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Photochemical fate of medetomidine in coastal and marine environments.
Cai, Yi; Apell, Jennifer N; Pflug, Nicholas C; McNeill, Kristopher; Bollmann, Ulla E.
  • Cai Y; Department of Environmental Science, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark.
  • Apell JN; Institute for Biogeochemistry and Pollutant Dynamics, ETH Zurich, Universitaetstrasse 16, 8092 Zurich, Switzerland; Department of Civil and Urban Engineering, New York University Tandon School of Engineering, 6 Metrotech Center, Brooklyn, New York, 11201, USA.
  • Pflug NC; Institute for Biogeochemistry and Pollutant Dynamics, ETH Zurich, Universitaetstrasse 16, 8092 Zurich, Switzerland.
  • McNeill K; Institute for Biogeochemistry and Pollutant Dynamics, ETH Zurich, Universitaetstrasse 16, 8092 Zurich, Switzerland.
  • Bollmann UE; Department of Environmental Science, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark; Geological Survey of Denmark and Greenland (GEUS), ØsterVoldgade 10, 1350 Copenhagen, Denmark. Electronic address: ueb@geus.dk.
Water Res ; 191: 116791, 2021 Mar 01.
Article en En | MEDLINE | ID: mdl-33433334
ABSTRACT
Medetomidine has been authorized in ship hull paints as an antifouling biocide under the biocidal product regulation in Europe since 2016. Its release into marine systems causes concerns over persistence and toxicity. However, the environmental fate of medetomidine has not been fully investigated. In this study, the photodegradation of medetomidine under natural sunlight conditions was investigated using collected coastal and sea waters. In addition, the phototransformation of medetomidine with reactive species (i.e., singlet oxygen, excited triplet state organic matter, and hydroxyl radicals) under UVA light was examined. Photoproducts were isolated by high-performance liquid chromatography (HPLC), identified by a combination of nuclear magnetic resonance (NMR) spectroscopy and time-of-flight mass spectrometry (qTOF), and reaction mechanisms were proposed. The results show that medetomidine is a neutral base (pKa of protonated form = 7.2) that leads to two different protonation states in the aquatic environment. Photodegradation of neutral medetomidine was dominated by reaction with singlet oxygen, while protonated medetomidine was relatively photostable. The contribution of reactive species to the overall photodegradation of neutral medetomidine was calculated to provide an assessment of phototransformation of medetomidine. The half-live of medetomidine was < 1.5 days in natural waters (pHcoastal = 8.3; pHsea = 8.1) under sunlit near-surface conditions, suggesting that it is not persistent in the aquatic environment. Because medetomidine has a relatively short half-life in sunlit aquatic ecosystems, a number of products, such as 2-(2,3-dimethylphenyl)propanamide, can be formed by photochemical reactions of medetomidine, with unknown consequences for marine and coastal waters.
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Texto completo: 1 Banco de datos: MEDLINE Asunto principal: Contaminantes Químicos del Agua / Medetomidina País como asunto: Europa Idioma: En Año: 2021 Tipo del documento: Article

Texto completo: 1 Banco de datos: MEDLINE Asunto principal: Contaminantes Químicos del Agua / Medetomidina País como asunto: Europa Idioma: En Año: 2021 Tipo del documento: Article