TY - CONF A1 - Hantschke, Luisa Lamberta A1 - Westphalen, Tanja A1 - Kluge, Stephanie A1 - Kaminski, Katja A1 - Scholl, Juliane A1 - Koch, Matthias A1 - Piechotta, Christian T1 - Determination of background values of PFAS in representative soil samples in Germany N2 - Per- and polyfluoroalkyl substances (PFAS) are a large and ever-growing class of chemicals that are widely used. Due to the strength of the C-F bond, they do not decompose but accumulate in the environment posing a risk for nature and humans alike. While the use of some PFAS, like perfluorooctanoic acid (PFOA) and perfluorooctanoic sulfonic acid (PFOS) is already regulated in the EU, new ‘precursor’ substances are used to replace them. However, these precursors may be equally harmful to the environment. In recent years, many ‘hot spot’ sites with high PFAS contaminations in the soils have been distinguished,but no German-wide background values have been determined yet. Knowing these background values is crucial to understand the degree of PFAS contamination, underpinning future regulatory decisions. 600 soil samples are freshly taken at different sites all over Germany. PFAS are extracted from all samples. The extracts are analysed using LC-MS/MS with 30 PFAS as target compounds. Eluates are produced and analysed using targeted LC-MS/MS. To determine the amount of precursor substances not included in the targeted list, total oxidisable precursor (TOP) assays are performed with different approaches. Additionally, 50 samples taken at the same locations in 2012 are analysed to determine temporal trends of PFAS contamination. The determination of total extractable organically bound fluorine (EOF) is planned for comparison. The aim of the project is to obtain a broad overview of the status and development of the PFAS contamination in soil in Germany. By the preparation and analysis of eluates, the leaching behaviour of the analytes and thereby their mobility in the environment is investigated, helping to understand the transport of PFAS from contaminated soil to water. The use of different TOP assay methods allows to compare their results and usability in routine analysis, thereby giving insights into the amount of PFAS contamination hidden to targeted analysis and helping inspire future analysis strategies. The future comparison of these results to EOF analysis may further underline this point. The large number of samples and the geographic distribution of the sampling is unprecedented in Germany and allows to determine high-risk sites and ‘hot spots’. In the future, the insights from the project may be used as a guide for the political regulation of uses of PFAS. T2 - ANAKON23 CY - Vienna, Austria DA - 11.04.2023 KW - PFAS KW - Soil contamination KW - Background values KW - BBodSChV PY - 2023 AN - OPUS4-57755 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hantschke, Luisa Lamberta A1 - Steuernagel, Maximilian A1 - Westphalen, Tanja A1 - Kluge, Stephanie A1 - Kaminski, Katja A1 - Piechotta, Christian T1 - Comparison of three different TOP-Assay approaches for the determination of PFAS concentration in soil N2 - Per- and polyfluoroalkyl substances (PFAS) are a large, ever-growing and widely used class of chemicals. Due to the strength of the C-F bond, they do not decompose but accumulate in the environment posing a risk for nature and humans alike. While the use of some PFAS, like perfluorooctanoic acid (PFOA) is already regulated in the EU, new ‘precursor’ substances are used to replace them. However, these precursors may be equally harmful to the environment. In recent years, many ‘hot spot’ sites with high PFAS contaminations in soil have been distinguished, but no German-wide background values have been determined yet. Knowing these background values is crucial to understand the degree of PFAS contamination, underpinning future regulatory decisions. Due to the complexity and variety of different PFAS compounds, one needs to apply a broad spectrum of different techniques to capture most of the PFAS content in one sample. In the framework of this project, 600 soil samples are taken at different sites all over Germany. The concentration of 30 PFAS - 13 carboxylic acids (C4-C18), 5 sulfonic acids (C4-C10) and 12 precursor substances) - is determined in these soil samples using three different sample preparation approaches: 1) ultrasonic extraction of the soil samples with Methanol; 2) preparation of eluates to test the leaching behaviour of the PFAS and 3) TOP assays following the method published by Houtz & Sedlak. Targeted LC-MS/MS is used to determine PFAS concentration after all three preparation steps. For the TOP-assay, the concentration of all 30 PFAS is compared prior to and after the oxidation reaction. Besides the ‘classic’ TOP-Assay, two other TOP-Assay approaches, the dTOP Assay and the photoTOP-Assay, are tested and the results of all three approaches are compared. First, all three TOP-Assay approaches will be tested on a reference soil spiked with a solution including all 30 PFAS measured in the project. Later, soil samples taken in the frame of the priorly described project will be tested. This poster will focus on the results of the experiments comparing the three different TOP Assay approaches in spiked reference soil. Additionally, some of the results of the other sample preparation methods, extraction and eluate preparation will be presented. T2 - FLUOROS 2023 CY - Idstein, Germany DA - 31.08.2023 KW - PFAS TOP Assay soil contamination PY - 2023 AN - OPUS4-58267 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -