TY - JOUR A1 - Wittwer, Philipp A1 - Roesch, Philipp A1 - Vogel, Christian A1 - Simon, Fabian A1 - Gehrenkemper, Lennart A1 - Feldmann, Ines A1 - Simon, Franz-Georg T1 - Less Is More: Influence of Cross-Linking Agent Concentration on PFOS Adsorption in Chitosan N2 - As a result of the continuous use of persistent per- and polyfluoroalkyl substances (PFAS), e.g., in aviation firefighting foams, contamination with PFAS has been found in soil, groundwater, and surface water around thousands of industrial and military installations. Due to their harmful (environmental) potential, further dispersion in the environment needs to be stopped, which can be achieved by appropriate absorption materials. In this work, the influence of the cross-linking agent epichlorohydrin (ECH) concentration on the perfluorooctanesulfonic acid (PFOS) adsorption capacity of chitosan gel was investigated. It was found that higher ECH concentration during the cross-linking step decreases the PFOS adsorption capacity of the cross-linked chitosan gel from 0% to 4% ECH solution by about 15%. Using a concentration of 1%, ECH resulted still in an acid-stable material, and a maximum PFOS loading capacity of 4.04 mmol/g was obtained, one of the highest described in the literature. Furthermore, we used a rapid small-scale column test to compare the PFOS adsorption capacity of chitosan and activated carbon, each in both milled and unmilled form. Unmilled chitosan showed the highest PFOS adsorption capacity considering adsorption material dry masses (>0.9 and <0.4 mmol/g for both types of chitosan and activated carbon, respectively). Milled activated carbon proved to be the better adsorption material, considering the fixed volume of the adsorber (>99.9% PFOS adsorbed). Overall, the cross-linking agent concentration in chitosan is a crucial factor influencing its PFOS absorption potential. Our results feature cross-linked chitosan as an effective economic and ecologic alternative for PFOS adsorption in aqueous solutions. KW - Combustion Ion Chromatography KW - Per- and Polyfluoroalkyl substances (PFAS) KW - Remediation PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-618406 DO - https://doi.org/10.3390/app142311145 VL - 14 IS - 23 SP - 1 EP - 13 PB - MDPI AN - OPUS4-61840 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Simon, Fabian T1 - Development of multi-layer SPE approaches for PFAS determination in surface water samples utilizing HR-CS-GFMAS N2 - Per- and polyfluoroalkyl substances (PFAS) have received global public attention because of their wide distribution in aquatic environments and potential adverse effects to humans and wildlife. Due to the lack of analytical standards and the enormous numbers of these compounds, current target-based methods (e.g., LC-MS/MS) are not suitable for the analysis of new/unknown PFAS and transformation products. Therefore, PFAS sum parameter analysis is becoming increasingly important. For PFAS determination of surface waters, solid phase extraction (SPE) is commonly implemented for clean-up and pre-concentration of samples. Thus, within this work, single-layer SPE methods (based on Strata™-X, Strata™-X-AW, Strata™-NH2 and Oasis-HLB) were investigated for maximum PFAS coverage utilizing extractable organically bound fluorine (EOF) analysis. Thereby, the optimization procedure relied on the analysis of 3 surface water samples in Berlin, Germany, which were affected by the effluent discharge of wastewater treatment plants. To analyse the SPE elution profiles for EOF and inorganic fluorine, high resolution-continuum source-graphite furnace molecular absorption spectroscopy (HR-CS-GFMAS) and ion chromatography (IC) were used, respectively. Highest EOF concentrations were achieved by using Strata-X/Strata-XAW as SPE sorbents and methanol as eluent. Furthermore, combinations of the most promising SPE sorbents were selected (X/XAW, XAW/X, HLB/X and WAX/GCB) to extract a wider range of PFASs. By comparing multi-layer SPE methods, lower EOF concentrations were obtained for all investigated combination phases compared to the analysed single phases. For the commercially available combination phase Strata-PFAS (WAX/GCB) for all three river water samples, lower EOF concentrations (1.5 times lower) were determined compared to Strata-X. The results have shown that single-layer SPE systems are currently superior compared to combination phases for PFAS sum parameter analysis. The multi-layer SPE methods need further optimization regarding appropriate sorbent combinations, loading volumes and elution conditions. The developed single-layer SPE methods can help to elucidate pollutions hotspots and discharge routes. T2 - Analytica Conference 2024 CY - Munich, Germany DA - 09.04.2024 KW - PFAS KW - HR-CS-GFMAS KW - Fluorine KW - SPE PY - 2024 AN - OPUS4-59890 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zweigle, Jonathan A1 - Simon, Fabian A1 - Meermann, Björn A1 - Zwiener, Christian T1 - Can Qualitative Nontarget Data Be Indicative of PFAS Contamination? First Evidence by Correlation with EOF in Environmental Samples N2 - We correlated nontarget screening (NTS) features and extractable organic fluorine (EOF) data for PFAS analysis in environmental samples. Soils, sediments, and ashes from different locations (Germany, France, and Lithuania) (n = 34) were analyzed via liquid chromatography-high-resolution mass spectrometry and high-resolution continuum source-graphite furnace molecular absorption spectrometry. NTS feature prioritization based on mass to carbon (m/C) and mass defect to carbon (MD/C) ratios was applied to discriminate potential PFAS features from common co-extracted organic matrix. Our results show a high correlation between quantitative EOF and the prioritized feature number (R2 = 0.87; rPearson = 0.93) and the total peak area of prioritized features (R2 = 0.97; rPearson = 0.98), while commonly applied MD ranges for filtering showed much weaker correlation with EOF. The observed correlations in PFAS-contaminated samples highlight that MD/C−m/C prioritization is associated with a good indication of the overall PFAS burden as evidenced by EOF. Also, semiquantitative data can be extracted as shown by EOF versus prioritized peak areas. The correlations indicate that weakly fluorinated compounds were negligible and that the EOF was mostly composed of highly fluorinated substances. Our method features the potential to automatically screen large NTS data sets for potential PFAS, determine the contribution of PFAS to EOF, and provide preliminary estimates of the overall PFAS burden. KW - PFAS KW - Non-target Screening KW - Sum parameter PY - 2024 DO - https://doi.org/10.1021/acs.estlett.4c00442 SN - 2328-8930 SP - 1 EP - 6 PB - American Chemical Society (ACS) AN - OPUS4-60754 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zweigle, J. A1 - Schmidt, A. A1 - Bugsel, B. A1 - Vogel, Christian A1 - Simon, Fabian A1 - Zwiener, C. T1 - Perfluoroalkyl acid precursor or weakly fluorinated organic compound? A proof of concept for oxidative fractionation of PFAS and organofluorines N2 - Organofluorine mass balance approaches are increasingly applied to investigate the occurrence of per- and polyfluoroalkyl substances (PFAS) and other organofluorines in environmental samples more comprehensively. Usually, complex samples prevent the identification and quantification of every fluorine-containing molecule. Consequently, large unidentified fractions between fluorine sum parameters such as extractable organic fluorine (EOF) and the sum of quantified analytes are frequently reported. We propose using oxidative conversion to separate (unidentified) weakly fluorinated compounds (e.g., pesticides, pharmaceuticals) from PFAA-precursors (perfluoroalkyl chain lengths ≥ C6). We show with three organofluorine model substances (flufenamic acid, diflufenican, pantoprazole) that CF3-groups or aromatic fluorine can be quantitatively converted to inorganic fluoride and trifluoroacetic acid (TFA) by applying PhotoTOP oxidation (UV/TiO2). The principle of fluorine separation in mixtures is demonstrated by the oxidation of the three weakly fluorinated compounds together with the PFAA-precursor 6:2/6:2 fluorotelomer mercaptoalkyl phosphate diester (FTMAP). After oxidation, the products F− and TFA were separated from PFCAs ( C4) by SPE, and the fractions were analyzed individually. Closed mass balances both with and without the addition of organic matrix were achieved. Eventually, the fluorine balance was verified by total fluorine measurements with combustion ion chromatography (CIC). The proposed methods should be considered a proof of concept to potentially explain unidentified fractions of the EOF, especially if compounds with low fluorine content such as pesticides, pharmaceuticals, and their transformation products contribute largely to the EOF. Future studies are needed to show the applicability to the complexity of environmental samples. Graphical Abstract KW - Combustion Ion Chromatography KW - Per- and Polyfluoroalkyl substances (PFAS) PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-613429 DO - https://doi.org/10.1007/s00216-024-05590-5 SP - 1 EP - 10 PB - Springer Science and Business Media LLC AN - OPUS4-61342 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Simon, Franz-Georg A1 - Pienkoß, Fabian T1 - INTEGRAL - Integriertes Konzept für mineralische Abfälle und Landmanagement zur nachhaltigen Entwicklung von Stadt-Land-Nutzungsbeziehungen, Teilvorhaben 4: BAM, Ermittlung stofflicher Parameter N2 - Zusammenfassend wurde in dieser Arbeit gezeigt, dass die Setzmaschinentechnik eine geeignete Methode ist, um Brechsande aus gemischten Bauabfällen aufzubereiten. Die Trennung des Materials in zwei Stoffströme unterschiedlicher Dichte hat sich mit einer Absenkung um 56% besonders effizient in der Reduzierung von PAK Belastungen im Feststoff erwiesen. Auch die Sulfatlast im Produktstrom wurde durch den Prozess im Vergleich zum Aufgabegut um 29% gesenkt. Neben der Erhöhung des Median Partikeldurchmessers durch Klassierungseffekte, ist die Herabsetzung verschiedener Eluatparameter ebenfalls positiv zu bewerten. Dies bezieht sich zum einen auf die elektrische Leitfähigkeit, die nach EBV von RC-3 auf RC-1 aufgewertet wurde und zum anderen auf die Chromkonzentration, die von RC-2 auf die Stufe RC-1 angehoben wurde. Die vorliegenden Aufbereitungsergebnisse erlaubten jedoch nicht eine Gesamteinordnung des Materials als Ersatzbaustoff oberhalb der Klasse RC-3. Hierzu ist eine weitere Absenkung der Eluatwerte für Sulfat um 25% von RC-3 (1325 mg L-1) auf RC-2 (< 1000 mg L-1) und des PAK-15 Wertes um 4% von RC-3 (8.3 µg L-1) auf RC-2 (< 8.0 µg L-1) erforderlich. Eine detaillierte Optimierung der Prozessparameter der Setzmaschinentechnik könnten diesen Spielraum ermöglichen. KW - Setzmaschine KW - Nassaufbereitung KW - Ersatzbaustoff PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-600263 DO - https://doi.org/10.2314/KXP:1887868135 N1 - Das diesem Bericht zugrunde liegende Vorhaben wurde mit Mitteln des Bundesministeriums für Bildung und Forschung unter dem Förderkennzeichen 033L223D gefördert SP - 1 EP - 18 PB - Technische Informationsbibliothek (TIB) CY - Hannover AN - OPUS4-60026 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -