Diastereoisomer- and Enantiomer-Specific Accumulation, Depuration, and Bioisomerization of Hexabromocyclododecanes in Zebrafish (Danio rerio)

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• 作者：Miaomiao Du ; Lifeng Lin ; Changzhou Yan ; Xian Zhang
• 刊名：Environmental Science & Technology (ES&T)
• 出版年：2012
• 出版时间：October 16, 2012
• 年：2012
• 卷：46
• 期：20
• 页码：11040-11046
• 全文大小：311K
• 年卷期：v.46,no.20(October 16, 2012)
• ISSN：1520-5851

文摘

In this study, zebrafish (Danio rerio) were exposed to two dietary concentrations of individual HBCD diastereoisomers (伪-, 尾-, and 纬-HBCD) for 42 days, followed by clean food for 21 days, to examine bioaccumulation, depuration, and enantiomer fractions (EFs) of HBCD diastereoisomers and to test the bioisomerization of HBCDs in fish. The depuration of 伪-, 尾-, and 纬-HBCD in zebrafish followed the first-order process. Bioaccumulation parameters of the three diastereoisomers differed between low and high dose, suggesting that the bioaccumulation of them is concentration dependent. Calculated assimilation efficiencies (AEs), biomagnification factors (BMFs), and half-lives (t_1/2) of 伪-HBCD were the highest among the three diastereoisomers. Furthermore, the study showed that zebrafish could biotransform 纬-HBCD to 伪-HBCD. The highest AE, BMF, and t_1/2 of 伪-HBCD and bioisomerization of 纬-HBCD to 伪-HBCD could explain why 伪-HBCD appears to be dominant in biota samples. The EFs for 伪- and 纬-HBCD in zebrafish estimated at different times of bioaccumulation and depuration were all significantly greater than those in corresponding food (P < 0.05), indicating selective enrichment of (+) 伪-enantiomer and (+) 纬-enantiomer relative to (鈭? 伪-enantiomer and (鈭? 纬-enantiomer, respectively.