TY - JOUR A1 - Xue, Boyang A1 - Wang, Zhangjun A1 - Zhu, Tao A1 - Gu, Yezhen A1 - Sun, Weihong A1 - Chen, Chao A1 - Li, Zhigang A1 - Riedel, Jens A1 - You, Yi T1 - High repetition-rate laser-induced breakdown spectroscopy combined with two-dimensional correlation method for analysis of sea-salt aerosols N2 - Laser-induced breakdown spectroscopy (LIBS) offers a tantalizing glimpse into real-time, on-the-spot aerosol analysis. Yet, the reliance on traditional lasers, with their limitations in energy and frequency, hampers optimal sample handling, dissociation, and excitation. To address those challenges, we propose a novel tactic: utilize a high repetition-rate (rep.-rate) laser with low pulse energy in combination with the two-dimensional correlation (2D-corr.) technique for sea-salt aerosols analyses. By examining the emission patterns from both the laser pulse train and individual pulses, we recognize distinctive analyte-specific rep.-rate responses, which allowed spectral reconstruction of analytes, avoiding background interferences. This discovery enabled the rep.-rate modulation for a 2D-corr. spectroscopy workflow. Consequently, we successfully differentiated between particle-related and air-species-related spectral components, obviating expensive spectrometers or intensified image detectors. For instance, the Na I at 589 nm stemming from aerosols exhibited an entirely different correlation contribution compared to O I at 777 nm, resulting in reconstructed clean aerosol-spectra without spectral peaks originated from air species. This 2D-corr. aerosol LIBS approach shows promising analytical potential streamlining aerosol particle analysis. KW - LIBS KW - Aerosol PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-613392 DO - https://doi.org/10.1016/j.sab.2024.107048 SN - 0584-8547 VL - 221 SP - 1 EP - 8 PB - Elsevier AN - OPUS4-61339 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wittwer, Philipp A1 - Roesch, Philipp A1 - Vogel, Christian A1 - Simon, Fabian A1 - Gehrenkemper, Lennart A1 - Feldmann, Ines A1 - Simon, Franz-Georg T1 - Less Is More: Influence of Cross-Linking Agent Concentration on PFOS Adsorption in Chitosan N2 - As a result of the continuous use of persistent per- and polyfluoroalkyl substances (PFAS), e.g., in aviation firefighting foams, contamination with PFAS has been found in soil, groundwater, and surface water around thousands of industrial and military installations. Due to their harmful (environmental) potential, further dispersion in the environment needs to be stopped, which can be achieved by appropriate absorption materials. In this work, the influence of the cross-linking agent epichlorohydrin (ECH) concentration on the perfluorooctanesulfonic acid (PFOS) adsorption capacity of chitosan gel was investigated. It was found that higher ECH concentration during the cross-linking step decreases the PFOS adsorption capacity of the cross-linked chitosan gel from 0% to 4% ECH solution by about 15%. Using a concentration of 1%, ECH resulted still in an acid-stable material, and a maximum PFOS loading capacity of 4.04 mmol/g was obtained, one of the highest described in the literature. Furthermore, we used a rapid small-scale column test to compare the PFOS adsorption capacity of chitosan and activated carbon, each in both milled and unmilled form. Unmilled chitosan showed the highest PFOS adsorption capacity considering adsorption material dry masses (>0.9 and <0.4 mmol/g for both types of chitosan and activated carbon, respectively). Milled activated carbon proved to be the better adsorption material, considering the fixed volume of the adsorber (>99.9% PFOS adsorbed). Overall, the cross-linking agent concentration in chitosan is a crucial factor influencing its PFOS absorption potential. Our results feature cross-linked chitosan as an effective economic and ecologic alternative for PFOS adsorption in aqueous solutions. KW - Combustion Ion Chromatography KW - Per- and Polyfluoroalkyl substances (PFAS) KW - Remediation PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-618406 DO - https://doi.org/10.3390/app142311145 VL - 14 IS - 23 SP - 1 EP - 13 PB - MDPI AN - OPUS4-61840 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wen, Keqing A1 - Gorbushina, Anna A1 - Schwibbert, Karin A1 - Bell, Jérémy T1 - Microfluidic platform with precisely controlled hydrodynamic parameters and integrated features for generation of microvortices to accurately form and monitor biofilms in flow N2 - Microorganisms often live in habitats characterized by fluid flow, and their adhesion to surfaces in industrial systems or clinical settings may lead to pipe clogging, microbially influenced corrosion, material deterioration, food spoilage, infections, and human illness. Here, a novel microfluidic platform was developed to investigate biofilm formation under precisely controlled (i) cell concentration, (ii) temperature, and (iii) flow conditions. The developed platform central unit is a single-channel microfluidic flow cell designed to ensure ultrahomogeneous flow and condition in its central area, where features, e.g., with trapping properties, can be incorporated. In comparison to static and macroflow chamber assays for biofilm studies, microfluidic chips allow in situ monitoring of biofilm formation under various flow regimes and have better environment control and smaller sample requirements. Flow simulations and experiments with fluorescent particles were used to simulate bacteria flow in the platform cell for calculating flow velocity and direction at the microscale level. The combination of flow analysis and fluorescent strain injection in the cell showed that microtraps placed at the center of the channel were efficient in capturing bacteria at determined positions and to study how flow conditions, especially microvortices, can affect biofilm formation. The microfluidic platform exhibited improved performances in terms of homogeneity and robustness for in vitro biofilm formation. We anticipate the presented platform to be suitable for broad, versatile, and high-throughput biofilm studies at the microscale level. KW - Topographical pattern KW - E. coli KW - Fluorescence KW - Bacteria trapping KW - Particle velocimetry PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-610450 DO - https://doi.org/10.1021/acsbiomaterials.4c00101 SN - 2373-9878 VL - 10 IS - 7 SP - 4626 EP - 4634 PB - ACS Publ. CY - Washington, DC AN - OPUS4-61045 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wetzel, Annica A1 - Morell, Daniel A1 - von der Au, Marcus A1 - Wittstock, Gunther A1 - Özcan Sandikcioglu, Özlem A1 - Witt, Julia T1 - Transpassive Metal Dissolution vs. Oxygen Evolution Reaction: Implication for Alloy Stability and Electrocatalysis T1 - Transpassive Metallauflösung vs. Sauerstoffentwicklung: Auswirkungen auf Legierungsstabilität und Elektrokatalyse N2 - Multi-principal element alloys (MPEAs) are gaining interest in corrosion and electrocatalysis research due to their electrochemical stability across a broad pH range and the design flexibility they offer. Using the equimolar CrCoNi alloy, we observe significant metal dissolution in a corrosive electrolyte (0.1 M NaCl, pH 2) concurrently with the oxygen evolution reaction (OER) in the transpassive region despite the absence of hysteresis in polarization curves or other obvious corrosion indicators. We present a characterization scheme to delineate the contribution of OER and alloy dissolution, using scanning electrochemical microscopy (SECM) for OER-onset detection, and quantitative chemical analysis with inductively coupled-mass spectrometry (ICP-MS) and ultraviolet visible light (UV-Vis) spectroscopy to elucidate metal dissolution processes. In-situ electrochemical atomic force microscopy (EC-AFM) revealed that the transpassive metal dissolution on CrCoNi is dominated by intergranular corrosion. These results have significant implications for the stability of MPEAs in corrosion systems, emphasizing the necessity of analytically determining metal ions released from MPEA electrodes into the electrolyte when evaluating Faradaic efficiencies of OER catalysts. The release of transition metal ions not only reduces the Faradaic efficiency of electrolyzers but may also cause poisoning and degradation of membranes in electrochemical reactors. N2 - Multi-Hauptelement-Legierungen (MPEAs) gewinnen in der Korrosions- und Elektrokatalyseforschung aufgrund ihrer elektrochemischen Stabilität über einen breiten pH-Bereich und der Vielfalt der möglichen chemischen Zusammensetzungen zunehmend an Interesse. In unseren Untersuchungen mit der äquimolaren CrCoNi-Legierung in einem sauren Elektrolyten (0.1 M NaCl, pH 2) beobachteten wir eine signifikante Metallauflösung, die mit der Sauerstoffentwicklungsreaktion (OER) im transpassiven Bereich einhergeht, obwohl in zyklischen Polarisationskurven keine Hysterese auftrat oder andere offensichtliche Korrosionsindikatoren vorlagen. In diesem Artikel wird ein Charakterisierungskonzept eingeführt, dass die Beiträge der OER und der Legierungsauflösung differenziert. Hierfür kommt die elektrochemische Rastermikroskopie (SECM) zum Nachweis des Beginns der OER und die quantitative chemische Analyse mit induktiv gekoppelter Massenspektrometrie (ICP-MS) und UV/Vis-Spektrometrie zur Aufklärung der Metallauflösungsprozesse zum Einsatz. Die elektrochemische In situ-Atomkraftmikroskopie (EC-AFM) zeigte, dass die intergranulare Korrosion der dominierende Mechanismus der transpassive Metallauflösung von CrCoNi ist. Diese Ergebnisse besitzen erhebliche Auswirkungen für die Beurteilung der Stabilität von MPEAs in Korrosionssystemen und der Stromausbeute von OER-Katalysatoren auf der Basis von MPEAs. Die Daten unterstreichen die Notwendigkeit der analytischen Bestimmung von Metallionen, die von MPEA-Elektroden freigesetzt werden. Die Freisetzung von Übergangsmetallionen verringert nicht nur die Stromausbeute von Elektrolyseuren, sondern kann zu einer Schädigung von Membranen in elektrochemischen Reaktoren führen. KW - Transpassive dissolution KW - Corrosion KW - Multi-prinicpal element alloys (MPEAs) KW - Passivation PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597045 DO - https://doi.org/10.1002/anie.202317058 SP - 1 EP - 8 PB - Wiley VHC-Verlag AN - OPUS4-59704 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grimmer, Christoph A1 - Richter, Matthias A1 - Neuhaus, T. A1 - Prinz, Carsten A1 - Strzelczyk, Rebecca Skadi A1 - Colakoglu, Irem A1 - Horn, Wolfgang T1 - Towards a multi-VOC emission reference material with temporally constant emission profile for QA/QC of materials emission testing procedures N2 - Emission reference materials (ERMs) are sought after to further control and improve indoor air quality. The impregnation of porous materials with volatile organic compounds (VOCs) is a promising approach to produce ERMs. Different VOCs were used to impregnate various porous materials (mainly zeolites, activated carbons and a metal organic framework). The influence of different methodological parameters and material properties were studied to optimize the impregnation procedure and to find the best material/VOC combination. The impregnation procedure remains quite irreproducible, nevertheless, very good ERM candidates were identified. Two materials (zeolite 4 and AC 1 impregnated with n-hexadecane) showed a very stable emission over 14 days (<10 % change). Another material (AC 1 impregnated with toluene) showed a declining emission profile but with a very good in-batch reproducibility and a storage stability of up to 12 months. KW - Emission reference material KW - Porous materials KW - Indoor air quality KW - Emission test chamber KW - CO2 assisted impregnation KW - EN 16516 PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-612238 DO - https://doi.org/10.1016/j.chemosphere.2024.143437 SN - 1879-1298 VL - 366 SP - 1 EP - 8 PB - Elsevier AN - OPUS4-61223 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scholl, Juliane A1 - Lisec, Jan A1 - Haase, Hajo A1 - Koch, Matthias T1 - Identification of transformation products from fluorinated lithium-ion battery additives TPFPB and TPFPP: forever chemicals of tomorrow? N2 - AbstractFluorinated organic compounds (FOCs) represent a class of synthetic chemicals distinguished by their resilient carbon–fluorine bonds, which demonstrate an ability to withstand environmental degradation over an extended period. The integration of FOCs into cutting-edge applications, including lithium-ion batteries (LiBs), presents considerable potential for environmental harm that has not yet been sufficiently addressed. This study focuses on the environmental fate of two fluorinated aromatics, tris(pentafluorophenyl)borane (TPFPB) and tris(pentafluorophenyl)phosphine (TPFPP), given their important role in improving the performance of LiBs. To achieve this, laboratory simulation methods including total oxidizable precursor assay, electrochemistry (EC), Fenton reaction, UV-C irradiation, and hydrolysis were employed. Liquid chromatography and gas chromatography coupled with high-resolution mass spectrometry were used for identification of transformation products (TPs) and prediction of their molecular formulae. Despite the structural similarity between TPFPB and TPFPP, distinct differences in electrochemical behavior and degradation pathways were observed. TPFPB readily underwent hydroxylation and hydrolysis, resulting in a wide range of 49 TPs. A total of 28 TPs were newly identified, including oligomers and highly toxic dioxins. In contrast, TPFPP degraded exclusively under harsh conditions, requiring the development of innovative conditioning protocols for EC. In total, the simulation experiments yielded nine structurally different compounds, including seven previously undescribed, partially defluorinated TPs. This study highlights the potential risks associated with the use of FOCs in LiBs and provides insight into the complex environmental behavior of FOCs. KW - Mass Spectrometry KW - LiBs KW - POPs KW - Transformation products KW - Electrochemistry PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-611339 DO - https://doi.org/10.1007/s00216-024-05526-z SP - 1 EP - 15 PB - Springer Science and Business Media LLC AN - OPUS4-61133 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wetzel, Annica A1 - Morell, Daniel A1 - von der Au, Marcus A1 - Witt, Julia A1 - Özcan Sandikcioglu, Özlem T1 - Transpassive Behavior of Equimolar CrMnFeCoNi and CrCoNi Multi‐Principal Element Alloys in an Alkaline NaCl Electrolyte N2 - AbstractWe investigated the corrosion properties and transpassive behavior of CrMnFeCoNi and CrCoNi multi‐principal element alloys (MPEAs) in a 0.1 M NaCl electrolyte at pH 12. By using SECM‐based tip substrate voltammetry (TSV) in combination with the chemical analysis of the electrolyte, we were able to differentiate between anodic metal dissolution and oxygen evolution in the transpassive range. Our investigations have shown that CrCoNi has a significantly higher corrosion resistance compared to CrMnFeCoNi. In the studied alkaline environment, a transpassive oxide film is formed on the surface of CrCoNi during secondary passivation. This transpassive oxide film appears to play a significant role in oxygen evolution, as the increase in TSV currents at the microelectrode coincides with the corresponding current density plateau of the voltametric current trace. The formation of the transpassive oxide film was not observed in previous studies conducted in acidic environments. Moreover, the alkaline electrolyte induced a positive hysteresis and mild pitting corrosion, in addition to intergranular corrosion, which was the sole corrosion process observed at acidic pH levels. These findings enhance the understanding of the processes governing the transpassivity of CrMnFeCoNi and CrCoNi MPEAs in alkaline environments and have potential implications for the development of application‐tailored corrosion‐resistant MPEAs. KW - Multi-principal element alloys KW - MPEA KW - Corrosion KW - Oxygen evolution reaction KW - Transpassive region PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-611594 DO - https://doi.org/10.1002/celc.202400346 SN - 2196-0216 SP - 1 EP - 9 PB - Wiley AN - OPUS4-61159 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hülagü, Deniz A1 - Tobias, Charlie A1 - Dao, Radek A1 - Komarov, Pavel A1 - Rurack, Knut A1 - Hodoroaba, Vasile-Dan T1 - Towards 3D determination of the surface roughness of core–shell microparticles as a routine quality control procedure by scanning electron microscopy N2 - AbstractRecently, we have developed an algorithm to quantitatively evaluate the roughness of spherical microparticles using scanning electron microscopy (SEM) images. The algorithm calculates the root-mean-squared profile roughness (RMS-RQ) of a single particle by analyzing the particle’s boundary. The information extracted from a single SEM image yields however only two-dimensional (2D) profile roughness data from the horizontal plane of a particle. The present study offers a practical procedure and the necessary software tools to gain quasi three-dimensional (3D) information from 2D particle contours recorded at different particle inclinations by tilting the sample (stage). This new approach was tested on a set of polystyrene core-iron oxide shell-silica shell particles as few micrometer-sized beads with different (tailored) surface roughness, providing the proof of principle that validates the applicability of the proposed method. SEM images of these particles were analyzed by the latest version of the developed algorithm, which allows to determine the analysis of particles in terms of roughness both within a batch and across the batches as a routine quality control procedure. A separate set of particles has been analyzed by atomic force microscopy (AFM) as a powerful complementary surface analysis technique integrated into SEM, and the roughness results have been compared. KW - Core–shell particles KW - Image analysis KW - Roughness KW - Scanning electron microscopy KW - Atomic force microscopy KW - Tilting KW - Batch analysis PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-607590 DO - https://doi.org/10.1038/s41598-024-68797-7 SN - 2045-2322 VL - 14 IS - 1 SP - 1 EP - 13 PB - Springer Science and Business Media LLC AN - OPUS4-60759 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 - Zhang, Kun A1 - Carrod, Andrew J. A1 - Del Giorgio, Elena A1 - Hughes, Joseph A1 - Rurack, Knut A1 - Bennet, Francesca A1 - Hodoroaba, Vasile-Dan A1 - Harrad, Stuart A1 - Pikramenou, Zoe T1 - Luminescence Lifetime-Based Sensing Platform Based on Cyclometalated Iridium(III) Complexes for the Detection of Perfluorooctanoic Acid in Aqueous Samples N2 - Luminescence lifetimes are an attractive analytical method for detection due to its high sensitivity and stability. Iridium probes exhibit luminescence with long excited-state lifetimes, which are sensitive to the local environment. Perfluorooctanoic acid (PFOA) is listed as a chemical of high concern regarding its toxicity and is classified as a “forever chemical”. In addition to strict limits on the presence of PFOA in drinking water, environmental contamination from industrial effluent or chemical spills requires rapid, simple, accurate, and cost-effective analysis in order to aid containment. Herein, we report the fabrication and function of a novel and facile luminescence sensor for PFOA based on iridium modified on gold surfaces. These surfaces were modified with lipophilic iridium complexes bearing alkyl chains, namely, IrC6 and IrC12, and Zonyl-FSA surfactant. Upon addition of PFOA, the modified surfaces IrC6-FSA@Au and IrC12-FSA @Au show the largest change in the red luminescence signal with changes in the luminescence lifetime that allow monitoring of PFOA concentrations in aqueous solutions. The platform was tested for the measurement of PFOA in aqueous samples spiked with known concentrations of PFOA and demonstrated the capacity to determine PFOA at concentrations >100 μg/L (240 nM). KW - Perfluorooctanoic Acid (PFOA) KW - Cyclometalated iridium (III) complexes KW - Luminescent lifetime KW - Optically active surfaces KW - ToF-SIMS PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-594535 UR - https://pubs.acs.org/doi/10.1021/acs.analchem.3c04289 DO - https://doi.org/10.1021/acs.analchem.3c04289 VL - 96 IS - 4 SP - 1565 EP - 1575 PB - American Chemical Society (ACS) AN - OPUS4-59453 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Junge, Florian A1 - Wittwer, Philipp A1 - Sommerfeld, Thomas A1 - Gehrenkemper, Lennart A1 - Zoister, Christian A1 - Nickl, Philip A1 - Koch, Matthias A1 - Meermann, Björn A1 - Haag, Rainer T1 - Adsorber Charge Dominates over Hydrophobic or Fluorophilic Functionalization in Influencing Adsorption of PFCA onto Polystyrene Resins N2 - A systematic series of industrial-relevant polystyrene-based anion exchange resins that are functionalized with hydro- or fluorocarbon chains are compared regarding their adsorption behavior toward perfluorocarboxylic acids (PFCA) in respect to their charge, chain length, and type of chain. The results clearly show the dominance of electrostatic interactions in the adsorption process as uncharged adsorber materials showed no adsorption at all. In contrast, the charged adsorber materials showed in general a PFCA removal of 80% to 30% over the experiment depending on effluent fraction. Unexpectedly, for perfluorobutanoic acid (PFBA) the highest removal rate is found with consistently >90%. Despite observing significant benefits in the adsorption of PFCA for fluoroalkylated adsorbers in comparison to their non-fluorinated counterparts, this effect of fluoroalkylation is comparatively small and can not be clearly attributed to fluorophilic interactions between the fluoroalkyl chains. These findings help clarifying that the introduction of fluorocarbon moieties in adsorber materials is not necessary in order to remove fluorocarbon molecules from the environment. KW - PFAS KW - Remediation KW - Adsorption KW - Fluorophilic interactions PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601883 DO - https://doi.org/10.1002/admi.202400199 SN - 2196-7350 SP - 1 EP - 10 PB - John Wiley & Sons CY - Hoboken, New Jersey, USA AN - OPUS4-60188 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 - Bosc-Bierne, Gaby A1 - Ewald, Shireen A1 - Kreuzer, Oliver J. A1 - Weller, Michael G. T1 - Efficient Quality Control of Peptide Pools by UHPLC and Simultaneous UV and HRMS Detection N2 - Peptide pools consist of short amino acid sequences and have proven to be versatile tools in various research areas in immunology and clinical applications. They are commercially available in many different compositions and variants. However, unlike other reagents that consist of only one or a few compounds, peptide pools are highly complex products which makes their quality control a major challenge. Quantitative peptide analysis usually requires sophisticated methods, in most cases isotope-labeled standards and reference materials. Usually, this would be prohibitively laborious and expensive. Therefore, an approach is needed to provide a practical and feasible method for quality control of peptide pools. With insufficient quality control, the use of such products could lead to incorrect experimental results, worsening the well-known reproducibility crisis in the biomedical sciences. Here we propose the use of ultra-high performance liquid chromatography (UHPLC) with two detectors, a standard UV detector at 214 nm for quantitative analysis and a high-resolution mass spectrometer (HRMS) for identity confirmation. To be cost-efficient and fast, quantification and identification are performed in one chromatographic run. An optimized protocol is shown, and different peak integration methods are compared and discussed. This work was performed using a peptide pool known as CEF advanced, which consists of 32 peptides derived from cytomegalovirus (CMV), Epstein–Barr virus (EBV) and influenza virus, ranging from 8 to 12 amino acids in length. N2 - Peptidpools bestehen aus kurzen Aminosäuresequenzen und haben sich als vielseitige Werkzeuge in verschiedenen Forschungsbereichen der Immunologie und bei klinischen Anwendungen erwiesen. Sie sind in vielen verschiedenen Zusammensetzungen und Varianten im Handel erhältlich. Im Gegensatz zu anderen Reagenzien, die nur aus einer oder wenigen Verbindungen bestehen, sind Peptidpools jedoch hochkomplexe Produkte, was ihre Qualitätskontrolle zu einer großen Herausforderung macht. Die quantitative Peptidanalyse erfordert in der Regel ausgefeilte Methoden, in den meisten Fällen isotopenmarkierte Standards und Referenzmaterialien. Dies ist in der Regel sehr aufwändig und teuer. Daher wird ein Ansatz benötigt, der eine praktische und praktikable Methode zur Qualitätskontrolle von Peptidpools bietet. Bei unzureichender Qualitätskontrolle könnte die Verwendung solcher Produkte zu falschen Versuchsergebnissen führen, was das bekannte Problem der Reproduzierbarkeit in den biomedizinischen Wissenschaften noch verschärfen würde. Hier schlagen wir die Verwendung der Ultrahochleistungs-Flüssigkeitschromatographie (UHPLC) mit zwei Detektoren vor, einem Standard-UV-Detektor bei 214 nm für die quantitative Analyse und einem hochauflösenden Massenspektrometer (HRMS) für die Identitätsbestätigung. Um kosteneffizient und schnell zu sein, werden Quantifizierung und Identifizierung in einem einzigen chromatographischen Lauf durchgeführt. Es wird ein optimiertes Protokoll gezeigt, und es werden verschiedene Peak-Integrationsmethoden verglichen und diskutiert. Für diese Arbeit wurde ein Peptidpool verwendet, der als CEF advanced bekannt ist und aus 32 Peptiden besteht, die vom Cytomegalovirus (CMV), Epstein-Barr-Virus (EBV) und Influenzavirus stammen und zwischen 8 und 12 Aminosäuren lang sind. KW - Synthetic peptides KW - Quality control KW - Impurites KW - Byproducts KW - Degradation KW - Mass spectrometry KW - Orbitrap PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-602299 DO - https://doi.org/10.3390/separations11050156 SN - 2297-8739 VL - 11 IS - 5 SP - 1 EP - 18 PB - MDPI CY - Basel AN - OPUS4-60229 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weller, Michael G. T1 - The mystery of homochirality on earth N2 - Homochirality is an obvious feature of life on Earth. On the other hand, extraterrestrial samples contain largely racemic compounds. The same is true for any common organic synthesis. Therefore, it has been a perplexing puzzle for decades how these racemates could have formed enantiomerically enriched fractions as a basis for the origin of homochiral life forms. Numerous hypotheses have been put forward as to how preferentially homochiral molecules could have formed and accumulated on Earth. In this article, it is shown that homochirality of the abiotic organic pool at the time of formation of the first self-replicating molecules is not necessary and not even probable. It is proposed to abandon the notion of a molecular ensemble and to focus on the level of individual molecules. Although the formation of the first self-replicating, most likely homochiral molecule, is a seemingly improbable event, on a closer look, it is almost inevitable that some homochiral molecules have formed simply on a statistical basis. In this case, the non-selective leap to homochirality would be one of the first steps in chemical evolution directly out of a racemic “ocean”. Moreover, most studies focus on the chirality of the primordial monomers with respect to an asymmetric carbon atom. However, any polymer with a minimal size that allows folding to a secondary structure would spontaneously lead to asymmetric higher structures (conformations). Most of the functions of these polymers would be influenced by this inherently asymmetric folding. Furthermore, a concept of physical compartmentalization based on rock nanopores in analogy to nanocavities of digital immunoassays is introduced to suggest that complex cell walls or membranes were also not required for the first steps of chemical evolution. To summarize, simple and universal mechanisms may have led to homochiral self-replicating systems in the context of chemical evolution. A homochiral monomer pool is deemed unnecessary and probably never existed on primordial Earth. N2 - Homochiralität ist ein offensichtliches Merkmal des Lebens auf der Erde. Andererseits enthalten extraterrestrische Proben überwiegend racemische Verbindungen. Dasselbe gilt für jede gängige organische Synthese. Daher war es jahrzehntelang ein Rätsel, wie diese Racemate enantiomeren-angereicherte Fraktionen als Grundlage für den Ursprung homochiraler Lebensformen bilden konnten. Zahlreiche Hypothesen wurden aufgestellt, wie sich bevorzugt homochirale Moleküle auf der Erde gebildet und angereichert haben könnten. In diesem Artikel wird gezeigt, dass Homochiralität des abiotischen organischen Pools zum Zeitpunkt der Bildung der ersten selbstreplizierenden Moleküle nicht notwendig und nicht einmal wahrscheinlich ist. Es wird vorgeschlagen, die Vorstellung eines molekularen Ensembles aufzugeben und sich auf die Ebene der einzelnen Moleküle zu konzentrieren. Obwohl die Bildung des ersten selbstreplizierenden, höchstwahrscheinlich homochiralen Moleküls ein scheinbar unwahrscheinliches Ereignis ist, ist es bei näherer Betrachtung fast unvermeidlich, dass sich einige homochirale Moleküle einfach auf statistischer Basis gebildet haben. In diesem Fall wäre der nichtselektive Sprung zur Homochiralität einer der ersten Schritte der chemischen Evolution direkt aus einem racemischen "Ozean". Darüber hinaus konzentrieren sich die meisten Studien auf die Chiralität der ursprünglichen Monomere in Bezug auf ein asymmetrisches Kohlenstoffatom. Jedes Polymer mit einer Mindestgröße, die eine Faltung zu einer Sekundärstruktur erlaubt, würde jedoch spontan zu asymmetrischen höheren Strukturen (Konformationen) führen. Die meisten Funktionen dieser Polymere würden durch diese inhärent asymmetrische Faltung beeinflusst. Darüber hinaus wird ein Konzept der physikalischen Kompartimentierung auf der Basis von Gesteinsnanoporen in Analogie zu den Nanokavitäten digitaler Immunoassays vorgestellt, das darauf hindeutet, dass auch für die ersten Schritte der chemischen Evolution keine komplexen Zellwände oder Membranen notwendig waren. Zusammenfassend lässt sich sagen, dass einfache und universelle Mechanismen zu homochiralen selbstreplizierenden Systemen im Rahmen der chemischen Evolution geführt haben könnten. Ein homochiraler Monomerpool wird als unnötig angesehen, welcher auf der Urerde wahrscheinlich nie existiert hat. KW - Chemical evolution KW - Enantiomeric excess ee KW - Chirality KW - Racemate KW - Folding chirality KW - Self-assembly KW - self-replication KW - Single molecule KW - Prebiotic chemistry KW - Protein folding KW - Peptide folding KW - Proteinoid KW - Conformation KW - Segregation KW - Compartmentalization KW - Digital immunoassay KW - Porous rock KW - Miller and Urey KW - Primordial soup KW - Murchison meteorite KW - Micrometeorites KW - Tholins PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-598349 DO - https://doi.org/10.3390/life14030341 SN - 2075-1729 VL - 14 IS - 3 SP - 1 EP - 13 PB - MDPI CY - Basel AN - OPUS4-59834 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gugin, Nikita A1 - Yusenko, Kirill A1 - King, Andrew A1 - Meyer, Klas A1 - Al-Sabbagh, Dominik A1 - Villajos Collado, José Antonio A1 - Emmerling, Franziska T1 - Lighting up industrial mechanochemistry: Real-time in situ monitoring of reactive extrusion using energy-dispersive X-ray diffraction N2 - Mechanochemistry is an environmentally friendly synthetic approach that enables the sustainable production of a wide range of chemicals while reducing or eliminating the need for solvents. Reactive extrusion aims to move mechanochemistry from its conventional gram-scale batch reactions, typically performed in laboratory ball mills, to a continuous, large-scale process. Meeting this challenge requires in situ monitoring techniques to gain insights into reactive extrusion and its underlying processes. While the effectiveness of in situ Raman spectroscopy in providing molecular-level information has been demonstrated, our study uses energy-dispersive X-ray diffraction to monitor reactive extrusion in real time at the crystalline level. Our results provide previously unavailable control over the reactive extrusion process, promoting its perception as an industrially feasible green alternative to traditional solvent-based syntheses. KW - Mechanochemistry KW - Reactive extrusion KW - Green chemistry KW - In situ studies KW - Time-resolved in situ KW - TRIS KW - Synchrotron radiation KW - Scalable synthesis KW - Solid-state reactions KW - Reaction mechanisms PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-613969 DO - https://doi.org/10.1016/j.chempr.2024.07.033 VL - 10 IS - 11 SP - 1 EP - 16 PB - Elsevier B.V. AN - OPUS4-61396 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kader, A. A1 - Snellings, J. A1 - Adams, L. C. A1 - Gottheil, P. A1 - Mangarova, D. B. A1 - Heyl, J. L. A1 - Kaufmann, Jan Ole A1 - Moeckel, J. A1 - Brangsch, J. A1 - Auer, T. A. A1 - Collettini, F. A1 - Sauer, F. A1 - Hamm, B. A1 - Käs, J. A1 - Sack, I. A1 - Makowski, M. R. A1 - Braun, J. T1 - Sensitivity of magnetic resonance elastography to extracellular matrix and cell motility in human prostate cancer cell line-derived xenograft models N2 - Prostate cancer (PCa) is a significant health problem in the male population of the Western world. Magnetic resonance elastography (MRE), an emerging medical imaging technique sensitive to mechanical properties of biological tissues, detects PCa based on abnormally high stiffness and viscosity values. Yet, the origin of these changes in tissue properties and how they correlate with histopathological markers and tumor aggressiveness are largely unknown, hindering the use of tumor biomechanical properties for establishing a noninvasive PCa staging system. To infer the contributions of extracellular matrix (ECM) components and cell motility, we investigated fresh tissue specimens from two PCa xenograft mouse models, PC3 and LNCaP, using magnetic resonance elastography (MRE), diffusion-weighted imaging (DWI), quantitative histology, and nuclear shape analysis. Increased tumor stiffness and impaired water diffusion were observed to be associated with collagen and elastin accumulation and decreased cell motility. Overall, LNCaP, while more representative of clinical PCa than PC3, accumulated fewer ECM components, induced less restriction of water diffusion, and exhibited increased cell motility, resulting in overall softer and less viscous properties. Taken together, our results suggest that prostate tumor stiffness increases with ECM accumulation and cell adhesion - characteristics that influence critical biological processes of cancer development. MRE paired with DWI provides a powerful set of imaging markers that can potentially predict prostate tumor development from benign masses to aggressive malignancies in patients. Statement of significance: Xenograft models of human prostate tumor cell lines, allowing correlation of microstructure-sensitive biophysical imaging parameters with quantitative histological methods, can be investigated to identify hallmarks of cancer. KW - Magnetic resonance elastography KW - Quantitative histology KW - Prostate cancer KW - Stiffness KW - Fluidity KW - Apparent diffusion coefficient KW - Collagen KW - Elastin KW - Nuclear shape PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-618361 DO - https://doi.org/10.1016/j.bioadv.2024.213884 SN - 2772-9508 VL - 161 SP - 1 EP - 12 PB - Elsevier CY - Amsterdam AN - OPUS4-61836 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mangarova, Dilyana Branimirova A1 - Reimann, Carolin A1 - Kaufmann, Jan Ole A1 - Möckel, Jana A1 - Kader, Avan A1 - Adams, Lisa Christine A1 - Ludwig, Antje A1 - Onthank, David A1 - Robinson, Simon A1 - Karst, Uwe A1 - Helmer, Rebecca A1 - Botnar, Rene A1 - Hamm, Bernd A1 - Makowski, Marcus Richard A1 - Brangsch, Julia T1 - Elastin-specific MR probe for visualization and evaluation of an interleukin-1β targeted therapy for atherosclerosis N2 - Atherosclerosis is a chronic inflammatory condition of the arteries and represents the primary cause of various cardiovascular diseases. Despite ongoing progress, finding effective anti-inflammatory therapeutic strategies for atherosclerosis remains a challenge. Here, we assessed the potential of molecular magnetic resonance imaging (MRI) to visualize the effects of 01BSUR, an anti-interleukin-1β monoclonal antibody, for treating atherosclerosis in a murine model. Male apolipoprotein E-deficient mice were divided into a therapy group (01BSUR, 2 × 0.3 mg/kg subcutaneously, n = 10) and control group (no treatment, n = 10) and received a high-fat diet for eight weeks. The plaque burden was assessed using an elastin-targeted gadolinium-based contrast probe (0.2 mmol/kg intravenously) on a 3 T MRI scanner. T1-weighted imaging showed a significantly lower contrast-to-noise (CNR) ratio in the 01BSUR group (pre: 3.93042664; post: 8.4007067) compared to the control group (pre: 3.70679168; post: 13.2982156) following administration of the elastin-specific MRI probe (p < 0.05). Histological examinations demonstrated a significant reduction in plaque size (p < 0.05) and a significant decrease in plaque elastin content (p < 0.05) in the treatment group compared to control animals. This study demonstrated that 01BSUR hinders the progression of atherosclerosis in a mouse model. Using an elastin-targeted MRI probe, we could quantify these therapeutic effects in MRI. N2 - Atherosklerose ist eine chronische entzündliche Erkrankung der Arterien und die Hauptursache für verschiedene Herz-Kreislauf-Erkrankungen. Trotz kontinuierlicher Fortschritte ist es nach wie vor schwierig, wirksame entzündungshemmende Therapiestrategien für Atherosklerose zu finden. In dieser Studie haben wir das Potenzial der molekularen Magnetresonanztomographie (MRT) zur Visualisierung der Wirkung von 01BSUR, einem monoklonalen Anti-Interleukin-1β-Antikörper, zur Behandlung von Atherosklerose in einem Mausmodell untersucht. Männliche Apolipoprotein-E-defiziente Mäuse wurden in eine Therapiegruppe (01BSUR, 2 × 0,3 mg/kg subkutan, n = 10) und eine Kontrollgruppe (keine Behandlung, n = 10) aufgeteilt und erhielten acht Wochen lang eine fettreiche Diät. Die Plaquebelastung wurde mit einer auf Elastin ausgerichteten Kontrastmittelsonde auf Gadoliniumbasis (0,2 mmol/kg intravenös) auf einem 3-T-MRT-Scanner untersucht. Die T1-gewichtete Bildgebung zeigte ein signifikant niedrigeres Kontrast-Rausch-Verhältnis (CNR) in der 01BSUR-Gruppe (vorher: 3,93042664; nachher: 8,4007067) im Vergleich zur Kontrollgruppe (vorher: 3,70679168; nachher: 13,2982156) nach Verabreichung der Elastin-spezifischen MRT-Sonde (p < 0,05). Histologische Untersuchungen zeigten eine signifikante Verringerung der Plaque-Größe (p < 0,05) und eine signifikante Abnahme des Plaque-Elastin-Gehalts (p < 0,05) in der Behandlungsgruppe im Vergleich zu den Kontrolltieren. Diese Studie zeigte, dass 01BSUR das Fortschreiten der Atherosklerose in einem Mausmodell hemmt. Mit einer auf Elastin ausgerichteten MRT-Sonde konnten wir diese therapeutischen Effekte in der MRT quantifizieren. KW - Atherosclerosis KW - Molecular imaging KW - Elastin KW - Plaque KW - Interleukin-1beta PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-610858 DO - https://doi.org/10.1038/s41598-024-71716-5 VL - 14 IS - 1 SP - 1 EP - 11 PB - Springer Science and Business Media LLC AN - OPUS4-61085 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 - Fischer, Janina A1 - Kaufmann, Jan Ole A1 - Weller, Michael G. T1 - Simple Determination of Affinity Constants of Antibodies by Competitive Immunoassays N2 - The affinity constant, also known as the equilibrium constant, binding constant, equilibrium association constant, or the reciprocal value, the equilibrium dissociation constant (Kd), can be considered as one of the most important characteristics for any antibody–antigen pair. Many methods based on different technologies have been proposed and used to determine this value. However, since a very large number of publications and commercial datasheets do not include this information, significant obstacles in performing such measurements seem to exist. In other cases where such data are reported, the results have often proved to be unreliable. This situation may indicate that most of the technologies available today require a high level of expertise and effort that does not seem to be available in many laboratories. In this paper, we present a simple approach based on standard immunoassay technology that is easy and quick to perform. It relies on the effect that the molar IC50 approaches the Kd value in the case of infinitely small concentrations of the reagents. A two-dimensional dilution of the reagents leads to an asymptotic convergence to Kd. The approach has some similarity to the well-known checkerboard titration used for the optimization of immunoassays. A well-known antibody against the FLAG peptide, clone M2, was used as a model system and the results were compared with other methods. This approach could be used in any case where a competitive assay is available or can be developed. The determination of an affinity constant should belong to the crucial parameters in any quality control of antibody-related products and assays and should be mandatory in papers using immunochemical protocols. N2 - Die Affinitätskonstante, auch bekannt als Gleichgewichtskonstante, Bindungskonstante, Gleichgewichtsassoziationskonstante oder der reziproke Wert, die Gleichgewichtsdissoziationskonstante (Kd), kann als eine der wichtigsten Eigenschaften für jedes Antikörper-Antigen-Paar angesehen werden. Zur Bestimmung dieses Wertes wurden zahlreiche Methoden auf der Grundlage verschiedener Technologien vorgeschlagen und verwendet. Da jedoch eine sehr große Anzahl von Veröffentlichungen und kommerziellen Datenblätter diese Information nicht enthalten, scheint es erhebliche Hindernisse bei der Durchführung solcher Messungen zu geben. In anderen Fällen, in denen solche Daten angegeben werden, haben sich die Ergebnisse häufig als unzuverlässig erwiesen. Diese Situation könnte darauf hindeuten, dass die meisten der heute verfügbaren Technologien ein hohes Maß an Fachwissen und Aufwand erfordern, das in vielen Labors nicht vorhanden zu sein scheint. In diesem Beitrag stellen wir einen einfachen Ansatz vor, der auf der Standard-Immunoassay-Technologie basiert und einfach und schnell durchführbar ist. Er beruht auf dem Effekt, dass sich der molare IC50 bei unendlich kleinen Reagenz-Konzentrationen dem Kd-Wert annähert. Eine zweidimensionale Verdünnung der Reagenzien führt zu einer asymptotischen Konvergenz zu Kd. Der Ansatz hat eine gewisse Ähnlichkeit mit der bekannten Checkerboard-Titration, die zur Optimierung von Immunoassays verwendet wird. Ein bekannter Antikörper gegen das FLAG-Peptid, Klon M2, wurde als Modellsystem verwendet, und die Ergebnisse wurden mit anderen Methoden verglichen. Dieser Ansatz kann überall dort angewendet werden, wo ein kompetitiver Assay verfügbar ist oder entwickelt werden kann. Die Bestimmung einer Affinitätskonstante sollte zu den entscheidenden Parametern bei der Qualitätskontrolle von Antikörperprodukten und -assays gehören und in Arbeiten, die immunchemische Protokolle verwenden, obligatorisch sein. KW - ELISA KW - Competitive immunoassay KW - IC50 KW - Test midpoint KW - Point of inflection KW - Equilibrium constant KW - Dissociation constant KW - Binding strength KW - Antibody antigen complex KW - Bio-interaction KW - SPR KW - Surface-plasmon resonance KW - FLAG peptide KW - Clone M2 KW - Antibody quality PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-605607 DO - https://doi.org/10.3390/mps7030049 SN - 2409-9279 VL - 7 IS - 3 SP - 1 EP - 11 PB - MDPI CY - Basel AN - OPUS4-60560 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Raysyan, Anna A1 - Zwigart, S. A1 - Eremin, S. A. A1 - Schneider, Rudolf T1 - BPA Endocrine Disruptor Detection at the Cutting Edge: FPIA and ELISA Immunoassays N2 - BPA is a chemical commonly used in the production of polymer-based materials that can have detrimental effects on the thyroid gland and impact human reproductive health. Various expensive methods, such as liquid and gas chromatography, have been suggested for detecting BPA. The fluorescence polarization immunoassay (FPIA) is an inexpensive and efficient homogeneous mix-and-read method that allows for high-throughput screening. FPIA offers high specificity and sensitivity and can be carried out in a single phase within a timeframe of 20–30 min. In this study, new tracer molecules were designed that linked the fluorescein fluorophore with and without a spacer to the bisphenol A moiety. To assess the influence of the C6 spacer on the sensitivity of an assay based on the respective antibody, hapten–protein conjugates were synthesized and assessed for performance in an ELISA setup, and this resulted in a highly sensitive assay with a detection limit of 0.05 µg/L. The lowest limit of detection was reached by employing the spacer derivate in the FPIA and was 1.0 µg/L, working range from 2 to 155 µg/L. The validation of the methods was conducted using actual samples compared to LC–MS/MS, which served as the reference method. The FPIA and ELISA both demonstrated satisfactory concordance. KW - Fluorescence Polarization KW - Enzyme-Linked Immunosorbent Assay KW - Endokriner Disruptor KW - Bisphenol A KW - Freisetzung PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-579497 DO - https://doi.org/10.3390/bios13060664 VL - 13 IS - 6 SP - 1 EP - 12 PB - MDPI CY - Basel AN - OPUS4-57949 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stratulat, C. A1 - Ginghina, R. E. A1 - Bratu, A. E. A1 - Isleyen, A. A1 - Tunc, M. A1 - Hafner-Vuk, K. A1 - Frey, A. M. A1 - Kjeldsen, H. A1 - Vogl, Jochen T1 - Development- and Validation-Improved Metrological Methods for the Determination of Inorganic Impurities and Ash Content from Biofuels N2 - In this study, five laboratories, namely, BRML (Romania), TUBITAK UME (Turkey), IMBIH (Bosnia and Herzegovina), BAM (Germany), and DTI (Denmark), developed and validated analytical procedures by ICP-MS, ICP-OES, MWP-AES, WD-XRF, and ID-MS for the determination of inorganic impurities in solid and liquid biofuels, established the budget of uncertainties, and developed the method for determining the amount of ash in the measurement range 0–1.2% with absolute repeatability less than 0.1% and absolute reproducibility of 0.2% (according to EN ISO 18122). In order to create homogeneous certified reference materials, improved methodologies for the measurement and characterization of solid and liquid biofuels were developed. Thus, information regarding the precision, accuracy, and bias of the method, and identifying the factors that intervened in the measurement of uncertainty were experimentally determined, supplementing the information from the existing standards in the field. KW - Development KW - Validate method KW - Biodiesel KW - ICP-MS KW - ICP-OES KW - MW-AES KW - WD-XRF KW - ID-MS KW - Inorganic impurities KW - Ash content KW - Wood chips PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-578743 DO - https://doi.org/10.3390/en16135221 VL - 16 IS - 13 SP - 1 EP - 14 PB - MDPI AN - OPUS4-57874 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - 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 - 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 - Kazlagić, Anera A1 - Rosner, M. A1 - Cipriani, A. A1 - Frick, D. A. A1 - Glodny, J. A1 - Hoffmann, E. J. A1 - Hora, J. M. A1 - Irrgeher, J. A1 - Lugli, F. A1 - Magna, T. A1 - Meisel, T. C. A1 - Meixner, A. A1 - Possolo, A. A1 - Pramann, A. A1 - Pribil, M. J. A1 - Prohaska, T. A1 - Retzmann, Anika A1 - Rienitz, O. A1 - Rutherford, D. A1 - Paula-Santos, G. M. A1 - Tatzel, M. A1 - Widhalm, S. A1 - Willbold, M. A1 - Zuliani, T. A1 - Vogl, Jochen T1 - Characterisation of conventional 87Sr/86Sr isotope ratios in cement, limestone and slate reference materials based on an interlaboratory comparison study N2 - An interlaboratory comparison (ILC)was organised to characterise 87Sr/86Sr isotope ratios in geological and industrial reference materials by applying the so-called conventional method for determining 87Sr/86Sr isotope ratios. Four cements (VDZ 100a,VDZ 200a, VDZ 300a, IAG OPC-1), one limestone (IAG CGL ML-3) and one slate (IAG OU-6) reference materials were selected, covering a wide range of naturally occurring Sr isotopic signatures. Thirteen laboratories received aliquots of these six reference materials together with a detailed technical protocol. The consensus values for the six reference materials and their associated measurement uncertainties were obtained by applying a Gaussian, linear mixed effects model fitted to all the measurement results. By combining the consensus values and their uncertainties with an uncertainty contribution for potential heterogeneity, reference values ranging from 0.708134 mol mol-1 to 0.729778 mol mol-1 were obtained with relative expanded uncertainties of ≤ 0.007 %. This study represents an ILC on conventional 87Sr/86Sr isotope ratios, within which metrological principles were considered and the compatibility of measurement results obtained by MC-ICP-MS and by MC-TIMS is demonstrated. The materials characterised in this study can be used as reference materials for validation and quality control purposes and to estimate measurement uncertainties in conventional 87Sr/86Sr isotope ratio measurement. KW - Sr isotope analysis KW - Isotope ratios KW - Cement KW - Geological material KW - MC-TIMS KW - MC-ICP-MS KW - Interlaboratory comparison KW - Measurement uncertainty KW - Cconventional method PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-579836 DO - https://doi.org/10.1111/ggr.12517 SN - 1639-4488 VL - 47 IS - 4 SP - 821 EP - 840 PB - Wiley online library AN - OPUS4-57983 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 - Hendriks, L. A1 - Brunjes, R. A1 - Taskula, S. A1 - Kocic, J. A1 - Hattendorf, B. A1 - Bland, G. A1 - Lowry, G. A1 - Bolea-Fernandez, E. A1 - Vanhaecke, F. A1 - Wang, J. A1 - Baalousha, M. A1 - von der Au, Marcus A1 - Meermann, Björn A1 - Holbrook, T. A1 - Wagner, S. A1 - Harycki, S. A1 - Gundlach-Graham, A. A1 - von der Kammer, F. T1 - Results of an interlaboratory comparison for characterization of Pt nanoparticles using single-particle ICP-TOFMS N2 - This study describes an interlaboratory comparison (ILC) among nine (9) laboratories to evaluate and validate the standard operation procedure (SOP) for single-particle (sp) ICP-TOFMS developed within the context of the Horizon 2020 project ACEnano. The ILC was based on the characterization of two different Pt nanoparticle (NP) suspensions in terms of particle mass, particle number concentration, and isotopic composition. The two Pt NP suspensions were measured using icpTOF instruments (TOFWERK AG, Switzerland). Two Pt NP samples were characterized and mass equivalent spherical sizes (MESSs) of 40.4 ± 7 nm and 58.8 ± 8 nm were obtained, respectively. MESSs showed <16% relative standard deviation (RSD) among all participating labs and <4% RSD after exclusion of the two outliers. A good agreement was achieved between the different participating laboratories regarding particle mass, but the particle number concentration results were more scattered, with <53% RSD among all laboratories, which is consistent with results from previous ILC studies conducted using ICP-MS instrumentation equipped with a sequential mass spectrometer. Additionally, the capabilities of sp-ICP-TOFMS to determine masses on a particle basis are discussed with respect to the potential for particle density determination. Finally, because quasi-simultaneous multi-isotope and multielement determinations are a strength of ICP-TOFMS instrumentation, the precision and trueness of isotope ratio determinations were assessed. The average of 1000 measured particles yielded a precision of below ±1% for intensity ratios of the most abundant Pt isotopes, i.e. 194Pt and 195Pt, while the accuracy of isotope ratios with the lower abundant isotopes was limited by counting statistics. KW - ILC KW - spICP-MS KW - PtNP KW - Nanopartikel PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-580353 DO - https://doi.org/10.1039/d3nr00435j SN - 2040-3364 VL - 15 IS - 26 SP - 11268 EP - 11279 PB - Royal Society of Chemistry (RSC) AN - OPUS4-58035 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Retzmann, Anika A1 - Faßbender, Sebastian A1 - Rosner, M. A1 - von der Au, Marcus A1 - Vogl, Jochen T1 - Performance of second generation ICP-TOFMS for (multi-)isotope ratio analysis: a case study on B, Sr and Pb and their isotope fractionation behavior during the measurements N2 - The performance of second generation ICP-TOFMS, equipped with a micro-channel plate (MCP) enabling multi-isotope detection, in terms of isotope ratio precision and instrumental isotopic fractionation (IIF) for (multi-)isotope ratio analysis was thoroughly assessed for B, Sr and Pb. Experimental isotope ratio precision of 0.14 % for 11B/10B intensity ratio, 0.15 % for 87Sr/86Sr intensity ratio and 0.07% for 208Pb/206Pb intensity ratio were obtained at high signal levels ($500 mg L−1) which is comparable to first generation ICP-TOFMS. The long-term stability of isotope ratios, measured over several hours and expressed as repeatability, is between 0.05 % and 1.8 % for B, Sr and Pb. The observed IIF per mass unit is negative for B (i.e., −11 % for 11B/10B) which is in accordance with measurements using sector field (MC) ICP-MS. But the observed IIF per mass unit is positive for Sr (i.e., 2 % for 87Sr/86Sr) and Pb (i.e., 4.5 % for 208Pb/206Pb) which is not in accordance with measurements using sector field (MC) ICP-MS. Furthermore, different IIFs per mass unit were observed for different isotope pairs of the same isotopic system (i.e., Sr, Pb) and adjacent isotopic systems (i.e., Pb vs. Tl). This and the observations from three-isotope plots for Sr and Pb show that ion formation, ion extraction, ion transmission, ion separation and ion detection in second generation ICP-TOFMS is subject to IIF that does not follow the known mass dependent fractionation laws and is possibly caused by mass independent fractionation and/or multiple (contradictory) fractionation processes with varying contributions. The non-mass dependent IIF behavior observed for second generation ICP TOFMS has profound consequences for the IIF correction of isotope raw data, including application of multi-isotope dilution mass spectrometry (IDMS) using ICP-TOFMS. Hence, only IIF correction models that correct also for mass independent fractionation are applicable to calculate reliable isotope ratios using second generation ICP-TOFMS. In the present study, reliable d11B values, and absolute B, Sr and Pb isotope ratios could be determined using the SSB approach in single-element solutions as well as in a mixture of B, Sr and Pb, where the isotopes were measured simultaneously. KW - ICP-TOFMS KW - Isotope delta value KW - Isotope amount ratio KW - Conventional isotope ratio KW - Instrumental isotope fractionation PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-582239 DO - https://doi.org/10.1039/d3ja00084b SN - 0267-9477 VL - 38 IS - 10 SP - 2144 EP - 2158 PB - Royal Society of Chemistry AN - OPUS4-58223 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gehrenkemper, Lennart A1 - Rühl, Isabel A1 - Westphalen, Tanja A1 - Simon, Fabian A1 - von der Au, Marcus A1 - Cossmer, Antje A1 - Meermann, Björn T1 - Investigating the uptake and fate of per- and polyfluoroalkylated substances (PFAS) in bean plants (Phaseolus vulgaris): comparison between target MS and sum parameter analysis via HR-CS-GFMAS N2 - AbstractIn this study, we present a screening method based on molecular absorption spectrometry to study PFAS uptake and fate in plants. To evaluate the suitability of this method we analyzed plant extracts with molecular absorption spectrometry (MAS) as well as liquid chromatography–tandem mass spectrometry (LC–MS/MS) for mass balance studies (w(F)). French bean plants (Phaseolus vulgaris) were grown on soil spiked using eight PFAS substances that vary in chain length and functional group composition. Specifically, these include three short-chained (C4–C5), five long-chained (C7–C10) carboxylic acids, one sulfonic acid and one sulfonic amide moieties. To investigate substance-specific PFAS uptake systematically, PFAS were spiked as single substance spike. Additionally, we studied one mixture of the investigated substances in equal proportions regarding w(F) and four PFAS mixtures of unknown composition. After 6 weeks, the plants were separated into four compartments. We analyzed the four compartments as well as the soil for extractable organically bound fluorine (EOF) by high resolution-continuum source-graphite furnace-molecular absorption spectrometry (HR-CS-GFMAS) as well as for sum of ten target-PFAS by LC–MS/MS. All three short-chained PFAS perfluorobutanoic acid (PFBA), perfluorobutanoic sulfonic acid (PFBS) and perfluoropentanoic acid (PFPeA) were determined in high concentrations mainly in the fruits of the investigated plants while long-chained PFAS perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA) were mainly determined in roots. PFBS was determined in remarkably high concentrations in leaves compartment by both quantification methods. Overall, comprehensive results of single substance spikes were in good agreement for both methods except for a few cases. Hence, two phenomena were identified: for mixed PFAS spikes of unknown composition huge differences between EOF and sum of target PFAS were observed with systematically higher EOF values. Overall, both methods indicate comparable results with MS being more reliable for known PFAS contamination and MAS being more valuable to identify PFAS exposure of unknown composition. Graphical Abstract KW - Pollution PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-589394 DO - https://doi.org/10.1186/s12302-023-00811-7 VL - 35 IS - 104 SP - 1 EP - 13 PB - Springer Science and Business Media LLC AN - OPUS4-58939 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rieger, Philip A1 - Magnall, Joseph M. A1 - Gleeson, Sarah A. A1 - Oelze, Marcus T1 - Pyrite chemistry records a multistage ore forming system at the Proterozoic George Fisher massive sulfide Zn-Pb-Ag deposit, Mount Isa, Australia N2 - Trace element (TE) analysis of pyrite via LA-ICP-MS can be used to reconstruct the conditions of pyrite formation in complex mineral systems. The Carpentaria province in northern Australia is host to some of the world’s highest value Zn-Pb (+Ag, Cu) deposits. The genesis of many of these deposits is controversial, with competing models of single-vs. multi-stage ore formation. In this study, LA-ICP-MS data of paragenetically constrained pyrite from the George Fisher Zn-Pb-Ag deposit has been analysed to investigate the chemistry of different stages of ore formation. Pyrite from correlative unmineralized host rocks has also been analysed to investigate evidence of distal hydrothermal anomalism. All LA-ICP-MS data have been statistically evaluated (principal component analysis) and interpreted together with whole rock lithogeochemical data of the same samples. Pre-ore diagenetic pyrite is compositionally similar to other Proterozoic diagenetic pyrite, with some evidence of minor hydrothermal anomalism that with further analysis could help define distal alteration. Pyrite from the different ore stages are compositionally distinct, consistent with a multi-stage system. Ore stage 1 pyrite exceeds background contents of Co, Cu, Zn, As, Ag, Sb, Tl, and Pb and has elevated Co/Ni ratios, whereas only Ni and Co are above background abundances in ore stage 2 and 3 pyrite, of which only ore stage 3 pyrite has high Co/Ni ratios. Ore stage 1 pyrite has a similar composition to hydrothermal pyrite in the undeformed northern Carpentaria CD-type deposits and was likely syn-diagenesis. Ore stage 2 was syn-deformation, and resulted in replacement and recrystallization of pre-existing pyrite, and the expulsion of incompatible TEs. Ore stage 3 formed via a later Cu-Zn-Pb mineralizing event that resulted in a new geochemically distinct generation of Co-rich pyrite. Overall, this study demonstrates the value of paragenetically-constrained pyrite TE data for refining genetic models in complex sediment hosted mineral systems. KW - General Earth and Planetary Sciences PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-590407 DO - https://doi.org/10.3389/feart.2023.892759 VL - 11 SP - 1 EP - 19 PB - Frontiers Media SA AN - OPUS4-59040 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Inostroza, Manuel A1 - Fernandez, Bárbara A1 - Aguilera, Felipe A1 - Layana, Susana A1 - Walter, Thomas R. A1 - Zimmer, Martin A1 - Rodríguez-Díaz, Augusto A1 - Oelze, Marcus T1 - Physical and chemical characteristics of active sulfur flows observed at Lastarria volcano (northern Chile) in January 2019 N2 - Molten sulfur is found in various subaerial volcanoes. However, limited records of the pools and flows of molten sulfur have been reported: therefore, questions remain regarding the physicochemical processes behind this phenomenon. A suite of new sulfur flows, some of which active, was identified at the Lastarria volcano (northern Chile) and studied using satellite imagery, in situ probing, and temperature and video recording. This finding provides a unique opportunity to better understand the emplacement mechanisms and mineral and chemical compositions of molten sulfur, in addition to gaining insight into its origin. Molten sulfur presented temperatures of 124–158°C, with the most prolonged sulfur flow reaching 12 m from the source. Photogrammetric tools permitted the identification of levees and channel structures, with an estimated average flow speed of 0.069 m/s. Field measurements yielded a total volume of 1.45 ± 0.29 m3 of sulfur (equivalent to ∼2.07 tons) mobilized during the January 2019 event for at least 408 min. Solidified sulfur was composed of native sulfur with minor galena and arsenic- and iodine-bearing minerals. Trace element analysis indicated substantial enrichment of Bi, Sb, Sn, Cd, as well as a very high concentration of As (&gt;40.000 ppm). The January 2019 molten sulfur manifestations in Lastarria appear to be more enriched in As compared to the worldwide known volcanoes with molten sulfur records, such as the Shiretoko-Iozan and Poás volcanoes. Furthermore, their rheological properties suggest that the “time of activity” in events such as this could be underestimated as flows in Lastarria have moved significantly slower than previously thought. The origin of molten sulfur is ascribed to the favorable S-rich chemistry of fumarolic gases and changes in host rock permeability (fracture opening). Molten sulfur in Lastarria correlates with a peak in activity characterized by high emissions of SO2 and other acid species, such as HF and HCl, in addition to ground deformation. Consequently, molten sulfur was framed within a period of volcanic unrest in Lastarria, triggered by changes in the magmatic-hydrothermal system. The appearance of molten sulfur is related to physicochemical perturbations inside the volcanic system and is perhaps a precursor of eruptive activity, as observed in the Poás and Turrialba volcanoes. KW - General Earth and Planetary Sciences PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-590331 DO - https://doi.org/10.3389/feart.2023.1197363 VL - 11 SP - 1 EP - 18 PB - Frontiers Media SA AN - OPUS4-59033 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Völker, Tobias A1 - Gornushkin, Igor B. T1 - Investigation of a method for the correction of self-absorption by Planck function in laser induced breakdown spectroscopy N2 - The electron density and temperature of a laser-induced plasma can be determined from the width and intensity of the spectral lines, provided that the corresponding optical transitions are optically thin. However, the lines in laser induced plasma are often self-absorbed. One of the methods of correction of this effect is based on the use of the Planck function and an iterative numerical calculation of the plasma temperature. In this study, the method is further explored and its inherent errors and limitations are evaluated. For this, synthetic spectra are used that fully correspond to the assumed conditions of a homogeneous isothermal plasma at local thermodynamic equilibrium. Based on the error analysis, the advantages and disadvantages of the method are discussed in comparison with other methods of self-absorption correction. KW - LIBS KW - Self-absorption KW - Planck function PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-572677 DO - https://doi.org/10.1039/D2JA00352J SN - 0267-9477 SP - 1 EP - 6 PB - Royal Society of Chemistry (RSC) AN - OPUS4-57267 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Riedel, Soraya A1 - Jaut, Valerie A1 - Schneider, Rudolf T1 - Ergometrine sensing in rye flour by a magnetic bead-based immunoassay followed by flow injection analysis with amperometric detection N2 - A certain group of mycotoxins, the ergot alkaloids, has caused countless deaths throughout human history. They are found in rye and other cereals and ingesting contaminated foods can cause serious health problems. To identify contaminated food exceeding the legal limits for ergot alkaloids, a portable and cost-effective test system is of great interest to the food industry. Rapid analysis can be achieved by screening for a marker compound, for which we chose ergometrine. We developed a magnetic bead-based immunoassay for ergometrine with amperometric detection in a flow injection system using a handheld potentiostat and a smartphone. With this assay a limit of detection of 3 nM (1 μg/L) was achieved. In spiked rye flour, ergometrine levels from 25 to 250 μg/kg could be quantified. All results could be verified by optical detection. The developed assay offers great promise to meet the demand for on-site ergometrine detection in the food industry. KW - Ergot alkaloids KW - Amperometry KW - Magnetic beads KW - Immunoassay KW - Food analysis KW - Fow injection analysis KW - Mycotoxins PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-565906 DO - https://doi.org/10.1016/j.talanta.2022.124172 SN - 0039-9140 N1 - Geburtsname von Riedel, Soraya: Höfs, S. - Birth name of Riedel, Soraya: Höfs, S. VL - 254 IS - 124172 SP - 1 EP - 8 PB - Elsevier B.V. AN - OPUS4-56590 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Westwood, Steven A1 - Lippa, Katrice A1 - Shimuzu, Yoshitaka A1 - Lalerle, Beatrice A1 - Saito, Takeshi A1 - Duewer, David A1 - Dai, Xinhua A1 - Davies, Stephen A1 - Ricci, Marina A1 - Baldan, Annarita A1 - Lang, Brian A1 - Sarge, Stefan A1 - Wang, Haifeng A1 - Pratt, Ken A1 - Josephs, Ralf A1 - Mariassy, Mikael A1 - Pfeifer, Dietmar A1 - Warren, John A1 - Bremser, Wolfram A1 - Ellison, Stephen A1 - Toman, Blaza A1 - Nelson, Michael A1 - Huang, Ting A1 - Fajgelj, Ales A1 - Gören, Ahmet A1 - Mackay, Lindsey A1 - Wielgosz, Robert T1 - Methods for the SI-traceable value assignment of the purity of organic compounds (IUPAC Technical Report) N2 - The “purity” of an organic compound typically refers, in practice, to an assignment of the mass fraction content of the primary organic component present in the material. The “purity” value of an organic primary calibrator material is the ultimate source of metrological traceability of any quantitative measurement of the content of that compound in a given matrix. The primary calibrator may consist of a Certified Reference Material (CRM) whose purity has been assigned by the CRM producer or a laboratory may choose to value-assign a material to the extent necessary for their intended application by using appropriately valid methods. This report provides an overview of the approach, performance and applicability of the principal methods used to determine organic purity including mass balance, quantitative NMR, thermal methods and direct-assay techniques. A statistical section reviews best practice for combination of data, value assignment as the upper limit values corresponding to 100 % purity are approached and how to report and propagate the standard uncertainty associated with the assigned values. KW - Calibration hierarchy KW - Certified reference materials KW - Mass balance KW - Measurement uncertainty KW - Organic purity KW - Primary calibrators KW - Primary reference materials KW - qNMR KW - Related-structure impurities KW - Thermal analysis KW - Titrimetry KW - Traceability KW - Uncertainty propagation KW - Volatile organic compounds KW - Water content PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-627932 DO - https://doi.org/10.1515/pac-2020-0804 SN - 0033-4545 SN - 1365-3075 VL - 95 IS - 1 SP - 1 EP - 77 PB - de Gruyter CY - Berlin AN - OPUS4-62793 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fiedler, Saskia A1 - Ton-That, C. A1 - Phillips, M. R. T1 - Defect-free ZnO nanorods with high angular distribution for enhanced excitonic emission N2 - AbstractLow-temperature hydrothermal growth has emerged as a popular method for the fabrication of ZnO nanorods (NRs), increasing the functionality and utility of ZnO-based devices. In this work, we study the influence of growth time, temperature and seed layer on the dimensions and angular distribution of ZnO NRs. High-quality NRs with a crisscrossed 60° angular distribution have been grown with a 20–60 nm diameter and 600 nm length. We show that, within the ideal range of growth parameters, the growth time and temperature have no controllable influence on NR diameter and length, while the deposition method and size of the pre-growth deposited ZnO seeds affects diameter and NR angular alignment. We demonstrate advantages of using crisscross-aligned NRs over planar ZnO for the enhancement of ZnO excitonic emission by optical coupling with gold nanoparticles. These results can be readily adapted for applications that involve surface coating-mediated enhancement of both light emission and injection. KW - ZnO nanorod KW - Hydrothermal growth KW - Seed layer KW - Angular distribution KW - Cathodoluminescence KW - Luminescence enhancement PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-618176 DO - https://doi.org/10.1557/s43578-023-00941-x SN - 0884-2914 SN - 2044-5326 VL - 38 IS - 8 SP - 2145 EP - 2155 PB - Springer CY - Berlin AN - OPUS4-61817 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ecke, Alexander A1 - Bell, Jérémy A1 - Schneider, Rudolf T1 - A three-dimensional microfluidic flow cell and system integration for improved electrochemical substrate detection in HRP/TMB-based immunoassays N2 - Immunoassays, based on the recognition and capture of analytes by highly selective antibodies, are now used extensively in all areas of diagnostics, but the challenge is to further integrate them into online sensors. To improve the transition from laboratory immunoassays to immunosensors, we have developed a complete flow system, based on a microfluidic core flow cell to enable automated detection of one of the most commonly used immunoassay substrates, TMB, by chronoamperometry. The architecture and fluidic optimisation of the system showed that a specially designed 3D flow cell allows higher flow rates (500 μL min−1) than a standard enlarged microfluidic channel (50 μL min−1) resulting in a significantly shorter detection time of 30 seconds per sample and making the system more robust against interferences due to bubble formation in the chip. The electrochemical measurements showed an improved signal-to-noise ratio (SNR) and thus higher sensitivity for a model immunoassay for diclofenac (SNR = 59), compared to the analytical performance of a conventional laboratory microplate-based assay with optical detection (SNR = 19). In general, this system facilitates the conversion of any conventional immunoassay into an immunosensor with automatic and continuous detection. KW - Microfluidic KW - Immunoassay KW - Electrochemical KW - Mikrofluidik KW - Immunassay KW - Elektrochemie PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-580159 DO - https://doi.org/10.1039/d3sd00095h VL - 2 SP - 887 EP - 892 PB - Royal Society of Chemistry CY - London, United Kingdom AN - OPUS4-58015 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Roesch, Philipp A1 - Vogel, Christian A1 - Wittwer, Philipp A1 - Huthwelker, T. A1 - Borca, C. A1 - Sommerfeld, Thomas A1 - Kluge, Stephanie A1 - Piechotta, Christian A1 - Kalbe, Ute A1 - Simon, Franz-Georg T1 - Taking a Look at the Surface: µ-XRF Mapping and Fluorine K-edge µ-XANES Spectroscopy of Organofluorinated Compounds in Environmental Samples and Consumer Products N2 - For the first time, µ-X-ray fluorescence (µ-XRF) mapping combined with fluorine K-edge µ-X-ray absorption near-edge structure (µ-XANES) spectroscopy was applied to depict per- and polyfluoroalkyl substances (PFAS) contamination and inorganic fluoride in samples concentrations down to 100 µg/kg fluoride. To demonstrate the matrix tolerance of the method, several PFAS contaminated soil and sludge samples as well as selected consumer product samples (textiles, food contact paper and permanent baking sheet) were investigated. µ-XRF mapping allows for a unique element-specific visualisation at the sample surface and enables localisation of fluorine containing compounds to a depth of 1 µm. Manually selected fluorine rich spots were subsequently analysed via fluorine K-edge µ-XANES spectroscopy. To support spectral interpretation with respect to inorganic and organic chemical distribution and compound class determination, linear combination (LC) fitting was applied to all recorded µ-XANES spectra. Complementarily, solvent extracts of all samples were target-analysed via LC-MS/MS spectrometry. The detected PFAS sum values range from 20 to 1136 µg/kg dry weight (dw). All environmentally exposed samples revealed higher concentration of PFAS with a chain length >C8 (e.g. 580 µg/kg dw PFOS for Soil1), whereas the consumer product samples showed a more uniform distribution with regard to chain lengths from C4 to C8. Independent from quantified PFAS amounts via target analysis, µ-XRF mapping combined with µ-XANES spectroscopy was successfully applied to detect both point-specific concentration maxima and evenly distributed surface coatings of fluorinated organic contaminants in the corresponding samples. KW - PFAS KW - XRF KW - LC-MS/MS KW - XANES KW - Fluoride KW - Soil PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-576109 DO - https://doi.org/10.1039/D3EM00107E SN - 2050-7887 SP - 1 EP - 12 PB - Royal Society of Chemistry AN - OPUS4-57610 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kowalewska, Z. A1 - Abad Andrade, Carlos Enrique A1 - Okruss, M. A1 - Recknagel, Sebastian T1 - Feasibility of high-resolution continuum source molecular absorption spectrometry for vanadium determination N2 - This work aimed to evaluate high-resolution continuum source molecular absorption spectrometry (HR-CS MAS), traditionally used to determine non-metals, for the determination of a new element, metal, vanadium. VO was selected as a target molecule because it is relatively stable and was expected to be spontaneously generated in a flame or a graphite furnace (GF). The high-resolution overview spectra of the molecule were obtained in a wide range of 480–630 nm, and absorption due to the X4Σ−–C4Σ− electronic transition was registered. A unique instrumental setup, comprising a prototype Modular Simultaneous Echelle Spectrograph (MOSES) and a commercial HR-CS MAS apparatus, was applied in the research. Finally, the spectral area centered at 550.6230 nm was selected for analysis. A method was developed to determine V in solutions of catalysts of heavy petroleum oil hydroprocessing using a commercial HR-CS spectrometer in a flame version. Although sensitivity was relatively poor (characteristic concentration 380 mg L−1), an extremely low noise enabled reaching a satisfactory detection limit (20 mg L−1 in solution, i.e. 0.1% m:m in the catalyst). For the first time vanadium was determined using ordinary air-acetylene flame. The obtained results were consistent with the results of atomic absorption spectrometry with N2O-C2H2 flame. Unfortunately, only a small population of VO molecules could have been generated in GF measurements. Furthermore, the observed VO molecules appeared only at unfavorably high temperatures. The work shows the potential of HR-CS MAS as a scientific tool for investigating the mechanism of processes occurring in the GF. This work can inspire other research of new analytes for HR-CS MAS. KW - Vanadium KW - HR-CS-MAS KW - VO KW - High-resolution continuum source molecular absorption spectrometry KW - AAS PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-569899 DO - https://doi.org/10.1039/D2JA00281G SN - 0267-9477 VL - 38 IS - 2 SP - 472 EP - 483 PB - Royal Society of Chemistry AN - OPUS4-56989 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sowoidnich, K. A1 - Maiwald, M. A1 - Ostermann, Markus A1 - Sumpf, B. T1 - Shifted excitation Raman difference spectroscopy for soil component identification and soil carbonate determination in the presence of strong fluorescence interference N2 - Detailed knowledge about soil composition is an important prerequisite for many applications, for example precision agriculture. Current standard laboratory methods are complex and time-consuming but could be complemented by non-invasive optical techniques. Its capability to provide a molecular fingerprint of individual soil components makes Raman spectroscopy a very promising candidate. A major challenge is strong fluorescence interference inherent to soil, but this issue can be overcome effectively using shifted excitation Raman difference spectroscopy (SERDS). A customized dual-wavelength diode laser emitting at 785.2 and 784.6 nm was used to investigate 117 soil samples collected from an agricultural field along a distance of 624 m and down to depths of 1 m. To address soil spatial heterogeneity, a raster scan approach comprising 100 measurement spots per sample was applied. Based on the Raman spectroscopic fingerprint extracted from intense fluorescence interference by SERDS, 13 mineral soil constituents were identified, and even closely related molecular species could be discriminated, for example polymorphs of titanium dioxide and calcium carbonate. For the first time, the capability of SERDS is demonstrated to predict the calcium carbonate content as an important soil parameter using partial least squares regression (R2 = 0.94, root mean square error of cross-validation RMSECV = 2.1%). Our findings demonstrate that SERDS can extract a wealth of spectroscopic information from disturbing backgrounds enabling qualitative and quantitative soil analysis. This highlights the large potential of SERDS for precision agriculture but also in further application areas, for example geology, cultural heritage and planetary exploration. KW - Calcium carbonate KW - Raman spectroscopy KW - Soil KW - X-Ray fluorescence KW - SERDS PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-569016 DO - https://doi.org/10.1002/jrs.6500 SN - 0377-0486 IS - Special Issue SP - 1 EP - 14 PB - John Wiley & Sons Ltd. CY - Hoboken, New Jersey, USA AN - OPUS4-56901 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 - Lozano-Martín, D. A1 - Tuma, Dirk A1 - Kipphardt, Heinrich A1 - Khanipour, Peyman A1 - Chamorro, C. R. T1 - Thermodynamic characterization of the (H2 + C3H8) system significant for the hydrogen economy: Experimental (p, rho, T) determination and equation-of-state modelling N2 - For the gradual introduction of hydrogen in the energy market, the study of the properties of mixtures of hydrogen with typical components of natural gas (NG) and liquefied petroleum gas (LPG) is of great importance. This work aims to provide accurate experimental (p, rho, T) data for three hydrogen-propane mixtures with nominal compositions (amount of substance, mol/mol) of (0.95 H2 + 0.05 C3H8), (0.90 H2 + 0.10 C3H8), and (0.83 H2 + 0.17 C3H8), at temperatures of 250, 275, 300, 325, 350, and 375 K, and pressures up to 20 MPa. A single-sinker densimeter was used to determine the density of the mixtures. Experimental density data were compared to the densities calculated from two reference equations of state: the GERG-2008 and the AGA8-DC92. Relative deviations from the GERG-2008 EoS are systematically larger than those from the AGA8-DC92. They are within the ±0.5% band for the mixture with 5% of propane, but deviations are higher than 0.5% for the mixtures with 10% and 17% of propane, especially at low temperatures and high pressures. Finally, the sets of new experimental data have been processed by the application of two different statistical equations of state: the virial equation of state, through the second and third virial coefficients, B(T, x) and C(T, x), and the PC-SAFT equation of state. KW - Hydrogen-containing gas mixture KW - Density data KW - Equation of state KW - Virial coefficients PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-570056 DO - https://doi.org/10.1016/j.ijhydene.2022.11.170 SN - 0360-3199 VL - 48 IS - 23 SP - 8645 EP - 8667 PB - Elsevier B. V. CY - Amsterdam AN - OPUS4-57005 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Erler, A. A1 - Riebe, D. A1 - Beitz, T. A1 - Löhmannsröben, H.-G. A1 - Leenen, M. A1 - Pätzold, S. A1 - Ostermann, Markus A1 - Wójcik, M. T1 - Mobile Laser-Induced Breakdown Spectroscopy for Future Application in Precision Agriculture—A Case Study N2 - In precision agriculture, the estimation of soil parameters via sensors and the creation of nutrient maps are a prerequisite for farmers to take targeted measures such as spatially resolved fertilization. In this work, 68 soil samples uniformly distributed over a field near Bonn are investigated using laser-induced breakdown spectroscopy (LIBS). These investigations include the determination of the total contents of macro- and micronutrients as well as further soil parameters such as soil pH, soil organic matter (SOM) content, and soil texture. The applied LIBS instruments are a handheld and a platform spectrometer, which potentially allows for the single-point measurement and scanning of whole fields, respectively. Their results are compared with a high-resolution lab spectrometer. The prediction of soil parameters was based on multivariate methods. Different feature selection methods and regression methods like PLS, PCR, SVM, Lasso, and Gaussian processes were tested and compared. While good predictions were obtained for Ca, Mg, P, Mn, Cu, and silt content, excellent predictions were obtained for K, Fe, and clay content. The comparison of the three different spectrometers showed that although the lab spectrometer gives the best results, measurements with both field spectrometers also yield good results. This allows for a method transfer to the in-field measurements KW - LIBS KW - Precision agriculture KW - Soil KW - Multivariate methods KW - Feature selection PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-580777 DO - https://doi.org/10.3390/s23167178 VL - 23 IS - 16 SP - 1 EP - 17 PB - MDPI AG CY - Basel, Schweiz AN - OPUS4-58077 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Even, Morgane A1 - Juritsch, Elevtheria A1 - Richter, Matthias T1 - On the use of Carbograph 5TD as an adsorbent for sampling VVOCs: validation of an analytical method N2 - A standardised method for the analysis of very volatile organic compounds (VVOCs) in indoor air is still missing. This study evaluates the use of Carbograph 5TD as an adsorbent for 60 compounds (47 VVOCs + 13 VOCs) by comparing their recoveries with different spiking modes. The influence of the spiking of the tubes in dry nitrogen, humidified air or along the whole flushing duration mimicking real sampling was investigated. 49 substances (36 VVOCs from C1 to C6) had recoveries over 70% on the adsorbent in humidified air and were validated. The linearity of the calibration curves was verified for every spiking mode and the limits of detection (LOD) and quantification (LOQ) were determined. The LOQs were lower than the existing indoor air guideline values. The robustness of the method was considered by studying the influence of the sampling volume, the sampling flow rate, the humidity level and the storage of the tubes. In general, the most volatile or polar substances were the less robust ones. The combined measurement uncertainty was calculated and lies below 35% for a vast majority of the substances. An example of an emission chamber test using polyurethane foam is shown: Carbograph 5TD performs much better than Tenax® TA for VVOCs and emissions from n-butane were quantified with combined measurement uncertainty. KW - VVOC KW - Gas chromatography KW - Thermal desorption KW - Air sampling PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-581113 DO - https://doi.org/10.1039/D3AY00677H VL - 15 IS - 31 SP - 3810 EP - 3821 AN - OPUS4-58111 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 - Winckelmann, Alexander A1 - Roik, Janina A1 - Recknagel, Sebastian A1 - Abad Andrade, Carlos Enrique A1 - You, Zengchao T1 - Investigation of matrix effects in nitrogen microwave inductively coupled atmospheric-pressure plasma mass spectrometry (MICAP-MS) for trace element analysis in steels N2 - We investigated the performance of nitrogen microwave inductively coupled atmospheric-pressure plasma mass spectrometry (MICAP-MS) under matrix effects and its applicability to trace element analysis in steels. Influences of different gas flows and ion optics on the matrix tolerance are studied, indicating that nebulizer gas flow has the most significant impact. Optimization of ion optics improves matrix tolerance for light elements due to the reduction of the inelastic collisional scattering effect. With optimized operating conditions, MICAP-MS achieves an internal standard intensity recovery of over 90% at an Fe concentration of 500 mg L−1. Even at an Fe concentration of 1 g L−1, the recovery remains above 80%. Three certified reference materials – non-alloy, low-alloy and high-alloy steel – were analyzed using MICAP-MS. The determined mass concentrations of the trace and minor components show metrological compatibility to the reference values. No significant differences are observed between the results obtained with aqueous and matrix-matched calibration, demonstrating the strong matrix tolerance of MICAP-MS, and its promising applicability to steel analysis. KW - MICAP-MS KW - Trace Analysis KW - Steel PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-576323 DO - https://doi.org/10.1039/d3ja00088e SN - 0267-9477 VL - 38 IS - 6 SP - 1253 EP - 1260 PB - Royal Society of Chemistry AN - OPUS4-57632 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bornemann-Pfeiffer, Martin A1 - Meyer, Klas A1 - Lademann, J. A1 - Kraume, M. A1 - Maiwald, Michael T1 - Contributions towards variable temperature shielding for compact NMR instruments N2 - The application of compact NMR instruments to hot flowing samples or exothermically reacting mixtures is limited by the temperature sensitivity of permanent magnets. Typically, such temperature effects directly influence the achievable magnetic field homogeneity and hence measurement quality. The internal-temperature control loop of the magnet and instruments is not designed for such temperature compensation. Passive insulation is restricted by the small dimensions within the magnet borehole. Here, we present a design approach for active heat shielding with the aim of variable temperature control of NMR samples for benchtop NMR instruments using a compressed airstream which is variable in flow and temperature. Based on the system identification and surface temperature measurements through thermography, a model predictive control was set up to minimise any disturbance effect on the permanent magnet from the probe or sample temperature. This methodology will facilitate the application of variable-temperature shielding and, therefore, extend the application of compact NMR instruments to flowing sample temperatures that differ from the magnet temperature. KW - Benchtop NMR KW - Continuous Processes KW - Inline Analytics KW - Model Predictive Control KW - Process Analytical Tecnology KW - Temperature Control PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-579219 DO - https://doi.org/10.1002/mrc.5379 SN - 1097-458X SP - 1 EP - 10 PB - John Wiley & Sons Ltd. AN - OPUS4-57921 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - de Krom, I. A1 - Heikens, D. A1 - Horn, Wolfgang A1 - Wilke, Olaf A1 - Richter, Matthias A1 - Baldan, A. T1 - Metrological generation of SI-traceable gas-phase standards and reference materials for (semi-) volatile organic compounds N2 - EN 16516 sets specifications for the determination of emissions into indoor air from construction products. Reliable, accurate and International System of Unit (SI)-traceable measurement results of the emissions are the key to consumer protection. Such measurement results can be obtained by using metrologically traceable reference materials. Gas-phase standards of volatile organic compounds (VOCs) in air can be prepared by a variety of dynamic methods according to the ISO 6145 series. However, these methods are not always applicable for semi-VOCs (SVOCs) due to their high boiling point and low vapour pressure. Therefore, a novel dynamic gas mixture generation system has been developed. With this system gas-phase standards with trace level VOCs and SVOCs in air can be prepared between 10 nmol mol−1 and 1000 nmol mol−1. The VOCs and SVOCs in this study have normal boiling points ranging from 146 °C to 343 °C. Metrologically traceable reference materials of the gas-phase standard were obtained by sampling of the VOC gas-phase standard into Tenax TA® sorbent material in SilcoNert® coated stainless steel tubes. Accurately known masses between 10 ng and 1000 ng per VOC were sampled. These reference materials were used to validate the dynamic system. Furthermore, the storage and stability periods of the VOCs in the reference materials were determined as these are crucial characteristics to obtain accurate and SI-traceable reference materials. In a round robin test (RRT), the reference materials were used with the aim of demonstrating the feasibility of providing SI-traceable standard reference values for SVOCs for interlaboratory comparison purposes. Based on the results from the validation, the storage and stability studies and the RRT, gas-phase standards and reference materials of VOCs and SVOCs with relative expanded uncertainties between 5% and 12% (k = 2) have been developed. These reference standards can be used as calibrants, reference materials or quality control materials for the analysis of VOC emissions. KW - SVOC KW - Dynamic calibration gas mixtures KW - Reference materials KW - Indoor air KW - Thermal desorption PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-565978 DO - https://doi.org/10.1088/1361-6501/aca704 VL - 34 IS - 3 SP - 1 EP - 13 PB - IOP Publishing AN - OPUS4-56597 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tang, Chi-Long A1 - Seeger, Stefan A1 - Röllig, Mathias T1 - Improving the comparability of FFF-3D printing emission data by adjustment of the set extruder temperature N2 - Fused filament fabrication (FFF) is a material extrusion-based technique often used in desktop 3D printers. Polymeric filaments are melted and are extruded through a heated nozzle to form a 3D object in layers. The extruder temperature is therefore a key parameter for a successful print job but also one of the main emission driving factors as harmful pollutants (e.g., ultrafine particles) are formed by thermal polymer degradation. The awareness of potential health risks has increased the number of emission studies in the past years. However, studies usually refer their calculated emission data to the printer set extruder temperature for comparison purposes. In this study, we used a thermocouple and an infrared camera to measure the actual extruder temperature and found significant temperature deviations to the displayed set temperature among printer models. Our result shows that printing the same filament feedstocks with three different printer models and with identical printer set temperature resulted in a variation in particle emission of around two orders of magnitude. A temperature adjustment has reduced the variation to approx. one order of magnitude. Thus, it is necessary to refer the measured emission data to the actual extruder temperature as it poses a more accurate comparison parameter for evaluation of the indoor air quality in user scenarios or for health risk assessments. KW - Ultrafine particles KW - Infrared thermography KW - Thermocouple KW - Indoor air quality KW - FFF-3D printer PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-572842 DO - https://doi.org/10.1016/j.aeaoa.2023.100217 VL - 18 SP - 100217 PB - Elsevier Ltd. CY - Amsterdam, Niederlande AN - OPUS4-57284 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Balderas-Xicohtencatl, R. A1 - Villajos Collado, José Antonio A1 - Casabán, J. A1 - Wong, D. A1 - Maiwald, Michael A1 - Hirscher, M. T1 - ZIF‑8 Pellets as a Robust Material for Hydrogen Cryo-Adsorption Tanks N2 - Cryoadsorption on the inner surface of porous materials is a promising solution for safe, fast, and reversible hydrogen storage. Within the class of highly porous metal−organic frameworks, zeolitic imidazolate frameworks (ZIFs) show high thermal, chemical, and mechanical stability. In this study, we selected ZIF-8 synthesized mechanochemically by twin-screw extrusion as powder and pellets. The hydrogen storage capacity at 77 K and up to 100 bar has been analyzed in two laboratories applying three different measurement setups showing a high reproducibility. Pelletizing ZIF-8 increases the packing density close to the corresponding value for a single crystal without loss of porosity, resulting in an improved volumetric hydrogen storage capacity close to the upper limit for a single crystal. The high volumetric uptake combined with a low and constant heat of adsorption provides ca. 31 g of usable hydrogen per liter of pellet assuming a temperature−pressure swing adsorption process between 77 K − 100 bar and 117 K − 5 bar. Cycling experiments do not indicate any degradation in storage capacity. The excellent stability during preparation, handling, and operation of ZIF-8 pellets demonstrates its potential as a robust adsorbent material for technical application in pilot- and full-scale adsorption vessel prototypes. KW - Hydrogen adsorption storage KW - Metal−organic frameworks KW - ZIF-8 KW - Cryoadsorption KW - Hydrogen Storage KW - MefHySto PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-569473 DO - https://doi.org/10.1021/acsaem.2c03719 SN - 2574-0962 SP - 1 EP - 8 PB - ACS Publications CY - Washington DC AN - OPUS4-56947 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kubheka, G. A1 - Climent, Estela A1 - Tobias, Charlie A1 - Rurack, Knut A1 - Mack, J. A1 - Nyokong, T. T1 - Multiplexed Detection of Human Papillomavirus Based on AzaBODIPY-Doped Silica-Coated Polystyrene Microparticles N2 - Human papillomavirus (HPV) DNA detection can enable the early diagnosis of high-risk HPV types responsible for cervical cancer. HPV detection is also essential for investigating the clinical behavior and epidemiology of particular HPV types, characterization of study populations in HPV vaccination trials and monitoring the efficacy of HPV vaccines. In this study, two azaBODIPY dyes (1 and 2) were used as references and were doped into polystyrene particles (PS40), while a short HPV DNA single strand was used as a target molecule and was covalently bound to the silica shell. These particles were employed as optical probes in 1:1 hybridization assays, and their potential applicability as a tool for multiplex assays for the detection of different strands of HPV was evaluated using flow cytometry. A good separation in the fluorescence of the four different voncentrations prepared for each dye was observed. To perform the hybridization assays, HPV18, HPV16, HPV11 and HPV6 single strands were attached to the particles through EDC-mediated coupling. The c-DNA-1-PS40 and c-DNA-2-PS40 particles exhibited low limit of detection (LOD) and quantification (LOQ) values for HPV11, and a narrow detection range was obtained. Multiplexed assay experiments were successfully performed for both particles, and the results proved that c-DNA-1-PS40 could potentially be used as a tool for multiplexing assays and merits further in-depth study in this context. KW - Flow cytometry KW - BODIPY dyes KW - Core-shell particles KW - Multiplexed assay KW - Human papillomavirus PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-567358 DO - https://doi.org/10.3390/chemosensors11010001 SN - 2227-9040 VL - 11 IS - 1 SP - 1 EP - 21 PB - MDPI CY - Basel AN - OPUS4-56735 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 -