Auflistung nach Autor:in "Goedecke, Caroline"

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    A novel GC-MS method for the determination and quantification of metformin in surface water
    (2017) Goedecke, Caroline; Fettig, Ina; Piechotta, C.
    Drug therapy for diabetes mellitus has increased significantly in recent years. 1,1-Dimethylbiguanide hydrochloride (metformin) is the most common drug used for the treatment of diabetes. Metformin is not metabolized in the human body and enters the water cycle via sewage. A new gas chromatography-mass spectrometry (GC-MS) method has been developed which enables the quantification of metformin in surface water samples even at low concentrations in the ng L-1 range. A solid phase extraction (SPE) method for the preconcentration of metformin and the internal standard 1-butylbiguanide (buformin) was established, and the method parameters such as the composition and volume of the eluent were optimized. Derivatization of metformin and buformin was obtained by using n-methyl-bis (trifluoroacetamide) (MBTFA). The reaction conditions of the derivatization, such as the reaction temperature and volume of the derivatization agent, were evaluated. The limit of detection (LOD) and limit of quantification (LOQ) were determined to be 3.9 ng L-1 and 12 ng L-1 in surface water samples. Linearity was shown over a concentration range of 10-50 ng L-1. The good performance of the method was demonstrated by comparison with a liquid chromatography tandem mass spectrometry (LC-MS/MS) method. The results indicate that the GC-MS method is a reliable and sensitive alternative for the quantification of metformin in surface water. Quelle: http://pubs.rsc.org
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    Development of a routine screening method for the microplastic mass content in a wastewater treatment plant effluent
    (2022) Goedecke, Caroline; Eisentraut, Paul; Bannick, Claus Gerhard; Altmann, Korinna; Barthel, Anne-Kathrin; Obermaier, Nathan; Braun, Ulrike; Ricking, Mathias
    An investigation of microplastic (MP) occurrence in a municipal wastewater treatment plant (WWTP) effluent with tertiary treatment was carried out. Representative sample volumes of 1 m3 were taken by applying a fractionated filtration method (500, 100, and 50 (micro)m mesh sizes). The detection of MP mass fractions by thermal extraction desorption-gas chromatography/mass spectrometry (TED-GC/MS) was achieved without the previously required additional sample pretreatment for the first time. Different types of quantification methods for the evaluation of TED-GC/MS data were tested, and their accuracy and feasibility have been proven for real samples. Polyethylene, polystyrene, and polypropylene were identified in effluent samples. The polymer mass content varied significantly between 5 and 50 mg m-3. A correlation between the MP load and the quantity of suspended matter in the WWTP effluents, particle size distribution, particle type, and operation day (i.e., weekday, season, and capacity) was not found. It can be concluded that a meaningful assessment of WWTPs requires a comprehensive sampling campaign with varying operation conditions. © 2022 The Authors
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    Identification and Quantification of Microplastic in Sewage Systems by TED-GC-MS
    (2019) Altmann, Korinna; Goedecke, Caroline; Bannick, Claus Gerhard
    The number of publications reporting the amount of microplastic (MP) all over the world increased rapidly. Methods used so far are very time consuming and not able to provide information on total contents. As harmonised sampling, sample preparation and analysis strategies are missing different studies can hardly be compared and quantitative data, including identification and mass contents of the polymers found, are missing. This leads to a lack of comprehensive understanding of MP occurrence, source and entry pathways into the environment. We developed a method, Thermal Extraction/Desorption-Gaschromatography-Massspectrometry, as a fast screening method for MP analysis. Solid residues of water samples are heated up to 600 C under a N2 atmosphere without any sample preparation. The collected decomposition gases are separated in a gas chromatography system and detected in a mass spectrometer. Mass contents of the identified polymers can be calculated. In this presentation we will show first results from the influent of the wastewater treatment plant Kaiserslautern (Germany) and its combined sewage system as possibly entry pathway. In order to determine the relevance of wastewater split streams analysis of grey water will be conducted. Samples are fractionally filtered by a sieve cascade with mesh sizes of 500, 100, 50 Ìm. Quelle: https://opus4.kobv.de/
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    Identification of microplastic pathways within a typical European urban wastewater
    (2022) Altmann, Korinna; Goedecke, Caroline; Bannick, Claus-Gerhard; Braun, Ulrike
    n recent years, thermoextraction/desorption-gas chromatography/mass spec-trometry (TED-GC/MS) has been developed as a rapid detection method for thedetermination of microplastics (MP) mass contents in numerous environmen-tally relevant matrices and, in particular, for the measurement of polymers inwater samples without time-consuming sample preparation. The TED-GC/MSmethod was applied to investigate a typical European municipal wastewatersystem for possible MP masses. Such investigations are important in view of therecent revision of the Urban WastewaterTreatment Directive. Four differentrepresentative sampling sites were selected: greywater (domestic wastewaterwithout toilet), combined sewer, andinfluent and effluent of a wastewatertreatment plant (WWTP). All samples were collected by fractional filtration.Filtration was carried out over mesh sizes of 500, 100, 50, and in some cases,5 ÎÌm. Polyethylene (PE), polypropylene (PP), and polystyrene (PS) weredetected in all samples, with the PE fraction dominating in all cases. Styrene-butadiene rubber which serves as an indication of tire abrasion, was only foundin the influent of the WWTP. The highest MP mass contents were found in thecombined sewer, so MP can become a source of pollution during heavy rainevents when the capacity limits of the effluent are reached, and the pollutedeffluent is released uncontrolled into the environment. Based on the studies,MP retention from the WWTP could be estimated to be approximately 96%.Few trends in polymer type or mass contents were detected within the differentfractions of the samples or when comparing samples to each other. © 2023 The Authors.Applied Researchpublished by Wiley-VCH GmbH.
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    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, Ulrike
    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. © The Author(s) 2020
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    Specific adsorption sites and conditions derived by thermal decomposition of activated carbons and adsorbed carbamazepine
    (2020) Eisentraut, Paul; Dittmann, Daniel; Goedecke, Caroline; Braun, Ulrike; Ruhl, Aki Sebastian
    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. © The Author(s) 2020