Evidence for High Concentrations and Maternal Transfer of Substituted Diphenylamines in European Eels Analyzed by Two-Dimensional Gas Chromatography–Time-of-Flight Mass Spectrometry and Gas Chromatography–Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Abstract

Chemical pollution is hypothesized to be one of the factors driving the strong decline of the critically endangered European eel population. Specifically, the impact of contaminants on the quality of spawning eels and subsequent embryo survival and development has been discussed as crucial investigation point. However, so far, only very limited information on potential negative effects of contaminants on the reproduction of eels is available. Through the combination of nontargeted ultrahigh-resolution mass spectrometry and multidimensional gas chromatography, combined with more-conventional targeted analytical approaches and multimedia mass-balance modeling, compounds of particular relevance, and their maternal transfer in artificially matured European eels from the German river Ems have been identified. Substituted diphenylamines were, unexpectedly, found to be the primary organic contaminants in the eel samples, with concentrations in the μg g wet weight range. Furthermore, it could be shown that these contaminants, as well as polychlorinated biphenyls (PCBs), organochlorine pesticides, and polyaromatic hydrocarbons (PAHs), are not merely stored in lipid rich tissue of eels but maternally transferred into gonads and eggs. The results of this study provide unique information on both the fate and behavior of substituted diphenylamines in the environment as well as their relevance as contaminants in European eels.

Gas Chromatography-(Cyclic) Ion Mobility Mass Spectrometry: A Novel Platform for the Discovery of Unknown Per-/Polyfluoroalkyl Substances

“…Such plots help guide the search for homologous fluorinated, brominated, and chlorinated POPs, whose molecular and fragment ions are characterized by an exact mass that is smaller than the nominal mass. This has led to the identification of previously unknown (mixed) halogenated POPs in a wide range of environmental media, including freshwater and marine biota, , air, and dust . Unlike chlorinated and brominated compounds that display characteristic isotope patterns, polyfluorinated compound ions are more difficult to recognize because 19 F exists as a single stable isotope.…”

Synthetic Antioxidants as Contaminants of Emerging Concern in Indoor Environments: Knowns and Unknowns

“…Synthetic antioxidants are an enormous family of anthropogenic chemicals, and many commonly used antioxidants are complex mixtures of different substances. For example, the antioxidant BNTI (CAS number 184378-08-3) is the benzenamine and N -phenyl reaction products with 2,4,4-trimethylpentene and isobutylene, while another antioxidant (BNST, CAS number 68921-45-9) is the benzenamine and N -phenyl reaction products with styrene and 2,4,4-trimethylpentene. , These antioxidants are technical mixtures that, at minimum, contain monobutyl-, dibutyl-, monooctyl-, dioctyl-, dioctyl-monostyrenated, and monooctyl-monostyrenated substitutes on the benzene ring of DPA. Moreover, the structures of many antioxidants utilized on the global chemical market are largely unknown; manufacturers often keep such information confidential.…”

Distribution and Fate of Ultraviolet Absorbents and Industrial Antioxidants in the St. Lawrence River, Quebec, Canada

“…A nontarget study also revealed that Ar-SAs were the main group of contaminants detected in the muscle, gonads, and eggs of European eel ( Anguilla anguilla ), with concentrations in the order of μg/g (wet weight, ww). 29 …”

“…A nontarget study also revealed that Ar-SAs were the main group of contaminants detected in the muscle, gonads, and eggs of European eel (Anguilla anguilla), with concentrations in the order of μg/g (wet weight, ww). 29 The ecological risks of these contaminants are not certain, but there is some evidence showing their adverse effects on organisms. As summarized in the literature, 4,30 benzophenonetype UVFs may lead to endocrine-disrupting effects in vitro and in vivo (e.g., rats and fish), while SPAs and their transformation products may be related to hepatic toxicity, endocrinedisrupting effects (e.g., in fish), and carcinogenicity (e.g., in mice).…”

“…Wastewater treatment plant (WWTP) also releases these contaminants to the aquatic environment, ,− and many of these contaminants do not significantly degrade during treatment processes; therefore, sludge and effluent become a route of contamination for UVAs and IAs to the environment. , These contaminants have been detected in environmental matrices such as WWTP influent, effluent, and sewage sludge in China and Canada, − dust (indoor and playground) in Asian countries and the United States, − river sediment in Canada and Germany, marine sediment in Europe and China, ,− fresh surface water in Canada, Germany, and China, ,, tap water in Spain, and biota samples in the Great Lakes of North America and the Pearl River Estuary of China ,, (a review of selected published results is presented in Table S2). A nontarget study also revealed that Ar-SAs were the main group of contaminants detected in the muscle, gonads, and eggs of European eel (Anguilla anguilla), with concentrations in the order of μg/g (wet weight, ww) …”