TY - JOUR A1 - Dorgerloh, Ute A1 - Becker, Roland A1 - Nehls, Irene T1 - Volatile hydrocarbons in contaminated soil: Robustness of fractional quantification using headspace gas chromatography-mass-spectrometry N2 - Fuel contamination of soils display complex and variable hydrocarbon mixtures with different volatility and toxicity characteristics. A recently suggested headspace procedure for the structure-based quantification of volatile hydrocarbons is evaluated regarding repeatability, reproducibility, and practical robustness. Three aliphatic and three aromatic fractions covering the boiling range between 69 and 216°C were defined as summation parameters by their respective equivalent carbon number ranges. A standard mixture of 35 aliphatic and aromatic hydrocarbons was used for calibration on basis of selected mass fragments specific for the aliphatics and aromatics, respectively. Two standard soils were fortified with the standard mixture or different fuels, respectively, and submitted to the analytical procedure. Limit of detection (LOD) and limit of quantification (LOQ) were for all fractions lower than 0.1 and 0.3 mg/kg, respectively. Analyte recovery was linear up to between 20 and 110 mg hydrocarbons/kg soil depending on the fraction. Hydrocarbon recovery ranged between 80% and 110% depending on the fraction and the repeatability was typically better than 10%. Finally, the impact of extraction solvent variation, column solid-phase polarity, and alternative summation of fractions were investigated. The procedure was applied to liner samples taken from a site contaminated with aviation fuel and its practicability is discussed. KW - Gasoline KW - Contaminated site KW - Equivalent carbon number KW - Fuel KW - Static headspace PY - 2018 U6 - https://doi.org/10.1080/15320383.2018.1418287 SN - 1532-0383 SN - 1549-7887 VL - 27 IS - 1 SP - 1 EP - 12 PB - Taylor & Francis AN - OPUS4-43889 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Becker, Roland A1 - Scholz, Philipp A1 - Jung, Christian A1 - Weidner, Steffen T1 - Thermo-Desorption Gas Chromatography-Mass Spectrometry for investigating the thermal degradation of polyurethanes N2 - Thermo-Desorption Gas Chromatography-Mass Spectrometry (TD-GC-MS) was used to investigate the thermal degradation of two different polyurethanes (PU). PU samples were heated at different heating rates and the desorbed products were collected in a cold injection system and thereafter submitted to GC-MS. Prospects and limitations of the detection and quantification of semi-volatile degradation products were investigated. A temperature dependent PU depolymerization was found at temperatures above 200 °C proved by an increasing release of 1,4-butanediol and methylene diphenyl diisocyanate (MDI) representing the main building blocks of both polymers. Their release was monitored quantitatively based on external calibration with authentic compounds. Size Exclusion Chromatography (SEC) of the residues obtained after thermodesorption confirmed the initial competitive degradation mechanism indicating an equilibrium of crosslinking and depolymerization as previously suggested. Matrix-Assisted Laser Desorption Ionization (MALDI) mass spectrometry of SEC fractions of thermally degraded PUs provided additional hints on degradation mechanism. KW - Thermo-desorption KW - Mass spectrometry KW - Polyurethanes KW - Thermal degradation PY - 2023 U6 - https://doi.org/10.1039/D3AY00173C SN - 1759-9660 SP - 1 EP - 6 PB - Royal Society for Chemistry AN - OPUS4-57307 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mueller, Axel A1 - Becker, Roland A1 - Dorgerloh, Ute A1 - Simon, Franz-Georg A1 - Braun, Ulrike T1 - The effect of polymer aging on the uptake of fuel aromatics and ethers by microplastics N2 - Microplastics are increasingly entering marine, limnic and terrestrial ecosystems worldwide, where they sorb hydrophobic organic contaminants. Here, the sorption behavior of the fuel-related water contaminants benzene, toluene, ethyl benzene and xylene (BTEX) and four tertiary butyl ethers to virgin and via UV radiation aged polypropylene (PP) and polystyrene (PS) pellets was investigated. Changes in material properties due to aging were recorded using appropriate polymer characterization methods, such as differential scanning calorimetry, Fourier transform infrared spectroscopy, gel permeation chromatography, X-ray photoelectron spectroscopy, and microscopy. Pellets were exposed to water containing BTEX and the ethers at 130-190 mg/L for up to two weeks. Aqueous sorbate concentrations were determined by headspace gas chromatography. Sorption to the polymers was correlated with the sorbate's Kow and was significant for BTEX and marginal for the ethers. Due to substantially lower glass transition temperatures, PP showed higher sorption than PS. Aging had no effect on the sorption behavior of PP. PS sorbed less BTEX after aging due to an oxidized surface layer. KW - BTEX KW - Polypropylene KW - Polystyrene KW - Sorption KW - Degradation PY - 2018 U6 - https://doi.org/10.1016/j.envpol.2018.04.127 SN - 0269-7491 VL - 240 SP - 639 EP - 646 PB - Elsevier CY - Amsterdam AN - OPUS4-44990 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Becker, Roland A1 - Sporkert, F. A1 - Lô, I. A1 - Baumgartner, M. T1 - The determination of ethyl glucuronide in hair: Experiences from nine consecutive interlaboratory comparison rounds N2 - The increasing request for hair ethyl glucuronide (HEtG) in alcohol consumption monitoring according to cut-off levels set by the Society of Hair Testing (SoHT) has triggered a proficiency testing program based on interlaboratory comparisons (ILC). Here, the outcome of nine consecutive ILC rounds organised by the SoHT on the determination of HEtG between 2011 and 2017 is summarised regarding interlaboratory reproducibility and the influence of procedural variants. Test samples prepared from cut hair (1 mm) with authentic (in-vivo incorporated) and soaked (in-vitro incorporated) HEtG concentrations up to 80 pg/mg were provided for 27–35 participating laboratories. Laboratory results were evaluated according to ISO 5725-5 and provided robust averages and relative reproducibility standard deviations typically between 20 and 35% in reasonable accordance with the prediction of the Horwitz model. Evaluation of results regarding the analytical techniques revealed no significant differences between gas and liquid chromatographic methods In contrast, a detailed evaluation of different sample preparations revealed significantly higher average values in case when pulverised hair is tested compared to cut hair. This observation was reinforced over the different ILC rounds and can be attributed to the increased acceptance and routine of hair pulverisation among laboratories. Further, the reproducibility standard deviations among laboratories performing pulverisation were on average in very good agreement with the prediction of the Horwitz model. Use of sonication showed no effect on the HEtG extraction yield. KW - Ethyl glucuronide KW - Interlaboratory comparison KW - Proficiency testing KW - Society of hair testing KW - Reproducibility KW - Pulverization PY - 2018 U6 - https://doi.org/10.1016/j.forsciint.2018.04.025 SN - 0379-0738 SN - 1872-6283 VL - 288 SP - 67 EP - 71 PB - Elsevier AN - OPUS4-44881 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ogrinc, N. A1 - Rossi, A. M. A1 - Durbiano, F. A1 - Becker, Roland A1 - Milavec, M. A1 - Bogozalec Kosir, A. A1 - Kakoulides, E. A1 - Ozer, H. A1 - Akcadag, F. A1 - Goenaga-Infante, H. A1 - Quaglia, M. A1 - Mallia, S. A1 - Umbricht, G. A1 - O'Connor, G. A1 - Guettler, B. T1 - Support for a European metrology network on food safety Food-MetNet N2 - This paper describes Food-MetNet, a coordinated preparatory initiative to establish the European Metrology Network on Food Safety (EMN-FS). Food-MetNet aims to establish a long-term ongoing dialogue between the metrology community and relevant stakeholders, in particular, European Union Reference Laboratories (EURLs), National Reference Laboratories (NRLs) and the Joint Research Centre (JRC). This dialogue is meant to support the collection of needs from stakeholders, the take-up of metrological research output and the development of the roadmaps needed to navigate future research. KW - Network KW - Metrology KW - Food KW - Safety KW - Stakeholders PY - 2021 U6 - https://doi.org/10.1016/j.measen.2021.100285 VL - 18 SP - 1 EP - 4 PB - Elsevier AN - OPUS4-53740 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Becker, Roland A1 - Altmann, Korinna A1 - Braun, Ulrike T1 - Reference materials for microplastics in environmental matrices N2 - The pollution of marine, limnic and terrestrial environments with plastic waste and the potential impact especially on biota and humans has received increasing attention in recent years. Special focus is on particles smaller than 5 mm, the so-called microplastics. Consequently, possible regulations of emission and remediation efforts require sound information on the occurrence and fate of microplastics in the respective environmental compartments. Microplastics (MP) differ from classical organic pollutants in biota or the environment in that they do not consist of clearly defined low-molecular weight compounds but of polymer particulates with varying sizes and chemical compositions. This leads to specific challenges regarding the analytical techniques to be employed for their identification and quantification. Microplastics are defined as polymer particle in the size range between 1 µm and 5 mm and cover a wide range of polymers such as polyethylene, polypropylene, polystyrene and polyethylene terephthalate in variable geometric shapes. Properties relevant for environmental microplastics are polymer type, particle form and size distribution, surface morphology (aging status) and total mass fraction contained in a given sample. Polymer identification and particle size estimation using optical methods (IR and Raman spectroscopy) are time consuming and complicated by surface characteristics as a result of weathering, soiling, and microbial colonisation. Total mass fractions of MP in environmental samples can be determined by thermo-analytical methods. There are currently no standardised methods for sampling, sampling preparation, or detection of MP in environmental samples. So far, qualitative and quantitative investigations are done by research institutes and have not reached the routine laboratory community. The near future will see harmonisation efforts of MP mass fraction determination in environmental matrices by thermo-analytical procedures. The immediate need for reference materials during method development and comparison is outlined with regard to relevant matrix/polymer compositions, existing regulations and currently achievable detection limits. Examples for solid environmental matrix reference materials are discussed regarding the challenges encountered with matrices and polymer types as well as homogeneity testing and property value characterisation. T2 - BERM 2018 15th International Symposium on Biological and Environmental Reference Materials CY - Berlin, Germany DA - 23 September 2018 KW - Referenzmaterialien KW - Schwebstoffe KW - Sediment KW - Polymer PY - 2018 AN - OPUS4-46209 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Becker, Roland A1 - Altmann, Korinna A1 - Braun, Ulrike T1 - Querschnittsthema Referenzmaterialien: Planung Ringversuche N2 - Nach einer Erläuterung der international üblichen Definitionen von Referenzmaterialien und Matrix-Referenzmaterialien erfolgt eine Zusammenfassung der spezifischen Anforderungen bei Herstellung und Charakterisierung. Weiterhin werden die unterschiedlichen Anforderungen an die Durchführung von Ringversuchen im Sinne eines Methodenvergleiches, einer Eignungsprüfung von Laboratorien und der Zertifizierung von Matrix-Referenzmaterialien gegenübergestellt. Für den aktuell geplanten ersten Ringversuch zur Quantifizierung von Mikroplastik in Schwebstoffen mittels thermischer Verfahren werden die konkreten technischen Bedingungen zur Herstellung entsprechender Referenzmaterialien einschließlich der Homogenitätsprüfung ihrer Mikroplastikgehalte dargestellt. Die Besonderheiten des Ringversuches vor dem Hintergrund einer Normung der eingesetzten Verfahren werden diskutiert. T2 - Forschungsschwerpunkt „Plastik in der Umwelt – Quellen • Senken • Lösungsansätze“: 2. Workshop des Querschnittsthemas „Analytik und Referenzmaterialien“ CY - Augsburg, Germany DA - 4.7.2018 KW - Mikroplastik KW - Referenzmaterialien KW - Ringversuche KW - Thermische Verfahren KW - Schwebstoffe KW - Methodenvergleich PY - 2018 AN - OPUS4-45681 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Becker, Roland A1 - Altmann, Korinna A1 - Sommerfeld, Thomas A1 - Braun, Ulrike T1 - Quantification of microplastics in a freshwater suspended organic matter using different thermoanalytical methods – outcome of an interlaboratory comparison N2 - A sedimented freshwater suspended organic matter fortified with particles of polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyethylene terephthalate (PET) was employed in an interlaboratory comparison of thermoanalytical methods for microplastics identification and quantification. Three laboratories performed pyrolysis gas chromatography-mass spectrometry (Py-GC-MS), three others provided results using thermal extraction desorption followed by gas chromatography coupled to mass spectrometry (TED-GC-MS). One participant performed thermogravimetry-infrared spectroscopy (TGA-FTIR) and two participants used thermogravimetry coupled to mass spectrometry (TGA-MS). Further participants used differential scanning microscopy (DSC), a procedure based on micro combustion calorimetry (MCC) and a procedure based on elemental analysis. Each participant employed a different combination of sample treatment, calibration and instrumental Settings for polymer identification and quantification. Though there is obviously room for improvements regarding the between-laboratory reproducibility and the harmonization of procedures it was seen that the participants Performing Py-GC-MS, TED-GC-MS, and TGA-FTIR were able to correctly identify all polymers and to report reasonable quantification results in the investigated concentration range (PE: 20.0 μg/mg, PP: 5.70 μg/mg; PS: 2.20 μg/mg, PET: 18.0 μg/mg). Although for the other methods limitations exists regarding the detection of specific polymers, they showed potential as alternative approaches for polymer quantification in solid environmental matrices. KW - Interlaboratory comparison KW - Microplastics KW - Suspended organic matter KW - Pyrolysis PY - 2020 U6 - https://doi.org/10.1016/j.jaap.2020.104829 VL - 148 SP - 1 EP - 6 PB - Elsevier B.V. AN - OPUS4-50977 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Becker, Roland T1 - Non-invasive cancer detection using volatile biomarkers: Is urine superior to breath? N2 - In recent years numerous reports have highlighted the options of chemical breath analysis with regard to noninvasive cancer detection. Certain volatile organic compounds (VOC) supposedly present in higher amounts or in characteristic patterns have been suggested as potential biomarkers. However, so far no clinical application based on a specific set of compounds appears to exist. Numerous reports on the capability of sniffer dogs and sensor arrays or electronic noses to distinguish breath of cancer patients and healthy controls supports the concept of genuine cancer-related volatile profiles. However, the actual compounds responsible for the scent are completely unknown and there is no correlation with the potential biomarkers suggested on basis of chemical trace analysis. It is outlined that specific features connected with the VOC analysis in breath – namely small concentrations of volatiles, interfering background concentrations, considerable sampling effort and sample instability, impracticability regarding routine application - stand in the way of substantial progress. The underlying chemicalanalytical challenge can only be met considering the severe susceptibility of VOC determination to these adverse conditions. Therefore, the attention is drawn to the needs for appropriate quality assurance/quality control as the most important feature for the reliable quantification of volatiles present in trace concentration. Consequently, the advantages of urine as an alternative matrix for volatile biomarker search in the context of diagnosing lung and other cancers are outlined with specific focus on quality assurance and practicability in clinical chemistry. The headspace over urine samples as the VOC source allows adapting gas chromatographical procedures well-established in water analysis. Foremost, the selection of urine over breath as non-invasive matrix should provide considerably more resilience to adverse effects during sampling and analysis. The most important advantage of urine over breath is seen in the option to partition, dispense, mix, spike, store, and thus to dispatch taylor-made urine samples on demand for quality control measures. Although it is still open at this point if cancer diagnosis supported by non-invasively sampled VOC profiles will ultimately reach clinical application the advantages of urine over breath should significantly facilitate urgently required steps beyond the current proof-of-concept stage and towards standardisation. KW - VOC KW - Breath KW - Urine KW - Lung cancer KW - Volatile organic compounds PY - 2020 U6 - https://doi.org/10.1016/j.mehy.2020.110060 VL - 143 SP - 110060 PB - Elsevier Ltd. AN - OPUS4-51066 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - de Souza Machado, A. A. A1 - Lau, C. W. A1 - Kloas, W. A1 - Bergmann, J. A1 - Bachelier, J. B. A1 - Faltin, E. A1 - Becker, Roland A1 - Görlich, A. S. A1 - Rillig, M. C. T1 - Microplastics can change soil properties and affect plant performance N2 - Microplastics can affect biophysical properties of the soil. However, little is known about the cascade of events in fundamental levels of terrestrial ecosystems, i.e., starting with the changes in soil abiotic properties and propagating across the various components of soil−plant interactions, including soil microbial communities and plant traits. We investigated here the effects of six different microplastics (polyester fibers, polyamide beads, and four fragment types: polyethylene, polyester terephthalate, polypropylene, and polystyrene) on a broad suite of proxies for soil health and performance of spring onion (Allium fistulosum). Significant changes were observed in plant biomass, tissue elemental composition, root traits, and soil microbial activities. These plant and soil responses to microplastic exposure were used to propose a causal model for the mechanism of the effects. Impacts were dependent on particle type, i.e., microplastics with a shape similar to other natural soil particles elicited smaller differences from control. Changes in soil structure and water dynamics may explain the observed results in which polyester fibers and polyamide beads triggered the most pronounced impacts on plant traits and function. The findings reported here imply that the pervasive microplastic contamination in soil may have consequences for plant performance and thus for agroecosystems and terrestrial biodiversity. KW - Mikroplastik KW - Boden KW - Pflanzenwachstum PY - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-484181 SN - 0013-936X SN - 1520-5851 VL - 53 IS - 10 SP - 6044 EP - 6052 PB - ACS AN - OPUS4-48418 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -