title: Enantiomer-specific accumulation, depuration, metabolization and isomerization of hexabromocyclododecane (HBCD) diastereomers in mirror carp from water.
abstract: Until now, the bioaccumulation of hexabromocyclododecanes (HBCDs) in aquatic organisms has been studied only via dietary exposure. To better understand the environmental fate of HBCDs, we conducted a bioaccumulation test by exposing mirror carp to three HBCD diastereomers in water during 30d of accumulation and 30d of depuration according to Organization for Economic Co-operation and Development (OECD) Test Guidelines 305 (Bioaccumulation in Fish: Aqueous and Dietary Exposure). We found that the BCFKL values (bioconcentration factor calculated from kinetic data and adjusted to lipid content) of α-HBCD in different tissues of the carp were in the range of (3.07-4.52)×10(4), much higher than those of β-HBCDs (1.03-1.90×10(3)) and γ-HBCD (0.95-1.73×10(3)), as was true of t1/2. The order of BCFK for α-, β- and γ-HBCD in different tissues was viscera>gill>skin>muscle. β-HBCD and γ-HBCD were transformed to α-HBCD, with 50.0-92.9% and 96.2-98.6% bioisomerization efficiencies by the end of the experiment, respectively. No isomerization product from α-HBCD was found. Selective enrichment of the (+) α- and γ-HBCD was found, whereas β-HBCD did not show significant enantioselectivity. New metabolites such as tetrabromocyclododecene (TBCDe), tribromocyclododecadiene (TriBCDi) and tribromocyclododecatriene (TriBCDie) were found in mirror carp for the first time under multiple reaction monitoring (MRM) mode.
authors.affiliation: MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
authors.forename: Yanwei
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China. Electronic address: sunhongwen@nankai.edu.cn.
authors.forename: Hongwen
authors.initials: H
authors.lastname: Sun
authors.affiliation: MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
authors.forename: Yuefei
authors.initials: Y
authors.lastname: Ruan
mesh_terms: D000818:Animals; D002347:Carps / Q000378:metabolism*; D006842:Hydrocarbons, Brominated / Q000378:metabolism*; D013237:Stereoisomerism; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D006842:Hydrocarbons, Brominated; D014874:Water Pollutants, Chemical; C089796:hexabromocyclododecane
keywords: Bioaccumulation; Bioisomerization; Enantioselectivity; HBCDs; Metabolites