Bioaccumulation and Biotransformation of BDE‐47 Using Zebrafish Eleutheroembryos (Danio rerio)

Abstract

AbstractPolybrominated diphenyl ethers (PBDEs) are well‐known endocrine disrupting chemicals identified as organic persistent pollutants. Their metabolites OH‐BDE and MeO‐BDE have been reported to be potentially more toxic than the postulated precursor PBDEs. One of the most predominant congeners of PBDEs in the environment is BDE‐47, due to its high presence in industrially used mixtures. In the present study, the bioaccumulation and biotransformation of BDE‐47 into its major metabolites is evaluated using zebrafish (Danio rerio) eleutheroembryos adapting a previously developed alternative method to bioconcentration official guideline Organisation for Economic Co‐ordination and Development 305, which reduces the animal suffering, time, and cost. For the simultaneous determination of BDE‐47 and its metabolites in larvae and exposure medium, and considering the polarity difference of the analytes and the small sample size, the development of a validated analytical method is a step to ensure quality results. In the present study, an ultrasound‐assisted extraction followed by a solid phase extraction dispersive clean‐up step and gas chromatography‐mass spectrometry‐microelectron capture detector (GC‐MS‐μECD) with a previous derivatization process was optimized and validated. Bioconcentration factors (BCFs) were calculated using a first‐order one‐compartment toxicokinetic model. The profiles found show rapid absorption in the first hours of larval development and great bioaccumulative capacity, finding BCFs of 7294 ± 899 and 36 363 ± 5702 at nominal concentrations of 10 and 1 μg L−1, respectively. Metabolization studies show increasing concentrations of the metabolites BDE‐28, 2ʹ‐OH‐BDE‐28, and 5‐MeO‐BDE‐47 throughout the exposure time. The results obtained show the feasibility of the method for bioaccumulation and open up the possibility of metabolic studies with zebrafish eleutheroembryos, which is a very underdeveloped field without official testing or regulation. Environ Toxicol Chem 2023;42:835–845. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.