Dokument-ID Dokumenttyp Autoren/innen Persönliche Herausgeber/innen Haupttitel Abstract Auflage Verlagsort Verlag Herausgeber (Institution) Erscheinungsjahr Titel des übergeordneten Werkes Jahrgang/Band ISBN Veranstaltung Veranstaltungsort Beginndatum der Veranstaltung Enddatum der Veranstaltung Ausgabe/Heft Erste Seite Letzte Seite URN DOI Lizenz Datum der Freischaltung OPUS4-57307 Zeitschriftenartikel Becker, Roland; Scholz, Philipp; Jung, Christian; Weidner, Steffen Thermo-Desorption Gas Chromatography-Mass Spectrometry for investigating the thermal degradation of polyurethanes 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. Royal Society for Chemistry 2023 Analytical Methods 1 6 10.1039/D3AY00173C 2023-04-17 OPUS4-59185 Zeitschriftenartikel Lisec, Jan; Recknagel, Sebastian; Prinz, Carsten; Vogel, Kristin; Koch, Matthias; Becker, Roland eCerto—versatile software for interlaboratory data evaluation and documentation during reference material production The statistical tool eCerto was developed for the evaluation of measurement data to assign property values and associated uncertainties of reference materials. The analysis is based on collaborative studies of expert laboratories and was implemented using the R software environment. Emphasis was put on comparability of eCerto with SoftCRM, a statistical tool based on the certification strategy of the former Community Bureau of Reference. Additionally, special attention was directed towards easy usability from data collection through processing, archiving, and reporting. While the effects of outlier removal can be flexibly explored, eCerto always retains the original data set and any manipulation such as outlier removal is (graphically and tabularly) documented adequately in the report. As a major reference materials producer, the Bundesanstalt für Materialforschung und -prüfung (BAM) developed and will maintain a tool to meet the needs of modern data processing, documentation requirements, and emerging fields of RM activity. The main features of eCerto are discussed using previously certified reference materials. Springer Science and Business Media LLC 2023 Analytical and Bioanalytical Chemistry 1 9 urn:nbn:de:kobv:b43-591851 10.1007/s00216-023-05099-3 https://creativecommons.org/licenses/by/4.0/deed.de 2023-12-20 OPUS4-55886 Zeitschriftenartikel Sichler, Theresa Constanze; Adam, Christian; Becker, Roland; Sauer, Andreas; Ostermann, Markus; Barjenbruch, M. Phosphorus determination in sewage sludge: comparison of different aqua regia digestion methods and ICP-OES, ICP-MS and photometric determination Phosphorus recycling from sewage sludge will be obligatory in Germany from 2029. Phosphorus content determination in sewage sludge is crucial to assess the prescribed recycling rates. Currently, German law regards sample preparation using aqua regia digestion in a microwave or under reflux conditions as well as instrumental phosphorus determination by ICP-OES, ICP-MS, or photometric determination with ammonium molybdate as equivalent. However, it is questionable whether these methods are indeed equivalent regarding phosphorus quantification in sludges near the limit of 20 g/kg for mandatory recycling. To answer this question, 15 sewage sludges of 11 different wastewater treatment plants were investigated with all permitted method (digestion and measurement) combinations. Moreover, one sewage sludge was also examined in an interlaboratory comparison (ILC) with 28 participants. This study shows that the above-mentioned methods differ in some cases significantly but across all method combinations and sludges, phosphorus recovery was between 80 and 121% after normalization to the grand mean (average of 15 sludges between 85 and 111%). The ILC and the examination of 15 sludges produced largely similar results. There is a tendency to higher phosphorus recovery after microwave digestion compared to reflux digestion and ICP-OES measurements determine higher phosphorus contents than ICP-MS and photometric phosphorus determination. As a result, the authors recommend ICP-OES determination of phosphorus in sewage sludge after microwave digestion. Springer 2022 Environmental Sciences Europe 34 99 1 14 urn:nbn:de:kobv:b43-558869 10.1186/s12302-022-00677-1 https://creativecommons.org/licenses/by/4.0/deed.de 2022-10-05 OPUS4-53740 Zeitschriftenartikel Ogrinc, N.; Rossi, A. M.; Durbiano, F.; Becker, Roland; Milavec, M.; Bogozalec Kosir, A.; Kakoulides, E.; Ozer, H.; Akcadag, F.; Goenaga-Infante, H.; Quaglia, M.; Mallia, S.; Umbricht, G.; O'Connor, G.; Guettler, B. Support for a European metrology network on food safety Food-MetNet 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. Elsevier 2021 Measurement: Sensors 18 1 4 10.1016/j.measen.2021.100285 2021-11-17 OPUS4-53742 Zeitschriftenartikel Becker, Roland; Heyn, L.; Jung, Christian Indoor exposure to airborne polycyclic aromatic hydrocarbons: A comparison of stir bar sorptive extraction and pump sampling Stir bar sorptive extraction (SBSE) was compared with standardized pump sampling regarding the prospects to assess airborne levels of polycyclic aromatic hydrocarbons (PAHs) in indoor environments. A historic railway water tower, which will be preserved as a technical monument for museum purposes, was sampled with both approaches because the built-in insulationmaterial was suspected to release PAHs to the indoor air. The 16 PAHs on the US EPA list were quantified using gas chromatography with mass spectrometric detection in filters from pump sampling after solvent extraction and on SBSE devices after thermal desorption. SBSEwas seen to sample detectable PAHmasseswith excellent repeatability and a congener pattern largely similar to that observed with pump sampling. Congener patterns were however significantly different from that in the PAH source because release from the insulation material is largely triggered by the respective congener vapor pressures. Absolute masses in the ng range sampled by SBSE corresponded to airborne concentrations in the ng L−1 range determined by pump sampling. Principle differences between SBSE and pump sampling as well as prospects of SBSE as cost-effective and versatile complement of pump sampling are discussed. John Wiley & Sons Ltd. 2021 Engineering Reports 3 12 1 10 urn:nbn:de:kobv:b43-537427 10.1002/eng2.12419 https://creativecommons.org/licenses/by-nc-nd/4.0/deed.de 2021-11-17 OPUS4-53579 Zeitschriftenartikel Dorgerloh, Ute; Becker, Roland; Riedel, Juliane; Hofmann, Andrea Comparison of gas- and liquid chromatography-mass spectrometry for trace analysis of anilines in groundwater Three chromatographic procedures were investigated regarding their potential for the quantification of aniline and 19 of its methylated and chlorinated derivatives in groundwater. These methods were based on liquid-liquid-extraction in combination with gas chromatography and single quadrupole mass spectrometry (GC/MS) according to German standard DIN 38407-16:1999 and its extension using tandem mass spectrometry (GC/MS-MS), both following liquid-liquid extraction, and as third alternative the direct injection of the water sample into a liquid chromatograph coupled to tandem mass spectrometry (LC/MS-MS). Results were compared using fortified water and real-world contaminated groundwater used in an interlaboratory comparison. It could be shown that GC/MS and GC/MS-MS yielded results deviating less than 10% from each other while all three procedure displayed quantification results deviating less than 15% from the intercomparison reference values in case of each analyte in the concentration range between 1 and 45 µg L-1. Though GC/MS-MS displays a ten-fold higher sensitivity than single quadrupole GC/MS, the precision of both methods in the concentration range was similar. LC/MS-MS has the advantage of no further sample preparation due to the direct injection and leads for methylanilines and meta-, para- substituted chloroanilines to results sufficiently equivalent to the standardised GC/MS method. However, LC/MS-MS is not suitable for ortho-chloroaniline derivates due to significantly lower ion yields than meta- and para-substituted chloroanilines. London Taylor & Francis 2021 International Journal of Environmental Analytical Chemistry 103 19 8465 8477 urn:nbn:de:kobv:b43-535793 10.1080/03067319.2021.1987423 https://creativecommons.org/licenses/by/4.0/deed.de 2021-10-25 OPUS4-51066 Zeitschriftenartikel Becker, Roland Non-invasive cancer detection using volatile biomarkers: Is urine superior to breath? 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. Elsevier Ltd. 2020 Medical Hypothesis 143 110060 10.1016/j.mehy.2020.110060 2020-07-30 OPUS4-50977 Zeitschriftenartikel Becker, Roland; Altmann, Korinna; Sommerfeld, Thomas; Braun, Ulrike Quantification of microplastics in a freshwater suspended organic matter using different thermoanalytical methods - outcome of an interlaboratory comparison 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. Elsevier B.V. 2020 Journal of Analytical and Applied Pyrolysis 148 1 6 10.1016/j.jaap.2020.104829 2020-07-06 OPUS4-48625 Zeitschriftenartikel Scholz, Philipp; Wachtendorf, Volker; Elert, Anna Maria; Falkenhagen, Jana; Becker, Roland; Hoffmann, Katrin; Resch-Genger, Ute; Tschiche, Harald; Reinsch, Stefan; Weidner, Steffen Scholz, Philipp Analytical toolset to characterize polyurethanes after exposure to artificial weathering under systematically varied moisture conditions Polyether and -ester urethanes (PU) were exposed to artificial weathering at 40 °C and artificial UV radiation in a weathering chamber. In 3 parallel exposures, humidity was varied between dry, humid, and wet conditions. Material alteration was investigated by various analytical techniques like size exclusion chromatography (SEC), liquid chromatography-infrared spectroscopy (LC-FTIR), thermal-desorption gas chromatography-mass spectrometry (TD-GC-MS), fluorescence mapping and dynamic mechanical analysis (DMA). Our results show that depending on the weathering conditions, different degradation effects can be observed. By means of SEC an initial strong decrease of the molar masses and a broadening of the mass distributions was found. After a material dependent time span this was followed by a plateau where molar mass changes were less significant. A minor moisture-dependent degradation effect was only found for polyester PU. Fluorescence measurements on two materials revealed an increase in the luminescence intensity upon weathering process reaching a saturation level after about 500 h. The changes in the optical properties observed after different exposure conditions and times were very similar. The TD-GC-MS data showed the fate of the stabilizers and antioxidant in the course of weathering. LC-FTIR measurements revealed a change in peak intensities and the ratio of urethane and carbonyl bands. Amsterdam Elsevier 2019 Polymer Testing 78 105996, 1 9 10.1016/j.polymertesting.2019.105996 2019-08-06 OPUS4-48418 Zeitschriftenartikel de Souza Machado, A. A.; Lau, C. W.; Kloas, W.; Bergmann, J.; Bachelier, J. B.; Faltin, E.; Becker, Roland; Görlich, A. S.; Rillig, M. C. Microplastics can change soil properties and affect plant performance 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. ACS 2019 Environmental Science and Technology 53 10 6044 6052 urn:nbn:de:kobv:b43-484181 10.1021/acs.est.9b01339 http://www.gesetze-im-internet.de/urhg/index.html 2019-07-08 OPUS4-48419 Zeitschriftenartikel Becker, Roland; Sauer, Andreas; Bremser, Wolfram Fifteen years of proficiency testing of total petrol hydrocarbon determination in soil: a story of success The total petrol hydrocarbon (TPH) content in soil is determined by gas chromatographic separation and flame ionisation detection according to ISO 16703 in routine laboratories for about 20 years. The development of the interlaboratory variability observed with this analytical procedure over 15 years in a proficiency testing scheme conducted annually with more than 170 participants is evaluated in detail. A significant improvement of the reproducibility standard deviation among participants is observed over the years and attributed to an increasing familiarity with the procedure. Nevertheless, the determination of TPH in the environmentally relevant mass fraction range between 500 mg/kg and 10 000 mg/kg in soils or sediments is far from reaching the reproducibility standard deviations predicted by the Horwitz curve. It is seen that laboratories with sporadic participation tend to report higher bias, while a core group of laboratories participating on a regular basis arrived at reproducibility standard deviations below 20 %. Results from a given laboratory obtained on two different samples tend to be highly correlated in the same PT round indicating a sound repeatability. Expectedly, the within-laboratory correlation between results from consecutive rounds was considerably lower. However, results from consecutive rounds with a temporal distance of 1, 2 or 3 years revealed largely similar correlations which suggests that the within-laboratory reproducibility adjusts to a constant level at least after a period of 1 year. Springer 2019 Accreditation and Quality Assurance 24 4 289 296 10.1007/s00769-019-01383-x 2019-07-08 OPUS4-49452 Posterpräsentation Becker, Roland Hinweis auf den Abbau von FCKW in kontaminiertem Grundwasser bis zur Difluoressigsäure (DFA) Ein Vergleich der Gehalte von Difluoressigsäure (DFA) und Trifluoressigsäure (TFA) in Regen- und Oberflächenwässern im Berliner Raum ergab ein TFA/DFA Verhältnis in Regenwasser von 10:1. Im Gegensatz dazu wies Grundwasser aus dem Einzugsbereich einer historischen Kontamination durch Fluorchlorkohlenwasserstoffe (FCKW) ein TFA/DFA-Verhältnis von 1:3 auf. Dies und die ungewöhnlich hohe DFA-Konzentration an dieser Stelle wird vor dem Hintergrund der beobachteten mikrobiellen Abbauprodukte des ursprünglichen eingetragenen FCKW 1,1,2-Trichlor-1,2,2-trifluorethan (R113) diskutiert. Eine mikrobielle Umwandlung des bekannten Abbauproduktes Chlortrifluorethylen (R1113) zur DFA wurde bislang nicht in Umweltkompartimenten beobachtet und wird hier auf Basis bekannter Stoffwechselwege vorgeschlagen. TFA wurde in Regenwasser, Oberflächenwasser und Grundwasser in vergleichbaren Größenordnungen von ca. 500 ng/L bestimmt. Im Gegensatz dazu wurde DFA in Grundwasserproben im Bereich der Schadstoffquelle der FCKW-Kontamination mit bis zu 2.000 ng/L nachgewiesen. Die Summe von TFA und DFA im Grundwasser korreliert nicht mit dem Eintrag aus Niederschlag und Oberflächenwasser. Darum liegt die Vermutung nahe, dass es für DFA andere Quellen als den direkten Eintrag oder den möglichen Abbauweg über TFA geben muss. DFA ist vermutlich ein Abbauprodukt von R1113. FCKWs, die im ersten Abbauschritt zu 1,1-Difluorethenen metabolisieren, stehen im Verdacht, in der Folge zu DFA zu hydrolysieren. Entscheidend scheint, dass bereits im Ausgangsprodukt ein CF2-Strukturelement enthalten ist, das dann zur Bildung von DFA führen kann. Somit würde aus dem ursprünglichen Eintrag des Kältemittels R113 über schrittweise Dechlorierung via 1,2-Dichlor-1,2,2-Trifluorethan (R123a) und R1113 die Bildung des beobachteten DFA folgen. Es ist also sinnvoll, DFA in die Diskussion zur Regulierung der Endprodukte des Abbaus fluorhaltiger Kälte- oder Lösungsmittel einzubeziehen. Die Ergebnisse wurden im Normausschuss Wasserwesen (NAW) des DIN vorgestellt und es soll ein Arbeitskreis gegründet werden, der ein Normverfahren zur Quantifizierung von TFA und DFA in Wasser erarbeitet. Interessierte Laboratorien sind herzlich eingeladen, die Normungsarbeit zu unterstützen. 2019 DEHEMA 21. Symposium Strategien zur Sanierung von Boden & Grundwasser 2019 Frankfurt a.M., Germany 25.11.2019 26.11.2019 2019-11-27 OPUS4-47556 Zeitschriftenartikel Dorgerloh, Ute; Becker, Roland; Kaiser, M. Evidence for the formation of difluoroacetic acid in chlorofluorocarbon-contaminated ground water The concentrations of difluoroacetic acid (DFA) and trifluoroacetic acid (TFA) in rainwater and surface water from Berlin, Germany resembled those reported for similar urban areas, and the TFA/DFA ratio in rainwater of 10:1 was in accordance with the literature. In contrast, nearby ground water historically contaminated with 1,1,2-trichloro-1,2,2-trifluoroethane (R113) displayed a TFA/DFA ratio of 1:3. This observation is discussed versus the inventory of microbial Degradation products present in this ground water along with the parent R113 itself. A microbial Transformation of chlorotrifluoroethylene (R1113) to DFA so far has not been reported for environmental media, and is suggested based on well-established mammalian metabolic pathways. Basel MDPI 2019 Molecules 24 6 1039, 1 6 urn:nbn:de:kobv:b43-475569 10.3390/molecules24061039 https://creativecommons.org/licenses/by/4.0/deed.de 2019-03-18 OPUS4-43889 Zeitschriftenartikel Dorgerloh, Ute; Becker, Roland; Nehls, Irene Volatile hydrocarbons in contaminated soil: Robustness of fractional quantification using headspace gas chromatography-mass-spectrometry 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. Taylor & Francis 2018 Soil and sediment contamination 27 1 1 12 10.1080/15320383.2018.1418287 2018-01-24 OPUS4-44524 Zeitschriftenartikel Sanchez-Martin, Pedro; Becker, Roland; Toepel, J.; Gorbushina, Anna An improved test for the evaluation of hydrocarbon degradation capacities of diesel-contaminating microorganisms The development of a test to evaluate the degradation of semi-volatile fuels as diesel by microorganisms is presented. This method is based on the principles described in the CEC-L-103 Standard procedure that is exclusively meant for testing the biodegradability of non-volatile lubricants. Therefore, significant modifications involve aseptic conditions for testing specific microorganisms and conducting the test in closed vessels avoiding evaporation losses, while fuel quantification using gas chromatography-flame ionization detection (GC-FID) is retained. It is suggested that the modified procedure should enable routine application for semi-volatile hydrocarbon-based fuels. GC-FID provides additionally valuable information on the alteration of fuel component patterns during biodegradation. The procedure was successfully tested using two bacteria (Pseudomonas aeruginosa and Sphingomonas sp.) and two yeasts (Moesziomyces sp. and Candida sp.) isolated from real diesel contamination cases. All tested microorganisms caused a significant degradation of diesel fuel achieving hydrocarbon degradation percentages ranging from 23% to 35%. Specific aspects on the test modification and prospects for further modification regarding targeted investigations in the field of fuel contamination by microorganisms are briefly discussed. Elsevier 2018 International Biodeterioration & Biodegradation 129 89 94 10.1016/j.ibiod.2018.01.009 2018-03-20 OPUS4-45405 Zeitschriftenartikel Paul, Andrea; Wander, Lukas; Becker, Roland; Goedecke, Caroline; Braun, Ulrike High-throughput NIR spectroscopic (NIRS) detection of microplastics in soil The increasing pollution of terrestrial and aquatic ecosystems with plastic debris leads to the accumulation of microscopic plastic particles of still unknown amount. To monitor the degree of contamination analytical methods are urgently needed, which help to quantify microplastics (MP). Currently, time-costly purified materials enriched on filters are investigated both by micro-infrared spectroscopy and/or micro-Raman. Although yielding precise results, these techniques are time consuming, and are restricted to the analysis of a small part of the sample in the order of few micrograms. To overcome these problems, here we tested a macroscopic dimensioned NIR process-spectroscopic method in combination with chemometrics. For calibration, artificial MP/soil mixtures containing defined ratios of polyethylene, polyethylene terephthalate, polypropylene, and polystyrene with diameters < 125 µm were prepared and measured by a process FT-NIR spectrometer equipped with a fiber optic reflection probe. The resulting spectra were processed by chemometric models including support vector machine regression (SVR), and partial least squares discriminant analysis (PLS-DA). Validation of models by MP mixtures, MP-free soils and real-world samples, e.g. and fermenter residue, suggest a reliable detection and a possible classification of MP at levels above 0.5 to 1.0 mass% depending on the polymer. The benefit of the combined NIRS chemometric approach lies in the rapid assessment whether soil contains MP, without any chemical pre-treatment. The method can be used with larger sample volumes and even allows for an online prediction and thus meets the demand of a high-throughput method. Springer 2018 Environmental Science and Pollution Research 26 8 7364 7374 10.1007/s11356-018-2180-2 2018-07-09 OPUS4-44990 Zeitschriftenartikel Mueller, Axel; Becker, Roland; Dorgerloh, Ute; Simon, Franz-Georg; Braun, Ulrike The effect of polymer aging on the uptake of fuel aromatics and ethers by microplastics 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. Amsterdam Elsevier 2018 Environmental Pollution 240 639 646 10.1016/j.envpol.2018.04.127 2018-05-24 OPUS4-44466 Zeitschriftenartikel Fischer-Tenhagen, C.; Johnen, D.; Nehls, Irene; Becker, Roland A Proof of Concept: Are Detection Dogs a Useful Tool to Verify Potential Biomarkers for Lung Cancer? Early and reliable diagnostic test is essential for effective therapy of lung cancer. Volatile organic compounds that are characteristic for cancer could serve as valuable biomarkers in cancer diagnosis. Both trace analytical and detection dog approaches give some evidence for the existence of such biomarkers. In this proof of concept, study dogs and trace analysis were implemented in combination to gain more information concerning cancer biomarkers. Two dogs were trained to distinguish between absorbed breath samples of lung cancer patients and healthy persons and succeeded with correct identification of patients with 9/9 and 8/9 and correct negative indications from of 8/10 and 4/10 samples from healthy individuals. A recent observational study found that breath samples from lung cancer patients showed an increase in 1-butanol, 2-butanone, 2-pentanone, and hexanal. Synthetic air samples were therefore fortified with these compounds and adsorbed to a fleece. Tested against breath samples from healthy probands, on presentation to the dogs these synthetic samples provoked an indication in three out of four samples. We were able to demonstrate that a combination of the natural nose of a dog and a trace analytic technique can be a valuable concept in the search for cancer biomarkers. Lausanne Frontiers Research Foundation 2018 Frontiers in Veterinary Science 5 Article 52,1 6 10.3389/fvets.2018.00052 2018-03-14 OPUS4-44881 Zeitschriftenartikel Becker, Roland; Sporkert, F.; Lô, I.; Baumgartner, M. The determination of ethyl glucuronide in hair: Experiences from nine consecutive interlaboratory comparison rounds 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. Elsevier 2018 Forensic Science International 288 67 71 10.1016/j.forsciint.2018.04.025 2018-05-14 OPUS4-45681 Vortrag Becker, Roland Querschnittsthema Referenzmaterialien: Planung Ringversuche 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. 2018 Forschungsschwerpunkt „Plastik in der Umwelt – Quellen • Senken • Lösungsansätze“: 2. Workshop des Querschnittsthemas „Analytik und Referenzmaterialien“ Augsburg, Germany 4.7.2018 4.7.2018 2018-08-10