as qNMR for many NMs and provides a higher sensitivity. These findings can pave the road to future applications of versatile HPLC methods in NM characterization. KW - Advanced material KW - Functional group KW - Iron oxide KW - Ligand KW - Nano KW - Particle KW - Quantification KW - Surface analysis PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-648632 DO - https://doi.org/10.1021/acs.analchem.5c03024 SN - 0003-2700 VL - 97 IS - 36 SP - 19627 EP - 19634 PB - American Chemical Society (ACS) CY - Washington, DC AN - OPUS4-64863 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Matschat, Ralf A1 - Richter, Silke A1 - Vogl, Jochen A1 - Kipphardt, Heinrich T1 - On the way to SI traceable primary transfer standards for amount of substance measurements in inorganic chemical analysis N2 - During its 25 years of existence, the Inorganic Analysis Working Group of the Consultative Committee for Amount of Substance: Metrology in Chemistry and Biology (CCQM IAWG) has achieved much in establishing comparability of measurement results. Impressive work has been done on comparison exercises related to real-world problems in fields such as ecology, food, or health. In more recent attempts, measurements and comparisons were focused on calibration solutions which are the basis of most inorganic chemical measurements. This contribution deals with the question of how to achieve full and transparent SI traceability for the values carried by such solutions. Within this framework, the use of classical primary methods (CPMs) is compared to the use of a primary difference method (PDM). PDM is a method with a dual character, namely a metrological method with a primary character, based on the bundling of many measurement methods for individual impurities, which lead to materials with certified content of the main component. As in classical methods, where small corrections for interferences are accepted, in PDM, many small corrections are bundled. In contrast to classical methods, the PDM is universally applicable to all elements in principle. Both approaches can be used to certify the purity (expressed as mass fraction of the main element) of a high-purity material. This is where the metrological need of National Metrology Institutes (NMIs) for analytical methods meet the challenges of analytical methods. In terms of methods, glow discharge mass spectrometry (GMDS) with sufficient uncertainties for sufficiently small impurity contents is particularly noteworthy for the certification of primary transfer standards (PTS), and isotope dilution mass spectrometry (IDMS), which particularly benefits from PTS (back-spikes) with small uncertainties, is particularly noteworthy for the application. The corresponding relative uncertainty which can be achieved using the PDM is very low (< 10−4). Acting as PTS, they represent the link between the material aspect of the primary calibration solutions and the immaterial world of the International System of Units (SI). The underlying concepts are discussed, the current status of implementation is summarised, and a roadmap of the necessary future activities in inorganic analytical chemistry is sketched. It has to be noted that smaller measurement uncertainties of the purity of high-purity materials not only have a positive effect on chemical measurements, but also trigger new developments and findings in other disciplines such as thermometry or materials science. KW - Inorganic chemical analysis KW - Primary transfer standards (PTSs) KW - Traceability KW - Classical primary measurement method (CPM) KW - Primary difference measurement method (PDM) KW - Metrology in chemistry PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-572743 DO - https://doi.org/10.1007/s00216-023-04660-4 SN - 1618-2642 SN - 1618-2650 VL - 415 SP - 3057 EP - 3071 PB - Springer CY - Berlin AN - OPUS4-57274 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - McGonigle, Rebecca A1 - Glasgow, Jodie A1 - Houston, Catriona A1 - Cameron, Iain A1 - Homann, Christian A1 - Black, Dominic J. A1 - Pal, Robert A1 - MacKenzie, Lewis E. ED - MacKenzie, Lewis E. T1 - Autoclave reactor synthesis of upconversion nanoparticles, unreported variables, and safety considerations N2 - Autoclave reactors are widely used across chemical and biological sciences, including for the synthesis of upconversion nanoparticles (UCNPs) and other nanomaterials. Yet, the details of how autoclave reactors are used in such synthesis are rarely reported in the literature, leaving several key synthesis variables widely unreported and thereby hampering experimental reproducibility. In this perspective, we discuss the safety considerations of autoclave reactors and note that autoclaves should only be used if they are (a) purchased from reputable suppliers/manufacturers and (b) have been certified compliant with relevant safety standards. Ultimately, using unsuitable autoclave equipment can pose a severe physical hazard and may breach legal safety requirements. In addition, we highlight several parameters in autoclave synthesis that should be reported as standard to maximise the reproducibility of autoclave synthesis experiments across materials and chemistry research. We encourage users of autoclave synthesis vessels to: (1) adopt high-safety autoclaves and (2) report the many experimental variables involved to enhance experimental reproducibility. KW - Reference material KW - Nano KW - Particle KW - Shell KW - Fluorescence KW - Lifetime KW - Decay kinetics KW - Synthesis KW - Quality assurance KW - Method KW - Energy transfer KW - Upconversion KW - Autoclave synthesis KW - Data comparability PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-625672 DO - https://doi.org/10.1038/s42004-025-01415-3 VL - 8 IS - 1 SP - 1 EP - 7 PB - Springer Science and Business Media LLC AN - OPUS4-62567 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Meiers, Emelie A1 - Scholl, Juliane A1 - Droas, Morten A1 - Vogel, Christian A1 - Leube, Peter A1 - Sommerfeld, Thomas A1 - Bagheri, A. A1 - Adam, Christian A1 - Seubert, A. A1 - Koch, Matthias T1 - Development and evaluation of analytical strategies for the monitoring of per- and polyfluoroalkyl substances from lithium-ion battery recycling materials N2 - Per- and polyfluoroalkyl substances (PFAS) are well-known as “forever chemicals” and persistent pollutants released by different anthropogenic sources. The potential release of PFAS from accumulating electronic waste and lithium-ion battery (LIB) recycling activities has gained increasing attention in the past years. This creates a need for analytical methods tailored for the determination of PFAS out of environmental matrices related to the named activities or directly out of the concerned materials. In this work, analytical strategies for the monitoring of PFAS in LIB recycling materials were explored for a group of legacy perfluoro sulfonic- and carbonic acids (PFSA and PFCA) and of fluorinated sulfonylimides suspected to be LIB electrolyte ingredients. These analytical strategies comprehend PFAS target approaches with a herein optimized liquid chromatography tandem mass spectrometry (LC–MS/MS) method equipped with a HILIC (hydrophilic interaction liquid chromatography) column in combination with the TOP (total oxidizable precursor) assay and an adapted sample preparation method for high-matrix LIB recycling materials. The validated target method was applied to a set of LIB recycling materials: end-of-life batteries, black masses from hydrometallurgical recycling, and gas absorption solutions from thermal treatment of black masses as part of the recycling procedure. Investigation results show that the LIB industry can be connected to the release of both “LIB”-PFAS, such as the target sulfonylimides, and “already-legacy” PFAS, like the PFSA and PFCA. Especially, the presence of trifluoroacetic acid (TFA) as an emerging pollutant in every investigated LIB material type underlines the threat of PFAS emissions from LIB waste and recycling activities. KW - Per- and polyfluoroalkyl substances (PFAS) KW - Battery PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-647015 DO - https://doi.org/10.1007/s00216-025-06165-8 SN - 1618-2642 VL - 417 SP - 6567 EP - 6583 PB - Springer Science and Business Media LLC AN - OPUS4-64701 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Menero-Valdés, P. A1 - Chronakis, Michail Ioannis A1 - Fernández, B. A1 - Quarles Jr., C. D. A1 - González-Iglesias, H. A1 - Meermann, Björn A1 - Pereiro, R. T1 - Single Cell–ICP–ToF-MS for the Multiplexed Determination of Proteins: Evaluation of the Cellular Stress Response N2 - An automated and straightforward detection and data treatment strategy for the determination of the protein relative concentration in individual human cells by single cell–inductively coupled plasma–time-of-flight mass spectrometry (sc-ICP-ToF-MS) is proposed. Metal nanocluster (NC)-labeled specific antibodies for the target proteins were employed, and ruthenium red (RR) staining, which binds to the cells surface, was used to determine the number of cell events as well as to evaluate the relative volume of the cells. As a proof of concept, the expression of hepcidin, metallothionein-2, and ferroportin employing specific antibodies labeled with IrNCs, PtNCs, and AuNCs, respectively, was investigated by sc-ICP-ToF-MS in human ARPE-19 cells. Taking into account that ARPE-19 cells are spherical in suspension and RR binds to the surface of the cells, the Ru intensity was related to the cell volume (i.e., the cell volume is directly proportional to (Ru intensity)3/2), making it possible to determine not only the mass of the target proteins in each individual cell but also the relative concentration. The proposed approach is of particular interest in comparing cell cultures subjected to different supplementations. ARPE-19 cell cultures under two stress conditions were compared: a hyperglycemic model and an oxidative stress model. The comparison of the control with treated cells shows not only the mass of analyzed species but also the relative changes in the cell volume and concentration of target proteins, clearly allowing the identification of subpopulations under the respective treatment. KW - Peptides and Proteins KW - Immunology KW - Metals PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-581630 DO - https://doi.org/10.1021/acs.analchem.3c02558 VL - 95 IS - 35 SP - 13322 EP - 13329 PB - ACS Publications AN - OPUS4-58163 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mervič, Kristina A1 - Azimzada, Agil A1 - Bayat, Mehmet Emin A1 - Šala, Martin A1 - Meermann, Björn T1 - CO2-based matrix-independent carbon quantification approach for single microplastic-ICP-MS analysis N2 - This study presents a new CO2-based, matrix-independent calibration approach for size determination of microplastic (MP) particles using single particle inductively coupled plasma-mass spectrometry (sp-ICP-MS). By incorporating a CO2 gas calibration approach and upon adjusting the flow rates, an accurate size determination of MPs between 2 and 7 μm was enabled. Scanning electron microscopy (SEM) was successfully applied for method validation. The CO2 gas calibration curves exhibited excellent linearity and reproducibility, with minimal matrix effects across different sample types and matrices, including river water and saline solutions. This CO2-based approach eliminates the limitations of matrix- and size-dependent calibrations, enabling robust and accurate size determinations of MPs. This advancement represents a significant step forward in the analytical capabilities for MPs, paving the way for improved environmental monitoring and assessment of plastic pollution. KW - sp-ICP-MS KW - Microplastic KW - New calibration strategy PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-633049 DO - https://doi.org/10.1007/s00216-025-05934-9 SN - 1618-2642 SP - 1 EP - 11 PB - Springer CY - Berlin AN - OPUS4-63304 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Michail Ioannis, Chronakis A1 - von der Au, Marcus A1 - Meermann, Björn T1 - Single cell-asymmetrical flow field-flow fractionation/ICP-time of flight-mass spectrometry (sc-AF4/ICP-ToF-MS): an efficient alternative for the cleaning and multielemental analysis of individual cells N2 - Asymmetrical Flow Field-Flow Fractionation (AF4), as a cleaning technique, was combined on-line with the multielemental analytical capabilities of an Inductively Coupled Plasma-Time of Flight-Mass Spectrometer (ICP-ToF-MS). In that manner, the heavy ionic matrix effect of untreated cells' samples can be significantly reduced. As a proof of concept, commercial baker's yeast cells were analysed. KW - AF4 KW - Single Cell KW - Cleaning PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-576419 DO - https://doi.org/10.1039/d2ja00264g SN - 0267-9477 VL - 37 IS - 12 SP - 2691 EP - 2700 PB - Royal Society of Chemistry AN - OPUS4-57641 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Michalska, Karina A1 - Heiermann, Monika A1 - Lühr, Carsten A1 - Meermann, Björn A1 - Pecenka, Ralf A1 - Schulz, Andreas A1 - Langhammer, Nicole A1 - Theuerl, Susanne A1 - Prochnow, Annette T1 - Potentials of typical plant species from rewetted fenlands for the supply of strategic elements N2 - Rewetting of peatlands requires the development of new biomass utilization pathways. The supply of strategic elements with key importance for the development of priority technologies, such as germanium (Ge), silicon (Si) and rare earth elements, from fenland plants is one option. To provide a first estimation of the potential, concentrations of strategic elements were determined in nine biomass samples covering typical fenland vegetation in northeast Germany. Subsequently, a simplified estimation of potential revenue from strategic element recovery was made. The analysed plant species can be classified as high or intermediate Si plant accumulators with highest contents of more than 16.0 g Si kg−1 dry mass (DM) in sedges and common reeds. Ge concentrations were lower with reed canary grass containing the highest amounts of 465.3 µg Ge kg−1 DM. Simultaneous acquisition of Ge and Si could provide higher total element yields and revenues of up to 500 $ ha−1. In contrast, the potentials for supplying rare earth elements appeared to be very low, with common reed containing the highest sum of rare earth elements of 437.4 µg kg−1 DM. Biomass from rewetted fenlands is capable of accumulating strategic elements. More knowledge is required to understand the factors affecting their accumulation. KW - Recycling KW - Fenlands KW - Strategic elements PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-635631 DO - https://doi.org/10.1038/s41598-025-05180-0 SN - 2045-2322 VL - 15 IS - 1 SP - 1 EP - 14 PB - Springer Science and Business Media LLC AN - OPUS4-63563 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Miliūtė, Aistė A1 - Bustamante, Joana A1 - Karafiludis, Stephanos A1 - Zöllner, Moritz A1 - Eddah, Mustapha A1 - Emmerling, Franziska A1 - Mieller, Björn A1 - George, Janine A1 - Stawski, Tomasz M. T1 - Synthesis and phase purity of the negative thermal expansion material ZrV2O7 N2 - Synthesis of pure, homogeneous, and reproducible materials is key for the comprehensive understanding, design, and tailoring of material properties. In this study, we focus on the synthesis of ZrV2O7, a material known for its negative thermal expansion properties. We investigate the influence of solid-state and wet chemistry synthesis methods on the purity and homogeneity of ZrV2O7 samples. Our findings indicate that different synthesis methods significantly impact the material's characteristics. The solid-state reaction provided high-purity material through extended milling time and repeated calcination cycles, while the sol-gel reaction enabled a “near-atomic” level of mixing and, therefore, homogenous phase-pure ZrV2O7. We confirmed purity via X-ray diffraction and Raman spectroscopy, highlighting differences between phase-pure and multiphase ceramics. These analytical techniques allowed us to distinguish subtle differences in the structure of the material. Based on ab initio simulated phonon data, we were able to interpret the Raman spectra and visualise Raman active atom vibrations. We show that phase purity enables the unbiased characterisation of material properties such as negative thermal expansion. KW - NTE KW - Sol-gel KW - Solid-state KW - Ab-initio KW - XRD KW - Raman PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-624013 DO - https://doi.org/10.1039/d4tc04095c SN - 2050-7534 SP - 1 EP - 13 PB - Royal Society of Chemistry (RSC) AN - OPUS4-62401 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mohammad, W. A1 - Wegner, Karl David A1 - Comby-Zerbino, C. A1 - Trouillet, V. A1 - Ogayer, M. P. A1 - Coll, J.-L. A1 - Marin, R. A1 - Jaque Garcia, D. A1 - Resch-Genger, Ute A1 - Antoine, R. A1 - Le Guevel, X. T1 - Enhanced brightness of ultra-small gold nanoparticles in the second biological window through thiol ligand shell control N2 - Gold-based nanoparticles below 2 nm in size are promising as luminescent probes for in vivo bioimaging, owing to their brightness and rapid renal clearance. However, their use as contrast agents in the near-infrared II (NIR-II, 1000–1700 nm) range remains challenging due to their low photoluminescence (PL) quantum yield. To address this, PL enhancement can be achieved by either rigidifying the ligand-shell structure or increasing the size of the ligand shell. In this study, we synthesized ultra-small gold nanoparticles stabilized by co-ligands, namely monothiol and short dithiol molecules. By precisely controlling the amount of reducing agent used during particle preparation, we successfully modulated the physicochemical properties of the co-ligand shell, including its size, composition, and structure. Consequently, we achieved a remarkable 60-fold increase in the absorption cross-section at 990 nm while maintaining the small size of the 1.5-nm metal core. The analytical and optical characterization of our thiol-capped gold nanoparticles indicates that the ligand shell size is governed by the quantity of the reducing agent, which, in turn, impacts the balance between radiative and non-radiative processes, thereby influencing the PL quantum yield. KW - Gold nanocluster KW - NIR-II fluorescence KW - SWIR KW - Nanomaterial design KW - Calibrated fluorescence measurements PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-588117 DO - https://doi.org/10.1039/D3TC03021K SN - 2050-7526 VL - 11 IS - 42 SP - 14714 EP - 14724 PB - Royal Society of Chemistry (RSC) AN - OPUS4-58811 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mohan, M. A1 - Prochazka, D. A1 - You, Yi A1 - Riedel, Jens A1 - Gornushkin, Igor A1 - Rocnakova, I. A1 - Papula, M. A1 - Porízka, P. A1 - Kaizer, J. T1 - Investigating plasma morphology at material boundaries under varying ambient pressures N2 - Laser-Induced Breakdown Spectroscopy (LIBS) is a widely used technique for elemental analysis. The analysis of the obtained LIBS spectra generally assumes plasma homogeneity. However, using focused laser beams for interrogation, LIBS probes materials on the microscale and is, thus, prone to artefacts from sample heterogeneities on the micrometer scale. An ablation at a material boundary of two matrices may result in a significant inhomogeneity in the plasma plume, which can severely impact the accuracy of quantitative analysis. Since this propagation of the surface morphology into the plasma plume is driven by the plasma expansion, its final impact is strongly pressure dependent. This study examines the influence of varying ambient pressures (7–1000 mbar) on plasma morphology, spectral characteristics, and key plasma properties such as electron number density at a well-defined Cu–Sn boundary, in comparison with the results obtained using homogeneous alloys. Several approaches of plasma imaging with bandpass filters, spectroscopy, and Radon transform-based 3D reconstruction were employed to analyze elemental distribution, signal-to-noise (SNR) and signal-to-background (SBR) ratios, as well as electron number densities. The 3D reconstructions revealed a pronounced plasma asymmetry for the ablation at the material boundary, in contrast to the near-axial symmetry observed for the ablation of homogeneous alloys. At lower pressures, this distinct elemental separation in plasma persisted, while higher pressures led to an increased collisional mixing and homogenization. SNR and SBR were consistently lower for ablation at the boundary compared to homogeneous samples. These findings highlight how boundary ablation contributes to plasma inhomogeneities in LIBS analysis of heterogeneous materials and emphasize the need to account for these effects when using LIBS for elemental mapping of fine heterogeneous structures. KW - Laser-induced breakdown spectroscopy KW - Plasma inhomogeneity KW - Plasma tomography KW - Radon transform KW - Material boundaries KW - Ambient pressure effects PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-634777 DO - https://doi.org/10.1016/j.talanta.2025.128377 SN - 1873-3573 VL - 295 SP - 1 EP - 8 PB - Elsevier B.V. AN - OPUS4-63477 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mohr, Gunther A1 - Sommer, Konstantin A1 - Knobloch, Tim A1 - Altenburg, Simon A1 - Recknagel, Sebastian A1 - Bettge, Dirk A1 - Hilgenberg, Kai T1 - Process Induced Preheating in Laser Powder Bed Fusion Monitored by Thermography and Its Influence on the Microstructure of 316L Stainless Steel Parts N2 - Undetected and undesired microstructural variations in components produced by laser powder bed fusion are a major challenge, especially for safety-critical components. In this study, an in-depth analysis of the microstructural features of 316L specimens produced by laser powder bed fusion at different levels of volumetric energy density and different levels of inter layer time is reported. The study has been conducted on specimens with an application relevant build height (>100 mm). Furthermore, the evolution of the intrinsic preheating temperature during the build-up of specimens was monitored using a thermographic in-situ monitoring set-up. By applying recently determined emissivity values of 316L powder layers, real temperatures could be quantified. Heat accumulation led to preheating temperatures of up to about 600 °C. Significant differences in the preheating temperatures were discussed with respect to the individual process parameter combinations, including the build height. A strong effect of the inter layer time on the heat accumulation was observed. A shorter inter layer time resulted in an increase of the preheating temperature by more than a factor of 2 in the upper part of the specimens compared to longer inter layer times. This, in turn, resulted in heterogeneity of the microstructure and differences in material properties within individual specimens. The resulting differences in the microstructure were analyzed using electron back scatter diffraction and scanning electron microscopy. Results from chemical analysis as well as electron back scatter diffraction measurements indicated stable conditions in terms of chemical alloy composition and austenite phase content for the used set of parameter combinations. However, an increase of the average grain size by more than a factor of 2.5 could be revealed within individual specimens. Additionally, differences in feature size of the solidification cellular substructure were examined and a trend of increasing cell sizes was observed. This trend was attributed to differences in solidification rate and thermal gradients induced by differences in scanning velocity and preheating temperature. A change of the thermal history due to intrinsic preheating could be identified as the main cause of this heterogeneity. It was induced by critical combinations of the energy input and differences in heat transfer conditions by variations of the inter layer time. The microstructural variations were directly correlated to differences in hardness. KW - Additive manufacturing KW - Laser powder bed fusion KW - In-situ process monitoring KW - Thermography KW - Heat accumulation KW - Inter layer time KW - Cellular substructure PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-529240 DO - https://doi.org/10.3390/met11071063 VL - 11 IS - 7 SP - 1063 PB - MDPI CY - Basel, Schweiz AN - OPUS4-52924 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Moll, J. A1 - Wang, Cui A1 - Päpcke, A. A1 - Förster, C. A1 - Resch-Genger, Ute A1 - Lochbrunner, S. A1 - Heinze, K. T1 - Green Light Activation of Push-Pull Ruthenium(II) Complexes N2 - Synthesis, characterization, electrochemistry, and photophysics of novel homo- and heteroleptic ruthenium(II) complexes [Ru(cpmp)2] 2+ (22+) and [Ru(cpmp)(ddpd)]2+ (32+) bearing the tridentate ligands 6,2’’-carboxypyridyl-2,2’-methylamine-pyridylpyridine (cpmp) and N,N’-dimethyl-N,N’-dipyridin-2-ylpyridine-2,6-diamine (ddpd) are reported. The complexes possess one (32+) or two (22+) electron-deficient dipyridyl ketone fragments as electron accepting sites enabling intraligand charge transfer (ILCT), ligand-toligand charge transfer (LL’CT) and low-energy metal-to-ligand charge transfer (MLCT) absorptions. The latter peak around 544 nm (green light). 22+ shows 3MLCT phosphorescence in the red to near-infrared spectral region at room temperature in deaerated acetonitrile solution with an emission quantum yield of 1.3 % and a 3MLCT lifetime of 477 ns, while 3 2+ is much less luminescent. This different behaviour is ascribed to the energy gap law and the shape of the parasitic excited 3MC state potential energy surface. This study highlights the importance of the excited state energies and geometries for the actual excited state dynamics. Aromatic and aliphatic amines reductively quench the excited state of 22+ paving the way to photocatalytic applications using low-energy green light as exemplified with the green-light sensitized thiol-ene click reaction. KW - Green light excitation KW - Ruthenium(II) complexes KW - Phosphorescence KW - MLCT KW - Photoinduced electron transfer PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-506759 DO - https://doi.org/10.1002/chem.202000871 SP - 1 EP - 13 PB - Wiley-VCH Verlag AN - OPUS4-50675 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Morcillo, Dalia A1 - Winckelmann, Alexander A1 - Frick, Daniel A. A1 - Jacobsen, Lars A1 - Seger, Tino A1 - Florek, Stefan A1 - Richter, Silke A1 - Vogl, Jochen A1 - Recknagel, Sebastian A1 - Panne, Ulrich A1 - Abad Andrade, Carlos Enrique T1 - Lithium isotope ratio analysis of geological samples using atomic absorption spectrometry with improved spectral resolution N2 - This study introduces an improved spectrometric method with enhanced precision to determine isotope ratios in geological samples without chromatographic separation. Firstly, the improvement is achieved by increasing the spectral resolution of the spectrometer applied in well-known high-resolution continuum source atomic absorption spectrometry (HR-CS-AAS). The resulting resolving power and linear dispersion of the upgraded setup, which is denoted in the following as HR+CS-AAS, is well adapted to the line widths of the Li isotope components we investigated. Secondly, our proposed method combines optical absorption spectrometry with machine learning data analysis using an extreme gradient boosting algorithm (XGBoost). This method was applied to analyze certified geological reference materials with δLSVEC(7Li/6Li) (hereafter δ7Li) values ranging from −0.5 ‰ to 4.5 ‰. With a pixel related optical resolving power of λ/∆λ ≈ 780 000, we obtain precisions in δ7Li measurements from 1.0 ‰ to 2.5 ‰. The method is validated by comparing the results with multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS), confirming its metrological compatibility. This work presents a fast, robust, and reliable method for δ7Li measurement in geological samples. KW - Isotope KW - High-resolution continuum source atomic absorption spectroscopy KW - Lithium KW - Machine learning KW - Echelle spectrometer PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-611807 DO - https://doi.org/10.1016/j.sab.2024.107013 VL - 220 SP - 1 EP - 5 PB - Elsevier BV AN - OPUS4-61180 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Morcillo, Dalia A1 - Winckelmann, Alexander A1 - Oelze, Marcus A1 - Leonhardt, Robert A1 - Schmidt, Anita A1 - Richter, Silke A1 - Recknagel, Sebastian A1 - Vogl, Jochen A1 - Panne, Ulrich A1 - Abad Andrade, Carlos Enrique T1 - Exploring Age-Induced Lithium Isotope Fractionation in Lithium-Ion Batteries using Microwave-Induced Cold Nitrogen Plasma Mass Spectrometry N2 - This study explores Microwave-Inductively Coupled Atmospheric-pressure Plasma Mass Spectrometry (MICAP-MS) as a cost-effective alternative to Multi-Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICP-MS) for analyzing lithium isotopic composition in lithium-ion batteries (LIBs). We investigate the performance of MICAP-MS in measuring Li isotope ratios in new and aged commercial lithium cobalt oxide (LCO) batteries. Our results show that MICAP-MS, operating under cold plasma conditions at 800 W with an 8 mm torch position, achieves results metrologically compatible with MC-ICP-MS, with a precision ranging from 0.6‰ to 3.4‰ for δ7Li values. MICAP-MS benefits from a dielectric resonator for uniform plasma, better ion velocity control, and higher energy efficiency. Optimal settings were identified with dwell times of 10 ms for 6Li and 1 ms for 7Li. The study of LIBs revealed that 6Li migrates towards the anode over multiple charge–discharge cycles, causing 7Li to accumulate in the cathode, a fractionation effect that becomes more pronounced with prolonged cycling. MICAP-MS provides a cost-effective, precise alternative to MC-ICP-MS, with lower operational costs and enhanced portability, advancing the study of isotopic fractionation and aging in lithium-ion batteries. KW - MICAP-MS KW - Lithium KW - Battery aging KW - Lithium isotopes KW - Nitrogen plasma KW - Isotope fractionation KW - lithium cobalt oxide KW - LCO PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-643777 DO - https://doi.org/10.1039/d4ja00324a SN - 0267-9477 SP - 1 EP - 11 PB - Royal Society of Chemistry (RSC) AN - OPUS4-64377 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mrkwitschka, Paul A1 - Rühle, Bastian A1 - Kuchenbecker, Petra A1 - Löhmann, Oliver A1 - Lindemann, Franziska A1 - Hodoroaba, Vasile-Dan T1 - Embedding and cross-sectioning as a sample preparation procedure for accurate and representative size and shape measurement of nanopowders N2 - Reliable measurement of the size of polydisperse, complex-shaped commercial nanopowders is a difficult but necessary task, e.g., for regulatory requirements and toxicity risk assessment. Suitable methods exist for the accurate characterization of the size of non-aggregated, stabilized, spherical and monodisperse nanoparticles. In contrast, industrial nanoscale powders usually require dedicated sample preparation procedures developed for the analysis method of choice. These nano-powders tend to agglomerate and/or aggregate, a behavior which in combination with an innate broad particle size distribution and irregular shape often significantly alters the achievable accuracy of the measured size parameters. The present study systematically tests two commercially available nanoscale powders using different sample preparation methods for correlative analysis by scanning electron microscopy, dynamic light scattering, Brunauer–Emmet–Teller method and differential mobility analysis. One focus was set on the sample preparation by embedding nanoparticles in carbon-based hot-mounting resin. Literature on this topic is scarce and the accuracy of the data extracted from cross sections of these particles is unclearly stated. In this paper systematic simulations on the deviation of the size parameters of well-defined series of nanoparticles with different shapes from the nominal value were carried out and the contributing factors are discussed. KW - Nanopowder KW - Electron microscopy KW - Sample preparation KW - Cross-sectioning KW - Cerium oxide KW - Zinc oxide PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-593289 DO - https://doi.org/10.1038/s41598-023-51094-0 SN - 2045-2322 VL - 14 SP - 1 EP - 10 PB - Springer Nature CY - London AN - OPUS4-59328 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mugani, R. A1 - El Khalloufi, F. A1 - Kasada, M. A1 - Redouane, E. M. A1 - Haida, M. A1 - Aba, R. P. A1 - Essadki, Y. A1 - Zerrifi, S. E. A. A1 - Herter, Sven-Oliver A1 - Hejjaj, A. A1 - Aziz, F. A1 - Ouazzani, N. A1 - Azevedo, J. A1 - Campos, A. A1 - Putschew, A. A1 - Grossart, H.-P. A1 - Mandi, L. A1 - Vasconcelos, V. A1 - Oudra, B. T1 - Monitoring of toxic cyanobacterial blooms in Lalla Takerkoust reservoir by satellite imagery and microcystin transfer to surrounding farms N2 - Cyanobacterial harmful algal blooms (CyanoHABs) threaten public health and freshwater ecosystems worldwide. In this study, our main goal was to explore the dynamics of cyanobacterial blooms and how microcystins (MCs) move from the Lalla Takerkoust reservoir to the nearby farms. We used Landsat imagery, molecular analysis, collecting and analyzing physicochemical data, and assessing toxins using HPLC. Our investigation identified two cyanobacterial species responsible for the blooms: Microcystis sp. and Synechococcus sp. Our Microcystis strain produced three MC variants (MC-RR, MC-YR, and MC-LR), with MC-RR exhibiting the highest concentrations in dissolved and intracellular toxins. In contrast, our Synechococcus strain did not produce any detectable toxins. To validate our Normalized Difference Vegetation Index (NDVI) results, we utilized limnological data, including algal cell counts, and quantified MCs in freeze-dried Microcystis bloom samples collected from the reservoir. Our study revealed patterns and trends in cyanobacterial proliferation in the reservoir over 30 years and presented a historical map of the area of cyanobacterial infestation using the NDVI method. The study found that MC-LR accumulates near the water surface due to the buoyancy of Microcystis. The maximum concentration of MC-LR in the reservoir water was 160 μg/L. In contrast, 4 km downstream of the reservoir, the concentration decreased by a factor of 5.39 to 29.63 μg/L, indicating a decrease in MC-LR concentration with increasing distance from the bloom source. Similarly, the MC-YR concentration decreased by a factor of 2.98 for the same distance. Interestingly, the MC distribution varied with depth, with MC-LR dominating at the water surface and MC-YR at the reservoir outlet at a water depth of 10 m. Our findings highlight the impact of nutrient concentrations, environmental factors, and transfer processes on bloom dynamics and MC distribution. We emphasize the need for effective management strategies to minimize toxin transfer and ensure public health and safety. KW - Cyanotoxin KW - HPLC-MS/MS KW - Surface water PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-623672 DO - https://doi.org/10.1016/j.hal.2024.102631 SN - 1568-9883 VL - 135 SP - 1 EP - 14 PB - Elsevier CY - Amsterdam AN - OPUS4-62367 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Munir, R. A1 - Lisec, Jan A1 - Jaeger, Carsten A1 - Zaidi, N. T1 - Abundance, fatty acid composition and saturation index of neutral lipids in colorectal cancer cell lines N2 - Lipid droplets, the dynamic organelles that store Triglycerides (TG) and cholesterol esters (CE), are highly accumulated in colon cancer cells. This work studies the TG and CE subspecies profile in colon carcinoma cell lines, SW480 derived from primary tumor, and SW620 derived from a metastasis of the same tumor. It was previously reported that the total TG and CE content is dramatically higher in SW620 cells; however, TG and CE subspecies profile has not been investigated in detail. The work presented here confirms that the total TG and CE Content is significantly higher in the SW620 cells. Moreover, the fatty acid (FA) composition of TG is significantly altered in the SW620 cells, with significant decrease in the abundance of saturated triglycerides. This resulted in a significantly decreased TG saturation index in the SW620 cells. The saturation index of CE was also significantly decreased in the SW620 cells. KW - Mass Spectroscopy KW - Metabolomics KW - Cancer PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-533504 DO - https://doi.org/10.18388/abp.2020_5465 VL - 68 IS - 1 SP - 1 EP - 4 PB - ABP Acta Biochimica Polonica AN - OPUS4-53350 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Munir, R. A1 - Noureen, N. A1 - Bashir, M. A1 - Shoaib, N. A1 - Ashraf, A. A1 - Lisec, Jan A1 - Zaidi, N. T1 - Cancer Awareness Measure (CAM) and Cancer Awareness Measure MYthical Causes Scale (CAM‑MY) scores in Pakistani population N2 - Lifestyle modifications could prevent almost one‑third to one‑half of all cancer cases. The awareness of cancer risk factors could motivate people to make such changes in their behaviors and lifestyles. This work aims to investigate the cancer awareness level in the Pakistani population. Telephone interviews of 657 individuals in Pakistan were carried out using the Cancer Awareness Measure (CAM) and Cancer Awareness Measure–MYthical Causes Scale (CAM‑MY). We observed that participants scored significantly better on the CAM scale than the CAM‑MY scale, and CAM scores were negatively associated with CAM‑MY scores. Years of formal education or a biology major at undergraduate or graduate level did not affect our population’s cancer awareness levels. Age displayed a weak but statistically significant negative association with CAM scores. Most participants failed to identify modifiable cancer risk factors, e.g., low physical activity. Efforts should be made to improve awareness of modifiable risk factors. We observed that brief training sessions could markedly improve people’s understanding of cancer risk factors and myths. KW - Cancer KW - Cancer awareness measure KW - Cancer risk PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-548960 DO - https://doi.org/10.1038/s41598-022-13012-8 SN - 2045-2322 VL - 12 IS - 1 SP - 1 EP - 10 PB - Nature Publishing Group CY - London AN - OPUS4-54896 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Musyanovych, A. A1 - Grimmer, Christoph A1 - Sadak, A. E. A1 - Heßling, L. A1 - Lüdicke, M. A1 - Bilsel, M. A1 - Horn, Wolfgang A1 - Richter, Matthias T1 - Polymer Capsules with Volatile Organic Compounds as Reference Materials for Controlled Emission N2 - Encapsulation of volatile organic compounds (VOCs) that could evaporate at a defined rate is of immense interest for application in emission reference materials (ERMs). Polyurethane/polyurea microcapsules with various VOC active ingredients (limonene, pinene, and toluene) were successfully produced by interfacial polymerization with Shirasu porous glass membrane emulsification in a size range between 10 and 50 μm. The effect of surfactant, VOC, monomer(s) type, and ratio has a great effect on the formulation process and morphology of capsules. The type of VOC played a significant role in the encapsulation efficiency. Due to the difference in vapor pressure and VOC/water interfacial tension, the formulation for encapsulation was optimized for each individual VOC. Furthermore, to achieve effective stability of the large droplets/capsules, a combination of ionic and nonionic surfactants was used. Optical and scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA), were used to characterize the optimized microcapsules. The results showed that the obtained microcapsules exhibited a spherical shape and core–shell morphology and featured characteristic urethane-urea bonds. The amount of encapsulated VOC ranges between 54 and 7 wt %. The emission tests were performed with the help of the emission test chamber procedure (EN 16516). The limonene-loaded polyurethane/polyurea microcapsules show a change in emission rate of less than 10% within 14 days and can be considered as a potential candidate for use as an ERM. KW - Polymer microcapsules KW - Membrane emulsification KW - Polyaddition KW - Volatile organic compound (VOC) KW - Emission testing PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-619227 DO - https://doi.org/10.1021/acsami.4c12826 SN - 1944-8252 VL - 16 IS - 50 SP - 69999 EP - 70009 PB - ACS AN - OPUS4-61922 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Möckel, J. A1 - Brangsch, J. A1 - Reimann, C. A1 - Kaufmann, Jan Ole A1 - Sack, I. A1 - Mangarova, D. B. A1 - Kader, A. A1 - Taupitz, M. A1 - Adams, L. C. A1 - Keller, S. A1 - Ludwig, A. A1 - Hamm, B. A1 - Botnar, R. M. A1 - Makowski, M. R. T1 - Assessment of Albumin ECM Accumulation and Inflammation as Novel In Vivo Diagnostic Targets for Multi-Target MR Imaging N2 - Atherosclerosis is a progressive inflammatory vascular disease characterized by endothelial dysfunction and plaque burden. Extracellular matrix (ECM)-associated plasma proteins play an important role in disease development. Our magnetic resonance imaging (MRI) study investigates the feasibility of using two different molecular MRI probes for the simultaneous assessment of ECM-associated intraplaque albumin deposits caused by endothelial damage and progressive inflammation in atherosclerosis. Male apolipoprotein E-deficient (ApoE-/-)-mice were fed a high-fat diet (HFD) for 2 or 4 months. Another ApoE-/--group was treated with pravastatin and received a HFD for 4 months. T1- and T2*-weighted MRI was performed before and after albumin-specific MRI probe (gadofosveset) administration and a macrophage-specific contrast agent (ferumoxytol). Thereafter, laser ablation inductively coupled plasma mass spectrometry and histology were performed. With advancing atherosclerosis, albumin-based MRI signal enhancement and ferumoxytol-induced signal loss areas in T2*-weighted MRI increased. Significant correlations between contrast-to-noise-ratio (CNR) post-gadofosveset and albumin stain (R2 = 0.78, p < 0.05), and signal loss areas in T2*-weighted MRI with Perls’ Prussian blue stain (R2 = 0.83, p < 0.05) were observed. No interference of ferumoxytol with gadofosveset enhancement was detectable. Pravastatin led to decreased inflammation and intraplaque albumin. Multi-target MRI combining ferumoxytol and gadofosveset is a promising method to improve diagnosis and treatment monitoring in atherosclerosis. KW - Magnetic resonance imaging KW - MRI KW - Imaging KW - Human serum albumin KW - Extracellular matrix KW - Macrophages KW - Contrast agent KW - Atherosclerotic plaques KW - Gadofosveset KW - Aneurysm PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-536725 DO - https://doi.org/10.3390/biology10100964 VL - 10 IS - 10 SP - 1 EP - 16 PB - MDPI CY - Basel AN - OPUS4-53672 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Neamtu, M. A1 - Nadejde, C. A1 - Brinza, L. A1 - Dragos, O. A1 - Gherghel, D. A1 - Paul, Andrea T1 - Iron phthalocyanine-sensitized magnetic catalysts for BPA photodegradation N2 - The catalytic behavior of iron phthalocyanine (FePc)-sensitized magnetic nanocatalysts was evaluated for their application in the oxidative treatment of Bisphenol A (BPA) under mild environmental conditions. Two types of FePc (Fe(II)Pc and Fe(III)Pc), which are highly photosensitive compounds, were immobilized on the surface of functionalized magnetite. The nanomaterials were characterized by high resolution transmission electron microscopy (HR-TEM), X-ray difraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analyses (TGA). The generation of singlet Oxygen by nanomaterials was also investigated. In the presence of UVA light exposure (365nm) and 15mM H2O2, the M@Fe(III)Pc photocatalyst gave the best results; for a catalyst concentration of 2.0gL −1, around 60% BPA was removed after 120min of reaction. These experimental conditions were further tested under natural solar light exposure, for which also M@Fe(III)Pc exhibited enhanced oxidative catalytic activity, being able to remove 83% of BPA in solution. The water samples were less cytotoxic after treatment, this being confrmed by the MCF-7 cell viability assay. KW - Photosensitization KW - magnetic nanocatalysts KW - BPA removal PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-506368 DO - https://doi.org/10.1038/s41598-020-61980-6 VL - 10 IS - 1 SP - 5376 AN - OPUS4-50636 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nelson, G. A1 - Boehm, U. A1 - Bagley, S. A1 - Bajcsy, P. A1 - Bischof, J. A1 - Brown, C. M. A1 - Dauphin, A. A1 - Dobbie, I. M. A1 - Eriksson, J. E. A1 - Faklaris, O. A1 - Fernandez-Rodriguez, J. A1 - Ferrand, A. A1 - Gelman, L, A1 - Gheisari, A. A1 - Hartmann, H. A1 - Kukat, C. A1 - Laude, A. A1 - Mitkovski, M. A1 - Munck, S. A1 - North, A. J. A1 - Rasse, T. A1 - Resch-Genger, Ute A1 - Schuetz, L. C. A1 - Seitz, A. A1 - Strambio-De-Castillia, C. A1 - Swedlow, J. R. A1 - Alexopoulos, I. A1 - Aumayr, K. A1 - Avilov, S. A1 - Bakker, G.-J. A1 - Bammann, R. R. A1 - Bassi, A. A1 - Beckert, H. A1 - Beer, S. A1 - Belyaev, Y. A1 - Bierwagen, J. A1 - Birngruber, K. A. A1 - Bosch, M. A1 - Breitlow, J. A1 - Cameron, L. A. A1 - Chalfoun, J. A1 - Chambers, J. J. A1 - Chen, C.-L. A1 - Conde-Sousa, E. A1 - Corbett, A. D. A1 - Cordelieres, F. P. A1 - Del Nery, E. A1 - Dietzel, R. A1 - Eismann, F. A1 - Fazeli, E. A1 - Felscher, A. A1 - Fried, H. A1 - Gaudreault, N. A1 - Goh, W. I. A1 - Guilbert, T. A1 - Hadleigh, R. A1 - Hemmerich, P. A1 - Holst, G. A. A1 - Itano, M. S. A1 - Jaffe, C. B. A1 - Jambor, H. K. A1 - Jarvis, S. C. A1 - Keppler, A. A1 - Kirchenbuechler, D. A1 - Kirchner, M. A1 - Kobayashi, N. A1 - Krens, G. A1 - Kunis, S. A1 - Lacoste, J. A1 - Marcello, M. A1 - Martins, G. G. A1 - Metcalf, D. J. A1 - Mitchell, C. A. A1 - Moore, J. A1 - Mueller, T. A1 - Nelson, M. S. A1 - Ogg, S. A1 - Onami, S. A1 - Palmer, A. L. A1 - Paul-Gilloteaux, P. A1 - Pimentel, J. A. A1 - Plantard, L. A1 - Podder, S. A1 - Rexhepaj, E. A1 - Royon, A. A1 - Saari, M. A. A1 - Schapman, D. A1 - Schoonderwoert, V. A1 - Schroth-Diez, B. A1 - Schwartz, S. A1 - Shaw, M. A1 - Spitaler, M. A1 - Stoeckl, M. T. A1 - Sudar, D. A1 - Teillon, J. A1 - Terjung, S. A1 - Thuenauer, R. A1 - Wilms, C. D. A1 - Wright, G. D. A1 - Nitschke, R. T1 - QUAREP-LiMi: A community-driven initiative to establish guidelines for quality assessment and reproducibility for instruments and images in light microscopy N2 - A modern day light microscope has evolved from a tool devoted to making primarily empirical observations to what is now a sophisticated, quantitative device that is an integral part of both physical and life science research. Nowadays, microscopes are found in nearly every experimental laboratory. However, despite their prevalent use in capturing and quantifying scientific phenomena, neither a thorough understanding of the principles underlying quantitative imaging techniques nor appropriate knowledge of how to calibrate, operate and maintain microscopes can be taken for granted. This is clearly demonstrated by the well-documented and widespread difficulties that are routinely encountered in evaluating acquired data and reproducing scientific experiments. Indeed, studies have shown that more than 70% of researchers have tried and failed to repeat another scientist’s experiments, while more than half have even failed to reproduce their own experiments1. One factor behind the reproducibility crisis of experiments published in scientific journals is the frequent underreporting of imaging methods caused by a lack of awareness and/or a lack of knowledge of the applied technique2,3. Whereas quality control procedures for some methods used in biomedical research, such as genomics (e.g., DNA sequencing, RNA-seq) or cytometry, have been introduced (e.g. ENCODE4), this issue has not been tackled for optical microscopy instrumentation and images. Although many calibration standards and protocols have been published, there is a lack of awareness and agreement on common Standards and guidelines for quality assessment and reproducibility5. In April 2020, the QUality Assessment and REProducibility for instruments and images in Light Microscopy (QUAREP-LiMi) initiative6 was formed. This initiative comprises imaging scientists from academia and industry who share a common interest in achieving a better understanding of the performance and limitations of microscopes and improved quality control (QC) in light microscopy. The ultimate goal of the QUAREP-LiMi initiative is to establish a set of common QC standards, guidelines, metadata models7,8, and tools9,10, including detailed protocols, with the ultimate aim of improving reproducible advances in scientific research. This White Paper 1) summarizes the major obstacles identified in the field that motivated the launch of the QUAREP-LiMi initiative; 2) identifies the urgent need to address these obstacles in a grassroots manner, through a community of Stakeholders including, researchers, imaging scientists11, bioimage analysts, bioimage informatics developers, corporate partners, Funding agencies, standards organizations, scientific publishers, and observers of such; 3) outlines the current actions of the QUAREPLiMi initiative, and 4) proposes future steps that can be taken to improve the dissemination and acceptance of the proposed guidelines to manage QC. To summarize, the principal goal of the QUAREP-LiMi initiative is to improve the overall quality and reproducibility of light microscope image data by introducing broadly accepted standard practices and accurately captured image data metrics. KW - Fluorescence KW - Microscopy KW - Quality assurance KW - Comparability KW - Imaging KW - Standards KW - Reference materials KW - Reliability KW - Data KW - Reference data KW - Biology KW - Medicine KW - Life science PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-530629 DO - https://doi.org/10.1111/jmi.13041 SN - 1365-2818 VL - 284 IS - 1 SP - 56 EP - 73 PB - Wiley-Blackwell CY - Oxford AN - OPUS4-53062 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nerger, Tino A1 - Neumann, Patrick P. A1 - Weller, Michael G. T1 - Drone-Based Localization of Hazardous Chemicals by Passive Smart Dust N2 - The distribution of tiny sensors over a specific area was first proposed in the late 1990s as a concept known as smart dust. Several efforts focused primarily on computing and networking capabilities, but quickly ran into problems related to power supply, cost, data transmission, and environmental pollution. To overcome these limitations, we propose using paper-based (confetti-like) chemosensors that exploit the inherent selectivity of chemical reagents, such as colorimetric indicators. In this work, cheap and biodegradable passive sensors made from cellulose could successfully indicate the presence of hazardous chemicals, e.g., strong acids, by a significant color change. A conventional color digital camera attached to a drone could easily detect this from a safe distance. The collected data were processed to define the hazardous area. Our work presents a combination of the smart dust concept, chemosensing, paper-based sensor technology, and low-cost drones for flexible, sensitive, economical, and rapid detection of hazardous chemicals in high-risk scenarios. KW - Cellulose KW - Passive Smart Dust KW - Drohne KW - Kolorimetrische Sensoren PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-614641 DO - https://doi.org/10.3390/s24196195 VL - 24 IS - 19 SP - 1 EP - 16 PB - MDPI AN - OPUS4-61464 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nordholt, Niclas A1 - O'Hara, Kate A1 - Resch-Genger, Ute A1 - Blaskovich, M. A1 - Rühle, Bastian A1 - Schreiber, Frank T1 - A fluorescently labelled quaternary ammonium compound (NBD-DDA) to study resistance mechanisms in bacteria N2 - Quaternary ammonium compounds (QACs) are widely used as active agents in disinfectants, antiseptics, and preservatives. Despite being in use since the 1940s, there remain multiple open questions regarding their detailed mode-of-action and the mechanisms, including phenotypic heterogeneity, that can make bacteria less susceptible to QACs. To facilitate studies on resistance mechanisms towards QACs, we synthesized a fluorescent quaternary ammonium compound, namely N-dodecyl-N,N-dimethyl-[2-[(4-nitro-2,1,3-benzoxadiazol-7-yl)amino]ethyl]azanium-iodide (NBD-DDA). NBD-DDA is readily detected by flow cytometry and fluorescence microscopy with standard GFP/FITC-settings, making it suitable for molecular and single-cell studies. As a proof-of-concept, NBD-DDA was then used to investigate resistance mechanisms which can be heterogeneous among individual bacterial cells. Our results reveal that the antimicrobial activity of NBD-DDA against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa is comparable to that of benzalkonium chloride (BAC), a widely used QAC, and benzyl-dimethyl-dodecylammonium chloride (BAC12), a mono-constituent BAC with alkyl-chain length of 12 and high structural similarity to NBD-DDA. Characteristic time-kill kinetics and increased tolerance of a BAC tolerant E. coli strain against NBD-DDA suggest that the mode of action of NBD-DDA is similar to that of BAC. As revealed by confocal laser scanning microscopy (CLSM), NBD-DDA is preferentially localized to the cell envelope of E. coli, which is a primary target of BAC and other QACs. Leveraging these findings and NBD-DDA‘s fluorescent properties, we show that reduced cellular accumulation is responsible for the evolved BAC tolerance in the BAC tolerant E. coli strain and that NBD-DDA is subject to efflux mediated by TolC. Overall, NBD-DDA’s antimicrobial activity, its fluorescent properties, and its ease of detection render it a powerful tool to study resistance mechanisms of QACs in bacteria and highlight its potential to gain detailed insights into its mode-of-action. KW - Antimicrobial resistance KW - Bacteria KW - Disinfection KW - Biocides PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-563811 DO - https://doi.org/10.3389/fmicb.2022.1023326 SN - 1664-302X IS - 13 SP - 1 EP - 13 PB - Frontiers Media CY - Lausanne AN - OPUS4-56381 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Noureen, N. A1 - Shah, F. A. A1 - Lisec, Jan A1 - Usman, H. A1 - Khalid, M. A1 - Munir, R. A1 - Zaidi, N. T1 - Revisiting the association between human leukocyte antigen and end-stage renal disease N2 - Multiple works have studied possible associations between human leukocyte antigen (HLA) alleles and end stage renal disease (ESRD) showing, however, contradictory and inconsistent results. Here, we revisit the association between ESRD and HLA antigens, comparing HLA polymorphism (at HLA-A, -B, -C, -DRB1, -DQB1 and DQA1 loci) in ESRD patients (n = 497) and controls (n = 672). Our data identified several HLA alleles that displayed a significant positive or negative association with ESRD. We also determined whether heterozygosity or homozygosity of the ESRD-associated HLA alleles at different loci could modify the prevalence of the disease. Few HLA allele combinations displayed significant associations with ESRD, among which A*3_26 combination showed the highest strength of association (OR = 4.488, P≤ 0.05) with ESRD. Interestingly, the age of ESRD onset was not affected by HLA allele combinations at different loci. We also performed an extensive literature analysis to determine whether the association of HLA to ESRD can be similar across different ethnic groups. Our analysis showed that at least certain HLA alleles, HLA-A*11, HLA-DRB1*11, and HLA-DRB1*4, display a significant association with ESRD in different ethnic groups. The findings of our study will help in determining possible protective or susceptible roles of various HLA alleles in ESRD. KW - Cancer KW - Human leukocyte antigen (HLA) KW - Renal disease PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-512651 DO - https://doi.org/10.1371/journal.pone.0238878 SN - 1932-6203 VL - 15 IS - 9 SP - e0238878 AN - OPUS4-51265 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nowatzky, Yannek A1 - Russo, Francesco Friedrich A1 - Lisec, Jan A1 - Kister, Alexander A1 - Reinert, Knut A1 - Muth, Thilo A1 - Benner, Philipp T1 - FIORA: Local neighborhood-based prediction of compound mass spectra from single fragmentation events N2 - Non-targeted metabolomics holds great promise for advancing precision medicine and biomarker discovery. However, identifying compounds from tandem mass spectra remains a challenging task due to the incomplete nature of spectral reference libraries. Augmenting these libraries with simulated mass spectra can provide the necessary references to resolve unmatched spectra, but generating high-quality data is difficult. In this study, we present FIORA, an open-source graph neural network designed to simulate tandem mass spectra. Our main contribution lies in utilizing the molecular neighborhood of bonds to learn breaking patterns and derive fragment ion probabilities. FIORA not only surpasses state-of-the-art fragmentation algorithms, ICEBERG and CFM-ID, in prediction quality, but also facilitates the prediction of additional features, such as retention time and collision cross section. Utilizing GPU acceleration, FIORA enables rapid validation of putative compound annotations and large-scale expansion of spectral reference libraries with high-quality predictions. KW - Metabolomics KW - Machine Learning KW - Mass spectrometry KW - Bioinformatics PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-627585 DO - https://doi.org/10.1038/s41467-025-57422-4 SN - 2041-1723 VL - 16 IS - 1 SP - 1 EP - 17 PB - Springer Science and Business Media LLC AN - OPUS4-62758 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nxumalo, T. A1 - Akhdhar, A. A1 - Mueller, V. A1 - Simon, Fabian A1 - von der Au, Marcus A1 - Cossmer, Antje A1 - Pfeifer, Jens A1 - Krupp, E. A1 - Meermann, Björn A1 - Kindness, A. A1 - Feldmann, J. T1 - EOF and target PFAS analysis in surface waters affected by sewage treatment effluents in Berlin, Germany N2 - Per- and polyfuoroalkyl substances (PFAS) are emerging organic pollutants and can occur in surface and groundwater. To identify the degree of pollution in surface water with PFAS, often targeted HPLC–ESI–MS/MS has been employed in which commonly 30–40 compounds are analyzed. However, other PFAS and organofuorines remain undetected. We sampled surface water of the river Spree and the Teltow Canal in Berlin, Germany, which are afected by the efuent discharge of wastewater treatment plants. Here, we employed high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS-GFMAS) for measuring extractable organofuorines (EOF) and compared in a mass balance approach the total fuorine to the identifed and quantifed PFAS from the targeted analysis. The analysis highlights that the EOF are in the range expected for an urban river system (Winchell et al. in Sci Total Environ 774, 2021). However, downstream of an efuent discharge, the EOF increased by one order of magnitude, e.g., 40.3 to 574 ng F L−1, along the Teltow Canal. From our target analytes, mostly short-chained perfuorinated carboxylic acids and sulfonates occur in the water, which however makes up less than 10% of the EOF. The increase in EOF in the Teltow Canal correlates well with the increase of perfuorohexanoic acid (PFHxA), indicating that PFHxA is characteristic for the discharged EOF but not responsible for the increase. Hence, it points to PFHxA precursor discharge. The study highlights that EOF screening using HR-CS-GFMAS is necessary to identify the full scale of pollution with regard to PFAS and other organofuorines such as pharmaceutical compounds from the efuent of WWTPs. KW - PFAS KW - WWTP KW - GF-MAS PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-580341 DO - https://doi.org/10.1007/s00216-022-04500-x VL - 415 SP - 1195 EP - 1204 PB - Springer AN - OPUS4-58034 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Onyenso, Gabriel A1 - AI-Zawity, Jiwar A1 - Farahbakhsh, Nastaran A1 - Schardt, Annika A1 - Yadigarli, Aydan A1 - Vakamulla Raghu, Swathi Naidu A1 - Engelhard, Carsten A1 - Müller, Mareike A1 - Schönherr, Holger A1 - Killian, Manuela S. T1 - Novel Ag-modified zirconia nanomaterials with antibacterial activity N2 - The outcome of an implant procedure largely depends on the implant's surface properties. Biomaterials are now designed to have surfaces with multifunctionality, such as favorable tissue integration and the ability to combat bacterial adhesion and colonization. Herein, we report on a simple approach to improve the antibacterial properties of zirconia nanotubes (ZrNTs) coatings by decorating with silver nanoparticles (AgNP), achieved through electrochemical anodization of a zirconium–silver alloy (Zr–Ag). The AgNPs were shown to partially consist of Ag2O, potentially enhancing the availability of Ag+ ions for antibacterial activity. The modified ZrNTs were characterized using SEM, EDS, ToF-SIMS, and XPS to determine their structural morphology and chemical composition, and were further subjected to antibacterial testing. The silver and zirconium ion release behavior was monitored via ICP-MS. ZrNTs decorated with AgNP exhibit strong antimicrobial activity (>99% bacterial killing) against both S. aureus and E. coli. Antimicrobial tests indicate that the antibacterial activity against the Gram-positive pathogen S. aureus was improved by a factor of 100 compared to unmodified ZrNTs, while unmodified ZrNTs already showed a comparable reduction of viable Gram-negative E. coli. This strategy illustrates a straightforward and effective modification that optimizes the interface between the host environment and the biomaterial surface to meet the very important criteria of biocompatibility and active antibacterial response. KW - Mass Spectrometry KW - Nanoparticles KW - Advanced Materials KW - ICP-MS KW - Antimicrobial material KW - ToF-SIMS PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653990 DO - https://doi.org/10.1039/d5ra07099f SN - 2046-2069 VL - 16 IS - 3 SP - 2286 EP - 2297 PB - Royal Society of Chemistry (RSC) AN - OPUS4-65399 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Orf, I. A1 - Tenenboim, H. A1 - Omranian, N. A1 - Nikoloski, Z. A1 - Fernie, A. R. A1 - Lisec, Jan A1 - Brotman, Y. A1 - Bromke, M. A. T1 - Transcriptomic and Metabolomic Analysis of a Pseudomonas-Resistant versus a Susceptible Arabidopsis Accession N2 - Accessions of one plant species may show significantly different levels of susceptibility to stresses. The Arabidopsis thaliana accessions Col-0 and C24 differ significantly in their resistance to the pathogen Pseudomonas syringae pv. tomato (Pst). To help unravel the underlying mechanisms contributing to this naturally occurring variance in resistance to Pst, we analyzed changes in transcripts and compounds from primary and secondary metabolism of Col-0 and C24 at different time points after infection with Pst. Our results show that the differences in the resistance of Col-0 and C24 mainly involve mechanisms of salicylic-acid-dependent systemic acquired resistance, while responses of jasmonic-acid-dependent mechanisms are shared between the two accessions. In addition, arginine metabolism and differential activity of the biosynthesis pathways of aliphatic glucosinolates and indole glucosinolates may also contribute to the resistance. Thus, this study highlights the difference in the defense response strategies utilized by different genotypes. KW - Mass Spectrometry KW - Arabidopsis KW - Resistance PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559549 DO - https://doi.org/10.3390/ijms232012087 VL - 23 IS - 20 SP - 1 EP - 27 PB - MDPI AN - OPUS4-55954 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Osiopova, Viktoriia A1 - Tavernaro, Isabella A1 - Ge, L. A1 - Kitzmann, W. R. A1 - Heinze, K. A1 - Reithofer, M. R. A1 - Resch-Genger, Ute T1 - Complete protection of NIR-luminescent molecular rubies from oxygen quenching in air by L-arginine-mediated silica nanoparticles N2 - The application of emerging luminophores such as near-infrared (NIR) emissive complexes based on earth-abundant chromium as central ion and triplet-triplet annihilation upconversion (TTA-UC) systems in air as optical reporters for bioimaging or photonic materials for energy conversion requires simple and efficient strategies for their complete protection from uminescence quenching by oxygen. Therefore, we explored the influence of sol–gel synthesis routes on the oxygen protection efficiency of the resulting core and core/shell silica nanoparticles (SiO2 NPs), utilizing the molecular ruby-type luminophores CrPF6 ([Cr(ddpd)2](PF6)3; ddpd = N,N'-dimethyl-N,N'-dipyridin-2-ylpyridin-2,6-diamine) and CrBF4 ([Cr(ddpd)2](BF4)3) with their oxygendependent, but polarity-, proticity-, viscosity-, and concentration-independent luminescence as optical probes for oxygen permeability. The sol–gel chemistry routes we assessed include the classical Stöber method and the underexplored Larginine approach, which relies on the controlled hydrolysis of tetraethoxysilane (TEOS) in a biphasic cyclohexane/water system with the catalyst L-arginine. As demonstrated by luminescence measurements of air- and argon-saturated dispersions of CrPF6- and CrBF4-stained SiO2 NPs of different size and particle architecture, utilizing the luminescence decay kinetics of argon-saturated solutions of CrPF6 and CrBF4 in acetonitrile (ACN) as benchmarks, only SiO2 NPs or shells synthesized by the L-arginine approach provided complete oxygen protection of the CrIII complexes under ambient conditions. We ascribe the different oxygen shielding efficiencies of the silica networks explored to differences in density and surface chemistry of the resulting nanomaterials and coatings, leading to different oxygen permeabilities. Our Larginine based silica encapsulation strategy can open the door for the efficient usage of oxygen-sensitive luminophores and TTA-UC systems as optical reporters and spectral shifters in air in the future. KW - Quality assurance KW - Fluorescence KW - Quantification KW - Advanced materials KW - Nano KW - Quantum yield KW - NIR KW - Characterization KW - Electron microscopy KW - Silica KW - Synthesis KW - Oxygen sensing KW - Surface KW - Doping KW - Lifetime KW - Cr(III) complex KW - Shielding KW - Sensing PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-638271 DO - https://doi.org/10.26599/NR.2025.94907241 SN - 1998-0000 VL - 18 IS - 3 SP - 1 EP - 13 PB - SciOpen AN - OPUS4-63827 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Oskoei, Párástu A1 - Afonso, Rúben A1 - Bastos, Verónica A1 - Nogueira, João A1 - Keller, Lisa-Marie A1 - Andresen, Elina A1 - Saleh, Maysoon I. A1 - Rühle, Bastian A1 - Resch-Genger, Ute A1 - Daniel-da-Silva, Ana L. A1 - Oliveira, Helena T1 - Upconversion Nanoparticles with Mesoporous Silica Coatings for Doxorubicin Targeted Delivery to Melanoma Cells N2 - Melanoma is one of the most aggressive skin cancers and requires innovative therapeutic strategies to overcome the limitations of conventional therapies. In this work, upconversion nanoparticles coated with mesoporous silica and functionalized with folic acid (UCNP@mSiO2-FA) were developed as a targeted nanocarrier system for the delivery of doxorubicin (DOX). The UCNPs were synthesized via thermal decomposition, coated with mesoporous silica shells, and functionalized with folic acid (FA) to enable receptor-mediated targeting. DOX was then loaded into the mesoporous silica coating by adsorption, yielding UCNP@mSiO2-FA-DOX. The different UCNPs were characterized for size, composition, colloidal stability, and loading and release of DOX. This comprehensive physicochemical characterization confirmed a high DOX loading efficiency and a slightly increased drug release under acidic conditions, mimicking the tumour microenvironment. In vitro assays using four melanoma cell lines (A375, B16-F10, MNT-1, and SK-MEL-28) revealed an excellent biocompatibility of UCNP@mSiO2-FA and a significantly higher cytotoxicity of UCNP@mSiO2-FA-DOX compared to unloaded UCNPs, in a dose-dependent manner. Cell cycle analysis demonstrated G2/M phase arrest after treatment with UCNP@mSiO2-FA-DOX, confirming its antiproliferative effect. Overall, UCNP@mSiO2-FA-DOX represents a promising nanoplatform for targeted melanoma therapy, combining active tumour targeting and enhanced anticancer efficacy. KW - Fluorescence KW - Synthesis KW - Nano KW - Particle KW - Silica KW - Cell KW - Uptake KW - Drug KW - Characterization KW - DOX KW - Imaging KW - Toxicity KW - Release KW - pH PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653596 DO - https://doi.org/10.3390/molecules31010074 SN - 1420-3049 VL - 31 IS - 1 SP - 1 EP - 18 PB - MDPI AG AN - OPUS4-65359 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Paul, Andrea ED - Reese, M. ED - Goldhammer, T. ED - Schmalsch, C. ED - Weber, J. ED - Bannick, C. G. T1 - Spectroscopic evidence for adsorption of natural organic matter on microplastics N2 - The interaction of microcroplastics (MP) with dissolved organic matter, especially humic substances, is of great importance in understanding the behavior of microplastics in aquatic ecosystems. Surface modification by humic substances plays an essential role in transport and interaction of MP with abiotic and biotic components. Previous studies on the interaction between MP and humic substances were largely based on a model compound, humic acid (Sigma-Aldrich). In our work, we therefore investigated the interaction of natural organic matter (NOM) sampled from a German surface water with low-density polyethylene particles (LDPE). Highpressure size exclusion chromatography (HPSEC) and UV/vis absorption and fluorescence spectroscopy were used to characterize the incubation solutions after modifications due to the presence of LDPE, and Raman spectroscopy was used to characterize the incubated microplastics. While the studies of the solutions generally showed only very small effects, Raman spectroscopic studies allowed clear evidence of the binding of humic fractions to MP. The comparison of the incubation of NOM and a lignite fulvic acid which also was tested further showed that specific signatures of the humic substances used could be detected by Raman spectroscopy. This provides an elegant opportunity to conduct broader studies on this issue in the future. KW - Humic matter KW - Raman KW - HPSEC KW - Fluorescence KW - MCR PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-574519 DO - https://doi.org/10.1002/appl.202200126 SN - 2702-4288 VL - 3 IS - 2 SP - 1 EP - 30 PB - Wiley-VCH CY - Weinheim AN - OPUS4-57451 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Paul, Andrea A1 - Liestmann, Zoe A1 - Zaenker, Steffen A1 - Vogel, Kristin A1 - Broszies, Tanja A1 - Ostermann, Markus T1 - How reliable is the X‐ray fluorescence‐based differentiation between glass wool and rock wool and the age classification of rock wool? N2 - AbstractA prerequisite for the recycling of mineral wool is information about the type of material, that is, whether it is glass wool or rock wool. As mineral wool produced before the year 2000 can be potentially carcinogenic, it is furthermore important to distinguish between “old” and “new” wool when handling the material. Based on VDI 3492, it is possible to determine the material and, in the case of rock wool, the age by analyzing the mass fractions of eight oxides, which are the main components of mineral wool. This study presents the X‐ray fluorescence (XRF) analyses of 141 man‐made mineral fibers collected in Germany. Only in a few cases it was not possible to clearly assign the material type. In contrast, the identification of “old” and “new” rock wool posed a challenge as there were many borderline samples. Based on the available data, a chemometric model was developed that can classify “old” and “new” RW with a sensitivity of 93% and 89% and with a specificity of 100% in both cases. However, care must be taken when oxide contents are close to the specification limits. The reason for this mainly lies in the overlapping intervals of key oxides as suggested by VDI 3492, and, to a lesser extent, in the uncertainties typically occurring in the XRF‐based analysis of oxides. With this study, a comprehensive collection and evaluation of XRF data on mineral wool is made available, which can serve as a reference database for future users. KW - Mineral wool KW - RFA KW - Multivariate data analysis KW - VDI 3492 PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-610285 DO - https://doi.org/10.1002/xrs.3451 SN - 1097-4539 SP - 1 EP - 11 PB - Wiley CY - New York, NY AN - OPUS4-61028 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Paul, Martin A1 - Tannenberg, Robert A1 - Tscheuschner, Georg A1 - Ponader, Marco A1 - Weller, Michael G. T1 - Cocaine detection by a laser-induced immunofluorometric biosensor N2 - The trafficking of illegal drugs by criminal networks at borders, harbors, or airports is an increasing issue for public health as these routes ensure the main supply of illegal drugs. The prevention of drug smuggling, including the installation of scanners and other analytical devices to detect small traces of drugs within a reasonable time frame, remains a challenge. The presented immunosensor is based on a monolithic affinity column with a large excess of immobilized hapten, which traps fluorescently labeled antibodies as long as the analyte cocaine is absent. In the presence of the drug, some binding sites of the antibody will be blocked, which leads to an immediate breakthrough of the labeled protein, detectable by highly sensitive laser-induced fluorescence with the help of a Peltier-cooled complementary metal-oxide-semiconductor (CMOS) camera. Liquid handling is performed with high-precision syringe pumps and microfluidic chip-based mixing devices and flow cells. The biosensor achieved limits of detection of 7 ppt (23 pM) of cocaine with a response time of 90 s and a total assay time below 3 min. With surface wipe sampling, the biosensor was able to detect 300 pg of cocaine. This immunosensor belongs to the most sensitive and fastest detectors for cocaine and offers near-continuous analyte measurement. KW - Online detection KW - Security KW - Monoclonal antibody KW - Microfluidic mixing KW - Microfluidics KW - Lab-on-a-chip KW - Monolithic column KW - Affinity chromatography KW - Laser-induced fluorescence KW - LIF KW - ELISA KW - Wipe test KW - Low-cost PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-534487 DO - https://doi.org/10.3390/bios11090313 VL - 11 IS - 9 SP - 1 EP - 15 PB - MDPI CY - Basel AN - OPUS4-53448 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Paul, Martin A1 - Tscheuschner, Georg A1 - Herrmann, Stefan A1 - Weller, Michael G. T1 - Fast Detection of 2,4,6-Trinitrotoluene (TNT) at ppt Level by a Laser-Induced Immunofluorometric Biosensor N2 - The illegal use of explosives by terrorists and other criminals is an increasing issue in public spaces, such as airports, railway stations, highways, sports venues, theaters, and other large buildings. Security in these environments can be achieved by different means, including the installation of scanners and other analytical devices to detect ultra-small traces of explosives in a very short time-frame to be able to take action as early as possible to prevent the detonation of such devices. Unfortunately, an ideal explosive detection system still does not exist, which means that a compromise is needed in practice. Most detection devices lack the extreme analytical sensitivity, which is nevertheless necessary due to the low vapor pressure of nearly all explosives. In addition, the rate of false positives needs to be virtually zero, which is also very difficult to achieve. Here we present an immunosensor system based on kinetic competition, which is known to be very fast and may even overcome affinity limitation, which impairs the performance of many traditional competitive assays. This immunosensor consists of a monolithic glass column with a vast excess of immobilized hapten, which traps the fluorescently labeled antibody as long as no explosive is present. In the case of the explosive 2,4,6-trinitrotoluene (TNT), some binding sites of the antibody will be blocked, which leads to an immediate breakthrough of the labeled protein, detectable by highly sensitive laser-induced fluorescence with the help of a Peltier-cooled complementary metal-oxide-semiconductor (CMOS) camera. Liquid handling is performed with high-precision syringe pumps and chip-based mixing-devices and flow-cells. The system achieved limits of detection of 1 pM (1 ppt) of the fluorescent label and around 100 pM (20 ppt) of TNT. The total assay time is less than 8 min. A cross-reactivity test with 5000 pM solutions showed no signal by pentaerythritol tetranitrate (PETN), 1,3,5-trinitroperhydro-1,3,5-triazine (RDX), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX). This immunosensor belongs to the most sensitive and fastest detectors for TNT with no significant cross-reactivity by non-related compounds. The consumption of the labeled antibody is surprisingly low: 1 mg of the reagent would be sufficient for more than one year of continuous biosensor operation. KW - Airport KW - Aviation KW - Bombs KW - Terrorism KW - Biosensing KW - Continuous Sensor KW - High-Speed KW - Ultrasensitive PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-511245 DO - https://doi.org/10.3390/bios10080089 VL - 10 IS - 8 SP - 89 PB - MDPI CY - Basel AN - OPUS4-51124 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Paul, Martin A1 - Weller, Michael G. T1 - Antibody screening by microarray technology - Direct identification of selective high-affinity clones N2 - The primary screening of hybridoma cells is a time-critical and laborious step during the development of monoclonal antibodies. Often, critical errors occur in this phase, which supports the notion that the generation of monoclonal antibodies with hybridoma technology is difficult to control and hence, a risky venture. We think that it is crucial to improve the screening process to eliminate most of the critical deficits of the conventional approach. With this new microarray-based procedure, several advances could be achieved: Selectivity for excellent binders, high-throughput, reproducible signals, avoidance of misleading avidity (multivalency) effects, and performance of simultaneous competition experiments. The latter can also be used to select clones of desired cross-reactivity properties. In this paper, a model system with two excellent clones against carbamazepine, two weak clones, and blank supernatant containing fetal bovine serum was designed to examine the effectiveness of the new system. The excellent clones could be detected largely independent of the immunoglobulin G (IgG) concentration, which is usually unknown during the clone screening since the determination and subsequent adjustment of the antibody concentration are not feasible in most cases. Furthermore, in this approach, the enrichment, isolation, and purification of IgG for characterization is not necessary. Raw cell culture supernatant can be used directly, even when fetal calf serum (FCS) or other complex media is used. In addition, an improved method for the oriented antibody-immobilization on epoxy-silanized slides is presented. Based on the results of this model system with simulated hybridoma supernatants, we conclude that this approach should be preferable to most other protocols leading to many false positives, causing expensive and lengthy elimination steps to weed out the poor clones. KW - ELISA KW - Immunoassay KW - Microarray KW - Lab-on-a-chip KW - Miniaturization KW - Aautomatisation KW - HTS KW - High-throughput KW - Screening KW - Fluorescence KW - Label KW - Hybridoma KW - Inhibition PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-503361 DO - https://doi.org/10.3390/antib9010001 SN - 2073-4468 VL - 9 IS - 1 SP - 1 EP - 16 PB - MDPI CY - Basel AN - OPUS4-50336 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pauli, Jutta A1 - Ramírez, A. A1 - Crasselt, C. A1 - Schmidt, W. A1 - Resch-Genger, Ute T1 - Utilizing optical spectroscopy and 2',7'-difluorofluorescein to characterize the early stages of cement hydration N2 - The increasingly sophisticated nature of modern, more environmentally friendly cementitious binders requires a better understanding and control particularly of the complex, dynamic processes involved in the early phase of cement hydration. In-situ monitoring of properties of a constantly changing system over a defined period of time calls for simple, sensitive, fast, and preferably also non-invasive methods like optical spectroscopy KW - Flourescence KW - Optical probe KW - Sensor KW - Dye KW - Flourescin KW - Photophysics KW - PH KW - Quantum yield KW - Quality assurance KW - Mechanism KW - Cement KW - Concrete KW - Building material KW - Hydration KW - Process monitoring PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-537176 DO - https://doi.org/10.1088/2050-6120/ac2da0 SN - 2050-6120 VL - 10 IS - 1 SP - 2 EP - 13 PB - IOP Science AN - OPUS4-53717 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Peter, Elisa K. A1 - Jaeger, Carsten A1 - Lisec, Jan A1 - Peters, R. Sven A1 - Mourot, Rey A1 - Rossel, Pamela E. A1 - Tranter, Martyn A1 - Anesio, Alexandre M. A1 - Benning, Liane G. T1 - Endometabolic profiling of pigmented glacier ice algae: the impact of sample processing N2 - Introduction Glacier ice algae, mainly Ancylonema alaskanum and Ancylonema nordenskiöldi, bloom on Greenland Ice Sheet bare ice surfaces. They significantly decrease surface albedo due to their purple-brown pigmentation, thus increasing melt. Little is known about their metabolic adaptation and factors controlling algal growth dynamics and pigment formation. A challenge in obtaining such data is the necessity of melting samples, which delays preservation and introduces bias to metabolomic analysis. There is a need to evaluate the physiological response of algae to melting and establish consistent sample processing strategies for metabolomics of ice microbial communities. Objectives To address the impact of sample melting procedure on metabolic characterization and establish a processing and analytical workflow for endometabolic profiling of glacier ice algae. Methods We employed untargeted, high-resolution mass spectrometry and tested the effect of sample melt temperature (10, 15, 20 °C) and processing delay (up to 49 h) on the metabolome and lipidome, and complemented this approach with cell counts (FlowCam), photophysiological analysis (PAM) and diversity characterization. Results and Conclusion We putatively identified 804 metabolites, with glycerolipids, glycerophospholipids and fatty acyls being the most prominent superclasses ( 50% of identified metabolites). Among the polar metabolome, carbohydrates and amino acid-derivatives were the most abundant. We show that 8% of the metabolome is affected by melt duration, with a pronounced decrease in betaine membrane lipids and pigment precursors, and an increase in phospholipids. Controlled fast melting at 10 °C resulted in the highest consistency, and is our recommendation for future supraglacial metabolomics studies. KW - Metabolic profiling KW - Mass Spectrometry KW - Ice algae PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-607921 DO - https://doi.org/10.1007/s11306-024-02147-6 VL - 20 IS - 5 SP - 1 EP - 15 PB - Springer Science and Business Media LLC AN - OPUS4-60792 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Plouffe, A. A1 - Lee, R. G. A1 - Byrne, K. A1 - Kjarsgaard, I. M. A1 - Petts, D. C. A1 - Wilton, D.H.C. A1 - Ferbey, T. A1 - Oelze, Marcus T1 - Tracing Detrital Epidote Derived from Alteration Halos to Porphyry Cu Deposits in Glaciated Terrains: The Search for Covered Mineralization N2 - Distal alteration related to porphyry Cu mineralization is typically characterized by an abundance of green minerals, such as epidote, tremolite, and chlorite, within the propylitic and sodic-calcic alteration zones and extends far outside (>1 km) the mineralized zone(s). Glacial erosion and dispersal derived from rocks affected by propylitic and sodic-calcic alteration have resulted in the development of extensive dispersal trains of epidote in till (glacial sediment) that can reach 8 to 330 km2 as observed at four porphyry Cu study sites in the Quesnel terrane of south-central British Columbia: Highland Valley Copper, Gibraltar, Mount Polley, and Woodjam deposits. At each of these sites, epidote is more abundant in heavy mineral concentrates of till collected directly over and down-ice from mineralization and associated alteration. Epidote grains in till with >0.6 ppm Sb and >8 ppm As (as determined by laser ablation-inductively coupled plasma-mass spectrometry) are attributed to a porphyry alteration provenance. There is a greater abundance of epidote grains with high concentrations of trace elements (>12 ppm Cu, >2,700 ppm Mn, >7 ppm Zn, and >37 ppm Pb) in each porphyry district com� pared to background regions. This trace element signature recorded in till epidote grains is heterogeneously distributed in these districts and is interpreted to reflect varying degrees of metal enrichment from a porphyry fluid source. Tracing the source of the epidote in the till (i.e., geochemically tying it to porphyry-related propy� litic and/or sodic-calcic alteration), coupled with porphyry vectoring tools in bedrock, will aid in the detection of concealed porphyry Cu mineralization in glaciated terrains. KW - Indicator minerals KW - Porphyry Cu deposits KW - Epidote KW - Glaciated terrains KW - Propylitic alteration PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-635209 DO - https://doi.org/10.5382/econgeo.5049 SN - 1554-0774 VL - 119 IS - 2 SP - 305 EP - 329 PB - Society of Economic Geologists, Inc. AN - OPUS4-63520 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ponader, Marco A1 - Röder, Bettina A1 - Paul, Martin A1 - Weller, Michael G. T1 - Sintered glass monoliths as supports for affinity columns N2 - A novel stationary phase for affinity separations is presented. This material is based on sintered borosilicate glass readily available as semi-finished filter plates with defined porosity and surface area. The material shows fast binding kinetics and excellent long-term stability under real application conditions due to lacking macropores and high mechanical rigidity. The glass surface can be easily modified with standard organosilane chemistry to immobilize selective binders or other molecules used for biointeraction. In this paper, the manufacturing of the columns and their respective column holders by 3D printing is shown in detail. The model system protein A/IgG was chosen as an example to examine the properties of such monolithic columns under realistic application conditions. Several specifications, such as (dynamic) IgG capacity, pressure stability, long-term performance, productivity, non-specific binding, and peak shape, are presented. It could be shown that due to the very high separation speed, 250 mg antibody per hour and column can be collected, which surpasses the productivity of most standard columns of the same size. The total IgG capacity of the shown columns is around 4 mg (5.5 mg/mL), which is sufficient for most tasks in research laboratories. The cycle time of an IgG separation can be less than 1 min. Due to the glass material’s excellent pressure resistance, these columns are compatible with standard HPLC systems. This is usually not the case with standard affinity columns, limited to manual use or application in low-pressure systems. The use of a standard HPLC system also improves the ability for automation, which enables the purification of hundreds of cell supernatants in one day. The sharp peak shape of the elution leads to an enrichment effect, which might increase the concentration of IgG by a factor of 3. The final concentration of IgG can be around 7.5 mg/mL without the need for an additional nano-filtration step. The purity of the IgG was > 95% in one step and nearly 99% with a second polishing run. KW - Affinity Chromatography KW - Affinity Extraction KW - Affinity Separation KW - Protein Purification KW - Down Stream Processing KW - Antibody Purification KW - Diagnostic Antibodies KW - Therapeutic Antibodies KW - Automated Purification KW - HPLC KW - FPLC KW - IgG determination KW - Concentration step KW - Monoclonal Antibodies KW - Polyclonal Antibodies KW - Human Plasma KW - Glass Support KW - Borosilicate Glass KW - Monolith KW - Sintered Material KW - Additive Manufacturing KW - Column holder KW - Construction KW - Open Science KW - Citizen Science KW - Protein A KW - Regeneration KW - High-Speed Separations KW - Robustness PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-527581 DO - https://doi.org/10.3390/separations8050056 SN - 2297-8739 N1 - Geburtsname von Ponader, Marco: Wilke, M. - Birth name of Ponader, Marco: Wilke, M. VL - 8 IS - 5 SP - 1 EP - 16 PB - MDPI CY - Basel AN - OPUS4-52758 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Potopnyk, M. A1 - Mech-Piskorz, J. A1 - Angulo, G. A1 - Ceborska, M. A1 - Luboradzki, R. A1 - Andresen, Elina A1 - Gajek, A. A1 - Wisniewska, A. A1 - Resch-Genger, Ute T1 - Aggregation/Crystallization-Induced Emission in Naphthyridine-Based Carbazolyl-Modified Donor-Acceptor Boron Dyes Tunable by Fluorine Atoms N2 - Four donor-acceptor boron difluoride complexes based on the carbazole electron donor and the [1,3,5,2]oxadiazaborinino[3,4-a][1,8]naphthyridine acceptor were designed, synthesized, and systematically spectroscopically investigated in solutions, in the solid states, and dye-doped polymer films. The dyes exhibit an intense blue to red solid-state emission with photoluminescence quantum yields of up to 56% in pure dye samples and 86% in poly(methyl methacrylate) films. All boron complexes show aggregation-induced emission and reversible mechanofluorochromism. The optical properties of these dyes and their solid state luminescence can be tuned by substitution pattern, i.e., the substituents at the naphthyridine unit. Exchange of CH3- for CF3-groups does not only increase the intramolecular charge transfer character, but also provides a crystallization-induced emission enhancement. KW - Spectroscopy KW - Dye KW - Luminescence KW - Sensor KW - Fluorescence KW - Quantum yield KW - Lifetime KW - Quality assurance KW - Synthesis PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597426 DO - https://doi.org/10.1002/chem.202400004 SN - 0947-6539 SP - 1 EP - 12 PB - Wiley VHC-Verlag AN - OPUS4-59742 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Prakash, Swayam A1 - Bell, Jérémy A1 - Rurack, Knut T1 - Rapid Onsite Detection of Fecal Contamination in Water Using a Portable Fluorometric Assay N2 - Fecal pollution in water poses significant health risks, especially when contaminated sources are used for drinking and food production. Traditional water quality testing methods are expensive, slow, and require skilled personnel, limiting their accessibility. This work addresses these issues by developing a portable fluorometric assay for the detection of the fecal indicator pigment urobilin (UB). The assay uses silane-functionalized glass fiber strips impregnated with zinc chloride, providing a ‘drop-&-detect’ approach with enhanced fluorescence response mediated by the unique complexation properties of ZnCl2 and UB. This approach allows for the detection of UB at sub-nanomolar concentrations in less than 1 min using a 3D-printed setup with miniaturized optical components powered by a smartphone with its camera as a detector. The results validated with a benchtop fluorometer show the effectiveness of this method. The successful application of this userfriendly, rapid, and sensitive assay to real water samples from three rivers and the influx and efflux of a wastewater treatment plant advances field-based water quality monitoring, meets the WHO’s ASSURED criteria, and supports progress toward the global clean water and sanitation goals. KW - Fecal pigment KW - Fluorescence KW - Signal amplification KW - Surface chemistry KW - Water quality testing PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655543 DO - https://doi.org/10.1021/acssensors.5c03922 SN - 2379-3694 VL - 11 SP - 1 EP - 9 PB - American Chemical Society CY - Washington, D.C. AN - OPUS4-65554 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Prohaska, T. A1 - Irrgeher, J. A1 - Benefield, J. A1 - Böhlke, J. K. A1 - Chesson, L. A. A1 - Coplen, T. B. A1 - Ding, T. A1 - Dunn, P. J. H. A1 - Gröning, M. A1 - Holden, N. E. A1 - Meijer, H. A. J. A1 - Moossen, H. A1 - Possolo, A. A1 - Takahashi, Y. A1 - Vogl, Jochen A1 - Walczyk, T. A1 - Wang, J. A1 - Wieser, M. E. A1 - Yoneda, S. A1 - Zhu, X.-K. A1 - Meija, J. T1 - Standard atomic weights of the elements 2021 (IUPAC Technical Report) N2 - Following the reviews of atomic-weight determinations and other cognate data in 2015, 2017, 2019 and 2021, the IUPAC (International Union of Pure and Applied Chemistry) Commission on Isotopic Abundances and Atomic Weights (CIAAW) reports changes of standard atomic weights. The symbol Ar(E) was selected for standard atomic weight of an element to distinguish it from the atomic weight of an element E in a specific substance P, designated Ar(E, P). The CIAAW has changed the values of the standard atomic weights of five elements based on recent determinations of terrestrial isotopic abundances: Ar (argon): from 39.948 ± 0.001 to [39.792, 39.963] Hf (hafnium): from 178.49 ± 0.02 to 178.486 ± 0.006 Ir (iridium): from 192.217 ± 0.003 to 192.217 ± 0.002 Pb (lead): from 207.2 ± 0.1 to [206.14, 207.94] Yb (ytterbium): from 173.054 ± 0.005 to 173.045 ± 0.010 The standard atomic weight of argon and lead have changed to an interval to reflect that the natural variation in isotopic composition exceeds the measurement uncertainty of Ar(Ar) and Ar(Pb) in a specific substance. The standard atomic weights and/or the uncertainties of fourteen elements have been changed based on the Atomic Mass Evaluations 2016 and 2020 accomplished under the auspices of the International Union of Pure and Applied Physics (IUPAP). Ar of Ho, Tb, Tm and Y were changed in 2017 and again updated in 2021: Al (aluminium), 2017: from 26.981 5385 ± 0.000 0007 to 26.981 5384 ± 0.000 0003 Au (gold), 2017: from 196.966 569 ± 0.000 005 to 196.966 570 ± 0.000 004 Co (cobalt), 2017: from 58.933 194 ± 0.000 004 to 58.933 194 ± 0.000 003 F (fluorine), 2021: from 18.998 403 163 ± 0.000 000 006 to 18.998 403 162 ± 0.000 000 005 (Ho (holmium), 2017: from 164.930 33 ± 0.000 02 to 164.930 328 ± 0.000 007) Ho (holmium), 2021: from 164.930 328 ± 0.000 007 to 164.930 329 ± 0.000 005 Mn (manganese), 2017: from 54.938 044 ± 0.000 003 to 54.938 043 ± 0.000 002 Nb (niobium), 2017: from 92.906 37 ± 0.000 02 to 92.906 37 ± 0.000 01 Pa (protactinium), 2017: from 231.035 88 ± 0.000 02 to 231.035 88 ± 0.000 01 Pr (praseodymium), 2017: from 140.907 66 ± 0.000 02 to 140.907 66 ± 0.000 01 Rh (rhodium), 2017: from 102.905 50 ± 0.000 02 to 102.905 49 ± 0.000 02 Sc (scandium), 2021: from 44.955 908 ± 0.000 005 to 44.955 907 ± 0.000 004 (Tb (terbium), 2017: from 158.925 35 ± 0.000 02 to 158.925 354 ± 0.000 008) Tb (terbium), 2021: from 158.925 354 ± 0.000 008 to 158.925 354 ± 0.000 007 (Tm (thulium), 2017: from 168.934 22 ± 0.000 02 to 168.934 218 ± 0.000 006) Tm (thulium), 2021: from 168.934 218 ± 0.000 006 to 168.934 219 ± 0.000 005 (Y (yttrium), 2017: from 88.905 84 ± 0.000 02 to 88.905 84 ± 0.000 01) Y (yttrium), 2021: from 88.905 84 ± 0.000 01 to 88.905 838 ± 0.000 002 KW - Argon KW - Ciaaw.org KW - Hafnium KW - Iridium KW - Lead KW - LSVEC KW - Ytterbium PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-548443 DO - https://doi.org/10.1515/pac-2019-0603 SN - 0033-4545 VL - 94 IS - 5 SP - 573 EP - 600 PB - De Gruyter Verlag CY - Berlin AN - OPUS4-54844 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pätzold, Stefan A1 - Ostermann, Markus A1 - Heggemann, Tobias A1 - Wehrle, Ralf T1 - Impact of potassium fertilisation on mobile proximal gamma-ray spectrometry: case study on a long-term field trial N2 - Mobile proximal gamma-ray spectrometry (GS) is an emerging approach to estimate soil texture directly in the field. It relies on gamma radiation emitted during the natural decay of potassium-40 (K-40) and other isotopes. The K-40 counts are correlated with total K content, mineralogical soil composition and therefore with soil texture. Yet, it is not clear if K fertilisation impacts the ratio of K-40 to total K which would necessitate to take the fertilisation history into account for soil sensing applications. To elucidate this question, a well-documented long-term experiment was selected. The soils of the Rengen grassland experiment (55 plots) were investigated for total K (XRF-K) and for K-40 via mobile proximal GS. No significant differences in XRF-K and K-40 were found between the treatments with and without K fertilisation, although formely published results point to negative and positive K balances, respectively. Fertiliser analysis revealed a ratio of K-40 to total K that was almost identical to the natural abundance of 0.0117%. It was concluded that it is not necessary to take K fertilisation history into account when predicting soil texture from mobile proximal GS on agricultural land for, e.g., precision farming purposes. KW - Soil heterogeneity KW - Potash KW - Isotope ratio KW - Proximal soil sensing KW - XRF PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-584115 DO - https://doi.org/10.1007/s11119-023-10071-3 SN - 1573-1618 SP - 1 EP - 11 PB - Springer Nature CY - Berlin AN - OPUS4-58411 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Quackatz, Lukas A1 - Gornushkin, Igor B. A1 - Griesche, Axel A1 - Kannengießer, Thomas A1 - Treutler, Kai A1 - Wesling, Volker T1 - In situ chemical analysis of duplex stainless steel weld by laser induced breakdown spectroscopy N2 - The high corrosion resistance and good mechanical properties of duplex stainless steel (DSS) are due to its special chemical composition, which is a balanced phase ratio of ferrite (α) and austenite (γ). Many industrial applications require the integration of DSS components. For this, Gas tungsten arc welding (GTAW) is an excellent choice, as it allows an automated operation with high reproducibility. However, when the weld pool solidifies, critical ratios of α- and γ- phases can occur, which lead to solidification cracking, increased susceptibility to corrosion, and a decrease in ductility and critical strength. Previous studies have shown that these defects can be caused by the accumulation of manganese and chromium in the heat affected zone (HAZ), requiring ongoing monitoring of this accumulation. A suitable method for such monitoring is laser-induced breakdown spectroscopy (LIBS), which can be used in two operating modes: calibration using standard reference samples and calibration-free. Unlike conventional quantitative LIBS measurements, which require reference samples to generate a calibration curve, calibration-free LIBS (CF-LIBS) allows chemical compositions to be determined solely from the emission spectrum of the plasma. Numerous publications show that CF-LIBS is a fast and efficient analytical method for the quantitative analysis of metal samples. In this work, CF-LIBS is applied to spectra obtained during GTAW DSS welding and the result is compared with those obtained by PLS analysis. A good correlation was found between both types of analysis, demonstrating the suitability of the CF-LIBS method for this application. The CF-LIBS method has a significant advantage over conventional LIBS due to the rapid in situ measurement of concentrations of major alloying elements without calibration procedure. This, combined with fast feedback and appropriate adjustment of welding parameters, helps prevent welding defects. KW - Duplex stainless steels KW - In situ measurement KW - LIBS KW - GMAW PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597940 DO - https://doi.org/10.1016/j.sab.2024.106899 SN - 0584-8547 VL - 214 SP - 1 EP - 7 PB - Elsevier B.V. AN - OPUS4-59794 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Radnik, Jörg A1 - Knigge, Xenia A1 - Andresen, Elina A1 - Resch-Genger, Ute A1 - Cant, D.J.H. A1 - Shard, A.G. A1 - Clifford, C.A. T1 - Composition, thickness, and homogeneity of the coating of core–shell nanoparticles—possibilities, limits, and challenges of X-ray photoelectron spectroscopy N2 - Core–shell nanoparticles have attracted much attention in recent years due to their unique properties and their increasing importance in many technological and consumer products. However, the chemistry of nanoparticles is still rarely investigated in comparison to their size and morphology. In this review, the possibilities, limits, and challenges of X-ray photoelectron spectroscopy (XPS) for obtaining more insights into the composition, thickness, and homogeneity of nanoparticle coatings are discussed with four examples: CdSe/CdS quantum dots with a thick coating and a small core; NaYF4-based upconverting nanoparticles with a large Yb-doped core and a thin Er-doped coating; and two types of polymer nanoparticles with a poly(tetrafluoroethylene) core with either a poly(methyl methacrylate) or polystyrene coating. Different approaches for calculating the thickness of the coating are presented, like a simple numerical modelling or a more complex simulation of the photoelectron peaks. Additionally, modelling of the XPS background for the investigation of coating is discussed. Furthermore, the new possibilities to measure with varying excitation energies or with hard-energy X-ray sources (hard-energy X-ray photoelectron spectroscopy) are described. A discussion about the sources of uncertainty for the determination of the thickness of the coating completes this review. KW - X-ray spectroscopy KW - Nanoparticles KW - Spectroscopy / Instrumentation KW - Spectroscopy / Theory PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-548305 DO - https://doi.org/10.1007/s00216-022-04057-9 VL - 414 IS - 15 SP - 4331 EP - 4345 PB - SpringerNature AN - OPUS4-54830 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Raysyan, Anna A1 - Moerer, R. A1 - Coesfeld, Bianca A1 - Eremin, S. A1 - Schneider, Rudolf T1 - Fluorescence polarization immunoassay for the determination of diclofenac in wastewater N2 - Pharmacologically active compounds are often detected in wastewater and surface waters. The nonsteroidal anti-inflammatory drug diclofenac (DCF) was included in the European watch list of substances that requires its environmental monitoring in the member states. DCF may harmfully influence the ecosystem already at concentrations ≤ 1 μg L−1. The fast and easy quantification of DCF is becoming a subject of global importance. Fluorescence polarization immunoassay (FPIA) is a homogeneous mix-and-read method which does not require the immobilization of reagents. FPIA can be performed in one phase within 20–30 min, making it possible to analyse wastewater without any complicated pre-treatment. In this study, new tracermolecules with different structures, linking fluorophores to derivatives of the analyte, were synthesized, three homologous tracers based on DCF, two including a C6 spacer, and one heterologous tracer derived from 5-hydroxy-DCF. The tracer molecules were thoroughly assessed for performance. Regarding sensitivity of the FPIA, the lowest limit of detection reached was 2.0 μg L−1 with a working range up to 870 μg L−1. The method was validated for real wastewater samples against LC-MS/MS as reference method with good agreement of both methods. KW - Abwasser KW - Umweltschadstoffe KW - Antikörper KW - Antibody PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-518398 DO - https://doi.org/10.1007/s00216-020-03058-w SN - 1618-2642 VL - 413 IS - 4 SP - 999 EP - 107 PB - Springer CY - Heidelberg AN - OPUS4-51839 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Raysyan, Anna A1 - Schneider, Rudolf T1 - Development of a Lateral Flow Immunoassay (LFIA) to Screen for the Release of the Endocrine Disruptor Bisphenol A from Polymer Materials and Products N2 - One of the most important chemicals used in the production of polymer plastics and coatings is bisphenol A. However, despite the large number of studies on the toxicity and hormonal activity of BPA, there are still open questions and thus considerable media attention regarding BPA toxicity. Hence, it is necessary to develop a sensitive, simple, cost-efficient, specific, portable, and rapid method for monitoring bisphenol A and for high sample throughput and on-site screening analysis. Lateral flow immunoassays have potential as rapid tests for on-site screening. To meet sensitivity criteria, they must be carefully optimized. A latex microparticle-based LFIA for detection of BPA was developed. The sensitivity of the assay was improved by non-contact printing of spot grids as the control and test lines with careful parameter optimization. Results of the test could be visually evaluated within 10 min with a visual cut-off of 10 µg/L (vLOD). Alternatively, photographs were taken, and image analysis performed to set up a calibration, which allowed for a calculated limit of detection (cLOD) of 0.14 µg/L. The method was validated for thermal paper samples against ELISA and LC–MS/MS as reference methods, showing good agreement with both methods KW - Endokrine Disruptoren KW - Polymere KW - Schnelltest KW - Endocrine disruptor KW - Bisphenol A KW - LFIA KW - Immunoassay PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-540492 DO - https://doi.org/10.3390/bios11070231 VL - 11 IS - 7 SP - 1 EP - 11 PB - MDPI CY - Basel AN - OPUS4-54049 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -