TY - JOUR A1 - Müller, Axel A1 - Goedecke, Caroline A1 - Eisentraut, Paul A1 - Piechotta, Christian A1 - Braun, Ulrike T1 - Microplastic analysis using chemical extraction followed by LC‑UV analysis: a straightforward approach to determine PET content in environmental samples N2 - Background: The ubiquitous occurrence of microplastic particles in marine and aquatic ecosystems was intensively investigated in the past decade. However, we know less about the presence, fate, and input paths of microplastic in terrestrial ecosystems. A possible entry path for microplastic into terrestrial ecosystems is the agricultural application of sewage sludge and solid bio-waste as fertilizers. Microplastic contained in sewage sludge also includes Polyethylene terephthalate (PET), which could originate as fiber from textile products or as a fragment from packaging products (foils, bottles, etc.). Information about microplastic content in such environmental samples is limited yet, as most of the used analytical methods are very time-consuming, regarding sample preparation and detection, require sophisticated analytical tools and eventually need high user knowledge. Results: Here, we present a simple, specific tool for the analysis of PET microplastic particles based on alkaline extraction of PET from the environmental matrix and subsequent determination of the monomers, terephthalic acid, using liquid chromatography with UV detection (LC-UV). The applicability of the method is shown for different types of PET in several soil-related, terrestrial environmental samples, e.g., soil, sediment, compost, fermentation residues, but also sewage sludge, suspended particles from urban water management systems, and indoor dust. Recoveries for model samples are between 94.5 and 107.1%. Limit of determination and limit of quantification are absolute masses of 0.031 and 0.121 mg PET, respectively. In order to verify the measured mass contents of the environmental samples, a method comparison with thermal extraction-desorption-gas chromatography–mass spectrometry (TED-GC/MS) was conducted. Both methods deliver similar results and corroborated each other. PET mass contents in environmental samples range from values below LOQ in agriculture soil up to 57,000 mg kg−1 in dust samples. Conclusions: We demonstrate the potential of an integral method based on chemical extraction for the Determination of PET mass contents in solid environmental samples. The method was successfully applied to various matrices and may serve as an analytical tool for further investigations of PET-based microplastic in terrestrial ecosystems. KW - Soil KW - Analysis KW - Microplastic KW - PET KW - LC-UV PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-509060 DO - https://doi.org/10.1186/s12302-020-00358-x IS - 32 SP - 85 PB - Springer Open CY - Berlin AN - OPUS4-50906 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dittmann, Daniel A1 - Eisentraut, Paul A1 - Goedecke, Caroline A1 - Wiesner, Yosri A1 - Jekel, M A1 - Ruhl, A S A1 - Braun, Ulrike T1 - Specific adsorption sites and conditions derived by thermal decomposition of activated carbons and adsorbed carbamazepine N2 - The adsorption of organic micropollutants onto activated carbon is a favourable solution for the treatment of drinking water and wastewater. However, these adsorption processes are not sufficiently understood to allow for the appropriate prediction of removal processes. In this study, thermogravimetric analysis, alongside evolved gas analysis, is proposed for the characterisation of micropollutants adsorbed on activated carbon. Varying amounts of carbamazepine were adsorbed onto three different activated carbons, which were subsequently dried, and their thermal decomposition mechanisms examined. The discovery of 55 different pyrolysis products allowed differentiations to be made between specific adsorption sites and conditions. However, the same adsorption mechanisms were found for all samples, which were enhanced by inorganic constituents and oxygen containing surface groups. Furthermore, increasing the loadings led to the evolution of more hydrated decomposition products, whilst parts of the carbamazepine molecules were also integrated into the carbon structure. It was also found that the chemical composition, especially the degree of dehydration of the activated carbon, plays an important role in the adsorption of carbamazepine. Hence, it is thought that the adsorption sites may have a higher adsorption energy for specific adsorbates, when the activated carbon can then potentially increase its degree of graphitisation. KW - Aktivkohle KW - TED-GC/MS KW - Adsorption KW - Thermoanalytik PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-506946 DO - https://doi.org/10.1038/s41598-020-63481-y VL - 10 IS - 1 SP - 6695 PB - Nature Publishing Group AN - OPUS4-50694 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Barthel, Anne-Kathrin A1 - Wesch, Ch. A1 - Braun, Ulrike A1 - Klein, R. A1 - Paulus, M. T1 - No microplastics in benthic eelpout (Zoarces viviparus): An urgent need for spectroscopic analyses in microplastic detection N2 - Monitoring the ingestion of microplastics is challenging and suitable detection techniques are insufficiently used. Thus, misidentifying natural for synthetic microfibres cannot be avoided. As part of a framework to monitor the ingestion of microplastics in eelpout, this short report addresses the accurate identification of microfibres. We show that, following visual inspections, putatively synthetic microfibres are indeed of natural origin, as ascertained by spectrometric analyses. Consequently, we call for an inclusion of spectroscopic techniques in standardized microplastic monitoring schemes. KW - Monitoring KW - Ingestion KW - Misidentification KW - Microfibre KW - Spectroscopy PY - 2016 DO - https://doi.org/10.1016/j.envres.2016.03.017 SN - 0013-9351 VL - 148 SP - 36 EP - 38 PB - Elsevier AN - OPUS4-35603 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dümichen, Erik A1 - Barthel, Anne-Kathrin A1 - Braun, Ulrike A1 - Bannick, Claus Gerhard A1 - Brand, K. A1 - Jekel, M. A1 - Senz, R. T1 - Analysis of polyethylene microplastics in environmental samples, using a thermal decomposition method N2 - Small polymer particles with a diameter of less than 5 mm called microplastics find their way into the environment from polymer debris and industrial production. Therefore a method is needed to identify and quantify microplastics in various environmental samples to generate reliable concentration values. Such concentration values, i.e. quantitative results, are necessary for an assessment of microplastic in environmental media. This was achieved by thermal extraction in thermogravimetric analysis (TGA), connected to a solid-phase adsorber. These adsorbers were subsequently analysed by thermal desorption gas chromatography mass spectrometry (TDS-GC-MS). In comparison to other chromatographic methods, like pyrolyse gas chromatography mass spectrometry (Py-GC-MS), the relatively high sample masses in TGA (about 200 times higher than used in Py-GC-MS) analysed here enable the measurement of complex matrices that are not homogenous on a small scale. Through the characteristic decomposition products known for every kind of polymer it is possible to identify and even to quantify polymer particles in various matrices. Polyethylene (PE), one of the most important representatives for microplastics, was chosen as an example for identification and quantification. KW - Microplastic KW - Identification and quantification of polymers KW - Thermogravimetric analysis KW - Evolved gas analysis KW - Gas chromatography mass spectroscopy PY - 2015 DO - https://doi.org/10.1016/j.watres.2015.09.002 SN - 0043-1354 VL - 85 SP - 451 EP - 457 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-34337 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dümichen, Erik A1 - Braun, Ulrike A1 - Kraemer, R. A1 - Deglmann, P. A1 - Senz, R. T1 - Thermal extraction combined with thermal desorption: A powerful tool to investigate the thermo-oxidative degradation of polyamide 66 materials N2 - Using thermogravimetric analysis (TGA) with a solid-phase adsorber for thermal extraction, followed by subsequently analysing the adsorber with thermo-desorption gas chromatography mass spectrometry (TDS-GC–MS) enables measurement of polymer degradation under oxidizing atmosphere, and the identification of certain complex hydrocarbon degradation products by chromatographic separation and defined mass patterns. This technique, thermal-extraction desorption gas chromatography mass spectrometry (TED-GC–MS) was used to investigate the thermo-oxidative degradation of PA 66 and PA 66 doped with 2 wt% of metal oxide particles. In TGA pure PA 66 formed more residue under an oxidizing atmosphere than an inert one. In contrast to the measurements under inert atmosphere, several condensed aromatic species containing nitrogen could be identified in thermo-oxidative measurements. These degradation products were formed through condensation reactions of primary amides originating from imide hydrolysis. The formation of such highly condensed species also causes higher char formation. Four metal oxides have shown an impact on the thermo-oxidative degradation of PA 66: Fe2O3 on η-Al2O3 < pure Fe2O3 = Fe2O3 on γ-Al2O3 < pure ZnO. For ZnO even a char-stabilizing effect could be observed. A catalytic effect of these metal oxides causes more condensed cyclopentanone and pyridine derivates. Thus, more water is formed and released, resulting in increased hydrolysis of the imides and degradation at lower temperatures. KW - PA 66 KW - Metal oxide particles KW - Thermo-oxidation KW - Thermogravimetry KW - Solid-phase extraction PY - 2015 DO - https://doi.org/10.1016/j.jaap.2015.08.006 SN - 0165-2370 SN - 1873-250X VL - 115 SP - 288 EP - 298 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-34338 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wildgruber, M. A1 - Lueg, C. A1 - Borgmeyer, S. A1 - Karimov, I. A1 - Braun, Ulrike A1 - Kiechle, M. A1 - Meier, R. A1 - Koehler, M. A1 - Ettl, J. A1 - Berger, H. T1 - Polyurethane versus silicone catheters for central venous port devices implanted at the forearm N2 - Purpose: We aimed to analyse short and long-term complications of polyurethane (PU) versus silicone catheters used in totally implantable venous-access ports (TIVAPs) implanted at the forearm. Methods: Retrospective analysis of 698 consecutively implanted TIVAPs was performed. Primary end-points were defined as rates of major complications associated with either type of central venous port catheter. Technical success rate, device service interval as well as minor complications not requiring port explantation were defined as secondary end-points. Results: A total of 698 port devices were implanted in 681 patients, 396 equipped with a PU catheter, 302 with a silicone catheter. The technical success rate was 99.9% with no major periprocedural complications. During follow-up a total of 211 complications in 146 patients were observed (1.0/1000 catheter days), 183 occurred associated with PU catheters (1.8/100 catheter days), 28 (0.3/1000 catheter days) with silicone catheters (log rank test p < 0.0001). Catheter-related bloodstream infections as well as thrombotic complications occurred significantly more frequently with PU catheters, while silicone catheters exhibited a trend towards a higher rate of mechanical failure such as disconnection or catheter rupture. Major complications requiring explantation of the device occurred more frequently with PU-based catheters (10.6%) compared to silicone catheter carrying ports (4.6%, log rank test p < 0.001). KW - Chemotherapy KW - Central venous access port KW - Complication KW - Thrombosis KW - Infection PY - 2016 DO - https://doi.org/10.1016/j.ejca.2016.02.011 SN - 0959-8049 VL - 59 SP - 113 EP - 124 PB - Elsevier Ltd. CY - Oxford, UK AN - OPUS4-36288 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Secker, C. A1 - Brosnan, S.M. A1 - Limberg, F.R.P. A1 - Braun, Ulrike A1 - Trunk, M. A1 - Strauch, P. A1 - Schlaad, H. T1 - Thermally induced crosslinking of poly(N-propargyl glycine) N2 - As polypeptoids become increasingly popular, they present a more soluble and processable alternative to natural and synthetic polypeptides; the breadth of their potential functionality slowly comes into focus. This report analyzes the ability of an alkyne-functionalized polypeptoid, poly(N-propargyl glycine), to crosslink upon heating. The crosslinking process is analyzed by thermal analysis (differential scanning calorimetry and thermogravimetric analysis), Fourier-transform infrared, electron paramagnetic resonance, and solid-state NMR spectroscopy. While a precise mechanism cannot be confidently assigned, it is clear that the reaction proceeds by a radical mechanism that exclusively involves the alkyne functionality, which, upon crosslinking, yields alkene and aromatic products. KW - Fourier-transform infrared KW - Metal-free crosslinking KW - Polypeptoid KW - Propargyl KW - Solid-state NMR PY - 2015 DO - https://doi.org/10.1002/macp.201500223 SN - 1022-1352 SN - 1521-3935 VL - 216 IS - 21 SP - 2080 EP - 2085 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-35265 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Klöckner, P. A1 - Seiwert, B. A1 - Eisentraut, Paul A1 - Braun, Ulrike A1 - Reemtsma, T. A1 - Wagner, S. T1 - Characterization of tire and road wear particles from road runoffindicates highly dynamic particle properties N2 - Tire and road wear particles (TRWPs) are heteroagglomerates of tire rubber and other particles deposited on the road surface and one of the main contributors to non-exhaust emissions of automobile traffic. In this study, samples from road environments were analyzed for their TRWP contents and concentra- tions of eight organic tire constituents. TRWP concentrations were determined by quantifying Zn in the density fraction < 1.9 g/cm ³and by thermal extraction desorption-gas chromatography-mass spectrometry (TED-GC/MS) and the concentrations ranged from 3.7 to 480 mg TRWP/g. Strong and statistically signif- icant correlations with TRWPs were found for 2-hydroxybenzothiazole and 2-aminobenzothiazole, indi- cating that these substances may be suitable markers of TRWPs. The mass distribution of TRWPs in road dust suggests that the main mass fraction formed on roads consists of coarse particles ( > 100 μm). Data for a sedimentation basin indicate that the fine fraction ( < 50 μm) is preferentially transported by road runoffinto receiving waters. The size distribution and density data of TRWP gathered by three different quantitation approaches also suggest that aging of TRWPs leads to changes in their particle density. An improved understanding of the dynamics of TRWP properties is essential to assess the distribution and dissipation of this contaminant of emerging concern in the environment. KW - Tire Wear KW - Density separation KW - Microplastic KW - Urban PY - 2020 DO - https://doi.org/10.1016/j.watres.2020.116262 VL - 185 SP - 116262 PB - Elsevier Ltd. AN - OPUS4-51256 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Goedecke, Caroline A1 - Dittmann, Daniel A1 - Eisentraut, Paul A1 - Wiesner, Yosri A1 - Schartel, Bernhard A1 - Klack, Patrick A1 - Braun, Ulrike T1 - Evaluation of thermoanalytical methods equipped with evolved gas analysis for the detection of microplastic in environmental samples N2 - Microplastic particles are currently detected in almost all environmental compartments. The results of detection vary widely, as a multitude of very different methods are used with very different requirements for analytical validity. In this work four thermoanalytical methods are compared and their advantages and limitations are discussed. One of them is thermal extraction-desorption gas chromatography mass spectrometry (TED-GC/MS), an analysis method for microplastic detection that has become established in recent years. In addition, thermogravimetric analysis coupled with Fourier-transform infrared spectroscopy (TGA-FTIR) and mass spectrometry (TGA-MS) were applied, two methods that are less common in this field but are still used in other research areas. Finally, microscale combustion calorimeter (MCC) was applied, a method not yet used for microplastic detection. The presented results are taken from a recently published interlaboratory comparison test by Becker et al. (2020). Here a reference material consisting of suspended matter and specified added polymer masses was examined, and only the results of the recoveries were presented. In the present paper, however, the results for the individual polymers are discussed in detail and individual perspectives for all instruments are shown. It was found that TED-GC/MS is the most suitable method for samples with unknown matrix and unknown, variable kinds and contents of microplastic. TGA-FTIR is a robust method for samples with known matrix and with defined kinds of microplastic. TGA-MS may offer a solution for the detection of PVC particles in the future. MCC can be used as a very fast and simple screening method for the identification of a potential microplastic load of standard polymers in unknown samples. KW - Microplastic KW - TED-GC/MS KW - TGA-MS KW - TGA-FTIR KW - MCC KW - Thermal analysis PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-516687 DO - https://doi.org/10.1016/j.jaap.2020.104961 VL - 152 SP - 104961 PB - Elsevier B.V. AN - OPUS4-51668 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kittner, Maria A1 - Eisentraut, Paul A1 - Dittmann, Daniel A1 - Braun, Ulrike T1 - Decomposability versus detectability: First validation of TED‐GC/MS for microplastic detection in different environmental matrices N2 - A fast method for microplastic detection is thermal extraction desorption‐gas chromatography/mass spectrometry (TED‐GC/MS), which uses polymer‐specific thermal decomposition products as marker compounds to determine polymer mass contents in environmental samples. So far, matrix impacts of different environmental matrices on TED‐GC/MS performance had not yet been assessed systematically. Therefore, three solid freshwater matrices representing different aquatic bodies with varying organic matter contents were spiked with a total of eight polymers. Additionally, for the first time, the two biodegradable polymers polybutylene adipate terephthalate (PBAT) and polylactide (PLA) were analysed using TED‐GC/MS. The methodological focus of this work was on detectability, quality of signal formation as well as realisation of quantification procedures and determination of the limit of detection (LOD) values. Overall, TED‐GC/MS allowed the unambiguous detection of the environmentally most relevant polymers analysed, even at low mass contents: 0.02 wt% for polystyrene (PS), 0.04 wt% for the tyre component styrene butadiene rubber (SBR) and 0.2 wt% for polypropylene (PP), polyethylene (PE) and PBAT. Further, all obtained LOD values were increased in all matrices compared to the neat polymer without matrix. The LOD of the standard polymers were increased similarly (PS: 0.21–0.34 μg, SBR: 0.27–0.38 μg, PP: 0.32–0.36 μg, PMMA: 0.64–1.30 μg, PET: 0.90–1.37 μg, PE: 3.80–6.99 μg) and their decompositions by radical scission processes were not significantly influenced by the matrices. In contrast, matrixspecific LOD increases of both biodegradable polymers PBAT (LOD: 1.41–7.18 μg) and PLA (0.84–20.46 μg) were observed, probably due to their hetero‐functional character and interactions with the matrices. In conclusion, the TED‐GC/MS performance is not solely determined by the type of the polymers but also by the composition of the matrix. KW - TED-GC/MS KW - Microplastic KW - Freshwater matrices KW - Gas chromatography KW - Mass spectrometry PY - 2023 DO - https://doi.org/10.1002/appl.202200089 SN - 2702-4288 VL - 2 IS - 3 SP - 1 EP - 12 PB - Wiley-VCH CY - Weinheim AN - OPUS4-57419 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -