Person: Claßen, Daniela
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Gymnasiallehrerin
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Claßen
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Daniela
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Veröffentlichung Assessment of contaminants of emerging concern in European apex predators and their prey by LC-QToF MS wide-scope target analysis(2022) Gkotsis, Georgios; Badry, Alexander; Nika, Maria-Christina; Claßen, Daniela; Nikolopoulou, Varvara; Drost, Wiebke; Koschorreck, Jan; Treu, GabrieleApex predators are good indicators of environmental pollution since they are relatively long-lived and their high trophic position and spatiotemporal exposure to chemicals provides insights into the persistent, bioaccumulative and toxic (PBT) properties of chemicals. Although monitoring data from apex predators can considerably support chemicalsâ€Ì management, there is a lack of pan-European studies, and longer-term monitoring of chemicals in organisms from higher trophic levels. The present study investigated the occurrence of contaminants of emerging concern (CECs) in 67 freshwater, marine and terrestrial apex predators and in freshwater and marine prey, gathered from four European countries. Generic sample preparation protocols for the extraction of CECs with a broad range of physicochemical properties and the purification of the extracts were used. The analysis was performed utilizing liquid (LC) chromatography coupled to high resolution mass spectrometry (HRMS), while the acquired chromatograms were screened for the presence of more than 2,200 CECs through wide-scope target analysis. In total, 145 CECs were determined in the apex predator and their prey samples belonging in different categories, such as pharmaceuticals, plant protection products, per- and polyfluoroalkyl substances, their metabolites and transformation products. Higher concentration levels were measured in predators compared to prey, suggesting that biomagnification of chemicals through the food chain occurs. The compounds were prioritized for further regulatory risk assessment based on their frequency of detection and their concentration levels. The majority of the prioritized CECs were lipophilic, although the presence of more polar contaminants should not be neglected. This indicates that holistic analytical approaches are required to fully characterize the chemical universe of biota samples. Therefore, the present survey is an attempt to systematically investigate the presence of thousands of chemicals at a European level, aiming to use these data for better chemicals management and contribute to EU Zero Pollution Ambition. © 2022 The Authors.Veröffentlichung Fate of 14C-labelled ionic organic chemicals in a water-sediment system and surface water(2022) Holzmann, Hannah; Ackermann, Juliane; Claßen, DanielaThe persistence assessment of organic chemicals is based on neutral reference substances. Therefore, our study aimed at investigating the influence of a chemical charge on the degradation of organic compounds in a water-sediment system (OECD 308) and surface water (OECD 309). We used radiolabelled 4-n-dodecylbenzenesulfonic acid sodium salt (14C-DS-, anionic), 4-n-dodecylbenzyltrimethylammonium chloride (14C-DA+, cationic) and 4-n-dodecylphenol (14C-DP, non-ionic) which are structurally similar except their charges. After 120 days of incubation in a water-sediment system, 68% (14C-DS-), 6% (14C-DA+) and 63% (14C-DP) of the applied radioactivity (AR) were mineralized. The formation of non-extractable residues (NER) after 120 days was highest for 14C-DA+ (33% AR), followed by 14C-DS- (19% AR) and 14C-DP (14% AR). Dissipation half-lives (DT50) at 12 ˚C decreased as follows: 14C-DA+ (346 days) >> 14C-DS- (47 days) > 14C-DP (30 days). After 60 days of incubation in surface water with suspended sediment, mineralization of 14C-DS-, 14C-DA+ and 14C-DP accounted for 63%, 7% and 58% AR, respectively. Highest NER formation was observed for 14C-DP (21% AR), followed by 14C-DA+ (14% AR) and 14C-DS- (9% AR). DT50 (12 ˚C) decreased as follows: 14C-DA+ (45 days) > 14C-DP (3 days) > 14C-DS- (2 days). We showed that a positive charge reduces the degradability of organic chemicals in both test systems. From a scientific point of view, simulation studies following OECD 309 should always be complimented by tests with high sorption capacity, e.g. OECD 308 and OECD 307 tests in order to assess the degradation of a compound, especially in case of cationic organic compounds. © 2022 The Authors