title: Enantioselective toxicokinetics study of the bioaccumulation and elimination of α-hexachlorocyclohexane in loaches (Misgurnus anguillicaudatus) and its environmental implications.
abstract: The enantioselective bioaccumulation and elimination of α-hexachlorocyclohexane (α-HCH) in loaches (Misgurnus anguillicaudatus) were studied for the first time. Valid chiral residue analysis methods for α-HCH enantiomers in water and loach samples were established using gas chromatography coupled with electron capture detector and a BGB-172 chiral column. A rapid accumulation process was found during the 39-d bioaccumulation experiment. The α-HCH in loaches reached its maximum on the fourth day, after which it fluctuated slightly, reflecting a balance between elimination and reuptake. The maximum bioaccumulation factor was 728 at the 10 μg L(-1) exposure level. The enantiomeric fraction (EF) values showed that the bioaccumulation was enantioselective with enantioenrichment of (+)-α-HCH in the loaches. The elimination experiment indicated that the degradation kinetics of α-HCH fitted a typical first-order kinetics model, and the half-life was about 5 d. Significant enantioselectivity was observed during the elimination process, with the EFs declining from higher than 0.5-0.39, suggesting (+)-α-HCH is preferentially biotransformed than (-)-α-HCH in loaches. The results reveal a high capacity for α-HCH bioconcentration by loaches and that biotransformation is the main route of decontamination.
authors.affiliation: Department of Applied Chemistry, China Agricultural University, Beijing 100193, PR China.
authors.forename: Rui-xue
authors.initials: RX
authors.lastname: Ma
authors.forename: Dong-hui
authors.initials: DH
authors.lastname: Liu
authors.forename: Han
authors.initials: H
authors.lastname: Qu
authors.forename: Gao-xin
authors.initials: GX
authors.lastname: Zhou
authors.forename: Zhi-qiang
authors.initials: ZQ
authors.lastname: Zhou
authors.forename: Peng
authors.initials: P
authors.lastname: Wang
mesh_terms: D000818:Animals; D001711:Biotransformation; D003531:Cypriniformes / Q000378:metabolism*; D004784:Environmental Monitoring; D006207:Half-Life; D001556:Hexachlorocyclohexane / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*
chemical_list: D014874:Water Pollutants, Chemical; C040534:alpha-hexachlorocyclohexane; D001556:Hexachlorocyclohexane