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 - Maiwald, Michael T1 - Metrologie für fortschrittliche Wasserstoffspeicherlösungen – Das EU-Projekt MefHySto T1 - Metrology for advanced hydrogen storage solutions – The EU project MefHySto N2 - Das europäische Projekt MefHySto befasst sich mit dem Bedarf an großmaßstäblichen Energiespeichern, die für eine Umstellung der Energieversorgung auf erneuerbare Energien erforderlich sind. Eine solche Speicherung ist entscheidend, um Energie zu Spitzenzeiten zu liefern, wenn die erneuerbaren Energiequellen schwanken. Eine mögliche Lösung für die Energiespeicherung ist der großtechnische Einsatz von Wasserstoff. Die messtechnische Rückführbarkeit in der Energieinfrastruktur für die Wasserstoffspeicherung ist dann von entscheidender Bedeutung und eine bessere Kenntnis der chemischen und physikalischen Eigenschaften von Wasserstoff sowie rückführbare Messungen und validierte Techniken unverzichtbar. N2 - The European project MefHySto addresses the need of large-scale energy storage, which is required for a shift to renewable energy supply. Such storage is mandatory to supply energy at peak times when renewable sources fluctuate. A possible solution for energy storage is large-scale use of hydrogen. Metrological traceability in the energy infrastructure for hydrogen storage is then crucial and a better knowledge of the chemical and physical properties of hydrogen as well as traceable measurements and validated techniques are indispensable. KW - Wasserstoff KW - Wasserstoffspeicher KW - Infrastruktur KW - Metrologie KW - PEM-Wasserelektrolyse KW - Rückverstromung KW - Lastwechsel KW - Wasserstoff-Qualität PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-556451 UR - https://gwf-gas.de/forschung-entwicklung/metrologie-fuer-fortschrittliche-wasserstoffspeicherloesungen-das-eu-projekt-mefhysto/ SN - 2366-9594 VL - 163 IS - 9 SP - 38 EP - 45 PB - Vulkan Verlag CY - Essen AN - OPUS4-55645 LA - deu 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 - Musyanovych, A. A1 - Grimmer, Christoph A1 - Sadak, A. E. A1 - Heßling, L. A1 - Lüdicke, M. A1 - Bilsel, M. A1 - Horn, Wolfgang A1 - Richter, Matthias T1 - Polymer Capsules with Volatile Organic Compounds as Reference Materials for Controlled Emission N2 - Encapsulation of volatile organic compounds (VOCs) that could evaporate at a defined rate is of immense interest for application in emission reference materials (ERMs). Polyurethane/polyurea microcapsules with various VOC active ingredients (limonene, pinene, and toluene) were successfully produced by interfacial polymerization with Shirasu porous glass membrane emulsification in a size range between 10 and 50 μm. The effect of surfactant, VOC, monomer(s) type, and ratio has a great effect on the formulation process and morphology of capsules. The type of VOC played a significant role in the encapsulation efficiency. Due to the difference in vapor pressure and VOC/water interfacial tension, the formulation for encapsulation was optimized for each individual VOC. Furthermore, to achieve effective stability of the large droplets/capsules, a combination of ionic and nonionic surfactants was used. Optical and scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA), were used to characterize the optimized microcapsules. The results showed that the obtained microcapsules exhibited a spherical shape and core–shell morphology and featured characteristic urethane-urea bonds. The amount of encapsulated VOC ranges between 54 and 7 wt %. The emission tests were performed with the help of the emission test chamber procedure (EN 16516). The limonene-loaded polyurethane/polyurea microcapsules show a change in emission rate of less than 10% within 14 days and can be considered as a potential candidate for use as an ERM. KW - Polymer microcapsules KW - Membrane emulsification KW - Polyaddition KW - Volatile organic compound (VOC) KW - Emission testing PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-619227 DO - https://doi.org/10.1021/acsami.4c12826 SN - 1944-8252 VL - 16 IS - 50 SP - 69999 EP - 70009 PB - ACS AN - OPUS4-61922 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Thiele, Isabel A1 - Weiske, Björn A1 - Riedel, Sebastian L. A1 - Meyer, Klas T1 - On-line monitoring of polyhydroxyalkanoate extraction by low-field nuclear magnetic resonance spectroscopy N2 - The use of low-field nuclear magnetic resonance (NMR) spectroscopy enables real-time reaction monitoring in contrast to time-consuming gas chromatography or off-line high-field NMR measurements. In this study, NMR spectroscopy is demonstrated as a novel process analytical technology (PAT) tool in the downstream processing of polyhydroxyalkanoate (PHA) biopolymers. On-line NMR spectroscopy measurements were performed using a Spinsolve 43 Carbon Ultra instrument in a fully automated mode with a flow-assembly based on PTFE tubing. Single-scan NMR spectra were acquired for real-time monitoring of the extraction process of the PHA copolymer poly(hydroxybutyrate-co-hydroxyhexanoate) with 13.5 mol.% hydroxyhexanoate [P(HB-co-13.5 mol.%HHx)] from Ralstonia eutropha biomass using chloroform or acetone as PHA solvents at lyophilized cell loadings of 20–120 g L􀀀 1. The reproducibility and reliability of low-field NMR spectroscopy was comparable to high-field NMR spectroscopy, with superior performance in terms of time. The correlation between the results of on-line monitoring using low-field NMR spectroscopy and off-line analysis using gas chromatography (GC) showed a correlation coefficient of >94 %. The versatility of low-field NMR spectroscopy for elucidating reaction kinetics, facilitating endpoint determination and accelerating extraction processes by maximizing solubility is highlighted as plateau values were reached within 6–10 min for chloroform and acetone, respectively. This novel low-field NMR spectroscopy application promotes a new monitoring approach for downstream PHA processing and supports process development and optimization. KW - Polyhydroxyalkanoate KW - Extraction KW - NMR KW - Ralstonia eutropha KW - Downstream processing PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-624215 DO - https://doi.org/10.1016/j.polymdegradstab.2025.111188 SN - 1873-2321 VL - 233 SP - 1 EP - 10 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-62421 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mervič, Kristina A1 - Azimzada, Agil A1 - Bayat, Mehmet Emin A1 - Šala, Martin A1 - Meermann, Björn T1 - CO2-based matrix-independent carbon quantification approach for single microplastic-ICP-MS analysis N2 - This study presents a new CO2-based, matrix-independent calibration approach for size determination of microplastic (MP) particles using single particle inductively coupled plasma-mass spectrometry (sp-ICP-MS). By incorporating a CO2 gas calibration approach and upon adjusting the flow rates, an accurate size determination of MPs between 2 and 7 μm was enabled. Scanning electron microscopy (SEM) was successfully applied for method validation. The CO2 gas calibration curves exhibited excellent linearity and reproducibility, with minimal matrix effects across different sample types and matrices, including river water and saline solutions. This CO2-based approach eliminates the limitations of matrix- and size-dependent calibrations, enabling robust and accurate size determinations of MPs. This advancement represents a significant step forward in the analytical capabilities for MPs, paving the way for improved environmental monitoring and assessment of plastic pollution. KW - sp-ICP-MS KW - Microplastic KW - New calibration strategy PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-633049 DO - https://doi.org/10.1007/s00216-025-05934-9 SN - 1618-2642 SP - 1 EP - 11 PB - Springer CY - Berlin AN - OPUS4-63304 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - 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 - Tobias, Charlie A1 - Gehrenkemper, Lennart A1 - Bernstein, Thomas A1 - Schlau, Sven A1 - Simon, Fabian A1 - Röllig, Mathias A1 - Meermann, Björn A1 - von der Au, Marcus T1 - Development of a fully automated slurry sampling introduction system for GF-AAS and its application for the determination of cadmium in different matrices N2 - element analysis, offering high sensitivity and precision. However, its effectiveness is limited by sample preparation challenges for solid samples like soils and microplastics. Traditional methods include sample preparation, such as digestion, which is time-consuming and involves reagents, like acids, contributing to measurement uncertainty and higher carbon footprints. Slurry sampling allows direct analysis of suspensions, offering a more efficient alternative. However, maintaining suspension stability is challenging, requiring robust autosampler systems to streamline the process and enhance analytical performance. Results: We present a novel autosampler extension for slurry sample introduction into GF-AAS. This system ensures suspension stability with a stirring device and closed vessels to prevent evaporation and contamination, incorporating a cooling unit to reduce solvent and analyte losses. It installs and removes in minutes without additional connections. Validation with cadmium analysis in BAM-U110 (Soil) and BAM-H010 (ABS) showed high reliability. For BAM-U110 (Soil), we achieved recovery rates of 94 % ± 13 % in water suspension. The recovery rate for BAM-H010 (ABS) was 104 % ±11 % in acetonitrile suspension. These results demonstrate the system’s robustness, versatility, and accuracy for different matrices. Significance: The autosampler extension helps solve key problems in trace element analysis of solid samples, making the process faster and more accurate. It works well with complex materials, making it useful for areas like microplastic or nanoparticle analysis. This improvement also helps meet regulations for monitoring environ mental and polymer samples, offering a reliable and flexible tool for high-throughput analysis with fewer errors. KW - Slurry AAS KW - Soil KW - Cd PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-618531 DO - https://doi.org/10.1016/j.aca.2024.343460 SN - 0003-2670 VL - 1335 SP - 1 EP - 7 PB - Elsevier BV AN - OPUS4-61853 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -