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Veröffentlichung Analysis of polyethylene microplastics in environmental samples, using a thermal decomposition method(2015) Dümichen, Erik; Bannick, Claus Gerhard; Barthel, Anne-Kathrin; Braun, Ulrike; Brand, Kathrin; Jekel, Martin; Senz, RainerSmall 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.Quelle: http://www.sciencedirect.comVeröffentlichung The challenge in preparing particle suspensions for aquatic microplastic research(2019) Eitzen, Lars; Paul, Sophia; Braun, Ulrike; Ruhl, Aki SebastianThe occurrence of small particles consisting of organic polymers, so-called microplastic (MP), in aquatic environments attracts increasing interest in both public and science. Recent sampling campaigns in surface waters revealed substantial numbers of particles in the size range from a few micrometers to a few millimeters. In order to validate sample preparation, identification and quantification and to investigate the behavior of MP particles and potential toxic effects on organisms, defined MP model particles are needed. Many studies use spherical compounds that probably behave differently compared to irregularly shaped MP found in environmental samples. However, preparation and handling of MP particles are challenging tasks and have been systematically investigated in the present study. Polystyrene (PS) as a commonly found polymer with a density slightly above that of water was selected as polymer type for milling and fractionation studies. A cryogenic ball mill proved to be practical and effective to produce particles in the size range from 1 to 200 Ìm. The yield of small particles increased with increasing pre-cooling and milling durations. Depending on the concentration and the size, PS particles do not completely disperse in water and particles partly creep vertically up along glass walls. Stabilized MP suspensions without use of surfactants that might harm organisms are needed for toxicological studies. The stabilization of PS particle suspensions with ozone treatment reduced the wall effect and increased the number of dispersed PS particles but increased the dissolved organic carbon concentration and changed the size distribution of the particles. © 2018 Elsevier Inc. All rights reserved.Veröffentlichung Determination of microplastic mass content by thermal extraction desorption gas chromatography-mass spectrometry(2021) Wiesner, Yosri; Altmann, Korinna; Braun, UlrikeThe scientific and practical challenge of detecting microplastics (MPs) in the environment in a targeted and rapid manner is solved by innovative coupling of thermogravimetric analysis with mass spectrometric methods. Fast identification and quantitative determination of most thermoplastic polymers and elastomers is possible by using thermal extraction desorption gas chromatography-mass spectrometry (TED-GC-MS). © AuthorsVeröffentlichung Untersuchungsverfahren von Mikroplastikgehalten im Wasser für Praxis und Wissenschaft(2021) Altmann, Korinna; Braun, Ulrike; Heller, ClaudiaZielsetzung des vom Bundesministerium für Bildung und Forschung geförderten Projektes RUSEKU (Repräsentative Untersuchungsstrategien für ein integratives Systemverständnis von spezifischen Einträgen von Kunststoffen in die Umwelt) war es, repräsentative Untersuchungsstrategien für die Detektion von Mikroplastik mittels TED GC/MS in wässerigen Medien zu ermitteln. Dabei wurden verschiedene Probenahmekonzepte und -verfahren für unterschiedliche Fallgestaltungen und Fragestellungen untersucht, sowie neue Filtersysteme entwickelt. Bei der Detektion der Partikel lag der Fokus auf der Anwendung und Weiterentwicklung der ThermoExtraktion/Desorption-Gaschromatographie-Massenspektrometrie (TED-GC/MS) zur Bestimmung von Mikroplastikgehalten. Anwendung fanden die Methoden bei der Beprobung von Flaschenwasser, Waschmaschinenabläufen, dem urbanen Abwassersystem der Stadt Kaiserslautern, sowie in Oberflächengewässern. © AuthorsVeröffentlichung Smart filters for the analysis of microplastic in beverages filled in plastic bottles(2021) Braun, Ulrike; Altmann, Korinna; Herper, DominikThe occurrence of microplastic (MP) in food products, such as beverages in plastic bottles, is of high public concern. Existing analytical methods focus on the determination of particle numbers, requiring elaborate sampling tools, laboratory infrastructure and generally time-consuming imaging detection methods. A comprehensive routine analysis of MP in food products is still not possible. In the present work, we present the development of a smart filter crucible as sampling and detection tool. After filtration and drying of the filtered-off solids, a direct determination of the MP mass content from the crucible sample can be done by thermal extraction desorption gas chromatography mass spectroscopy (TED-GC/MS). The new filter crucible allows a filtration of MP down to particle sizes of 5 (micro)m. We determined MP contents below 0.01 (micro)g/L up to 2 (micro)g/L, depending on beverages bottle type. This may be directly related to the bottle type, especially the quality of the plastic material of the screw cap. Dependent on the plastic material, particle formation increases due to opening and closing operations during the use phase. However, we have also found that some individual determinations of samples were subjected to high errors due to random events. A conclusive quantitative evaluation of the products is therefore not possible at present. © Taylor&Francis OnlineVeröffentlichung Statuspapier Mikroplastikanalytik - Zusammenstellung wesentlicher Untersuchungsverfahren zur Probenahme, Aufbereitung und Detektion von Mikroplastik(2021) Braun, Ulrike; Stein, Ulf; Schritt, HannesUnter Mikroplastik sind Partikel, hauptsächlich bestehend aus synthetischen Polymeren, in der Dimension von 1-1000 (micro)m zu verstehen. Sie sind mittlerweile in der Umwelt allgegenwärtig, z.B. in Gewässern, Böden, Sedimenten und Luft, aber auch in Abwässern, Klärschlamm, Kompost und Lebensmitteln. In Umweltproben lassen sich in der Regel wenig große Partikel und sehr viele kleine Partikel von sehr unterschiedlicher Gestalt und chemischer Zusammensetzung identifizieren. Das macht ihre systematische Erfassung vergleichsweise aufwändig, sodass es eines guten Zusammenspiels verschiedener Verfahren bedarf. Obwohl die Charakterisierung von Plastik und von Partikeln seit Jahren etabliert ist, ist das Feld der Mikroplastikanalytik vergleichsweise jung. Daher müssen viele Verfahren erst noch hinsichtlich ihrer Eignung validiert werden. Es bestehen derzeit noch keine harmonisierten Protokolle. Das Statuspapier Mikroplastikanalytik fasst die Ergebnisse der Verbundprojekt-übergreifenden Diskussionen und Abstimmungen innerhalb des BMBF Forschungsschwerpunkts "Plastik in der Umwelt" zusammen. Es ist auf der Webseite des Forschungsschwerpunkts (https://www.bmbf-plastik.de/ index.php/de/publikationen) in deutscher und englischer Sprache zur Verfügung gestellt. © AuthorsVeröffentlichung Microplastic analysis using chemical extraction followed by LC-UV analysis: a straightforward approach to determine PET content in environmental samples(2020) Müller, Axel; Goedecke, Caroline; Eisentraut, Paul; Braun, UlrikeBackground 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. © The Author(s) 2020Veröffentlichung Decomposability versus detectability: First validation of TED-GC/MS for microplastic detection in different environmental matrices(2023) Kittner, Maria; Eisentraut, Paul; Braun, UlrikeA 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: 0.02wt% for polystyrene (PS), 0.04wt% for the tyre component styrene butadiene rubber (SBR) and 0.2wt% 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 (micro)g, SBR: 0.27-0.38 (micro)g, PP: 0.32-0.36 (micro)g, PMMA: 0.64-1.30 (micro)g, PET: 0.90-1.37 (micro)g, PE: 3.80-6.99 (micro)g) and their decompositions by radical scission processes were not significantly influenced by the matrices. In contrast, matrix-specific LOD increases of both biodegradable polymers PBAT (LOD: 1.41-7.18 (micro)g) and PLA (0.84-20.46 (micro)g) 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. © 2023 Wiley VCH GmbHVeröffentlichung A new concept for the ecotoxicological assessment of plastics under consideration of aging processes(2023) Kittner, Maria; Isernhinke, Lisa; Altmann, Korinna; Braun, Ulrike; Lukas, MarcusMicroplastics are widely distributed in aquatic and terrestrial environments, but up tonow less is known about (eco)toxicological impacts under realistic conditions. Researchso far has focused mainly on impacts on organisms by fresh, single-origin plasticfragments or beads. However, plastics found in the environment are complex incomposition, this means different polymer types and sources, with and withoutadditives and in all stages of age, and therefore, in a more or less advanced stage ofdegradation. For oxidized degradation products that might be released from plasticmaterials during aging, there is a lack of information on potentially adverse effects onaquatic biota. The latter is of particular interest as oxidized degradation products mightbecome more water soluble due to higher polarity and are more bioavailable, therefore.The present study focused on plastic leachates of polystyrene (PS) and polylactic acid(PLA), which were derived from alternating stress by hydrolysis and ultraviolet (UV)radiation-representing a realistic scenario in the environment. Test specimens of PS,PLA, or a PLA/PS layer (each 50%) were alternately exposed to UV radiation for 5 daysfollowed by hydrolysis for 2 days, for several weeks alternating. Ecotoxicological effectsof the storage water (artificial freshwater) of the test specimens and additionally, in asecond experimental setup, the effects of five potential polymer degradation productswere detected by 72 h algae growth inhibition tests withDesmodesmus subspicatus.Results clearly indicate inhibitory effects on algae growth by contaminants in thestorage water of stressed plastics with increasing growth inhibition of proceedinghydrolysis and UV stress times. Different polymers caused variable inhibitions of algaegrowth with stronger inhibitions by PS and less effects by PLA and the mixed layer ofboth. Moreover, not microplastic particles but the resulting dissolved degradationproducts after aging caused theecotoxicological effectsââą Ìwith strong effects by theoxidized degradation products. The existing data highlight the relevance of plastic agingas a framework for microplastic ecotoxicity evaluation and allow a proof of concept. © 2023 The Authors.Veröffentlichung Garment ageing in a Laundry care process under household-like conditions(2023) Heller, Claudia; Altmann, Korinna; Bannick, Claus Gerhard; Braun, Ulrike; Kerndorff, AlexanderThis study reflects typical consumer textile washing behaviour while taking into account existing standards in the household appliance and garment industries. Two garments were washed repeatedly with artificial dirt and detergent 30 times. The collected washing water was separated using fractional filtration. Textile physical tests were used to follow property changes of the garments, the microplastic release is determined using thermoextraction/desorbtionâ€Ìgas chromatography/mass spectrometry and the total organic carbon was measured as a sum parameter for the organic bonded carbon. This article shows the importance of a reality-based approach when investigating microplastics of textile origin in the laundry care process. Deposits of detergent and dirt on the textiles were detected. The total mass of sieve residues was much higher than the release of synthetic polymers. The cotton content of the garments causes a much higher fibre release than synthetic fibres. Both will lead to false results by purely gravimetric analysis because nonpolymer fibres will be included microplastic mass. The results cannot be generalised only by the main polymer type, knowledge of the textile construction must be included for final evaluation. © 2023 Wiley-VCH GmbH.