title: The toxicity, bioaccumulation, elimination, conversion of the enantiomers of fipronil in Anodonta woodiana.
abstract: The enantioselective bioaccumulation and elimination of fipronil in Anodonta woodiana (A. woodiana) were studied and the main metabolites fipronil desulfinyl, fipronil sulfide and fipronil sulfone were determined. The acute toxicity of the enantiomers of fipronil and the three metabolites were also investigated. In the bioaccumulation process, fipronil in A. woodiana reached equilibrium after 11days with BCF value of 0.2, and the enantiomeric fraction (EF) values showed that the bioaccumulation was enantioselective with enantioenrichment of S-fipronil. The degradation of fipronil in A. woodiana fitted first-order kinetics model with half-lives of the enantiomers were 5.8 d for R-fipronil and 7.6 d for S-fipronil, and the EF values decreasing from 0.5 gradually indicating the R-enantiomer was preferentially degraded. The degradation of single enantiomers was also performed and the results revealed a fast conversion of R-fipronil to S-fipronil by A. woodiana. The three metabolites were all detected in A. woodiana-water system, in which fipronil sulfone and fipronil sulfide had higher concentration levels. According to the 72-h LC50 values, S-fipronil was much more toxic than the racemate and R-fipronil. Moreover, the metabolites were more toxic than the parent fipronil. The results suggested the individual enantiomers of chiral pollutants and the metabolites should be considered in the risk assessments.
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, Department of Applied Chemistry, China Agricultural University, Beijing 100193, PR China.
authors.forename: Han
authors.initials: H
authors.lastname: Qu
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, Department of Applied Chemistry, China Agricultural University, Beijing 100193, PR China.
authors.forename: Rui-Xue
authors.initials: RX
authors.lastname: Ma
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, Department of Applied Chemistry, China Agricultural University, Beijing 100193, PR China.
authors.forename: Dong-Hui
authors.initials: DH
authors.lastname: Liu
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, Department of Applied Chemistry, China Agricultural University, Beijing 100193, PR China.
authors.forename: Xu
authors.initials: X
authors.lastname: Jing
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, Department of Applied Chemistry, China Agricultural University, Beijing 100193, PR China.
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, Department of Applied Chemistry, China Agricultural University, Beijing 100193, PR China.
authors.forename: Zhi-Qiang
authors.initials: ZQ
authors.lastname: Zhou
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, Department of Applied Chemistry, China Agricultural University, Beijing 100193, PR China. Electronic address: wangpeng@cau.edu.cn.
authors.forename: Peng
authors.initials: P
authors.lastname: Wang
mesh_terms: D000818:Animals; D049877:Anodonta / Q000378:metabolism*; D007306:Insecticides / Q000378:metabolism*; D007700:Kinetics; D011720:Pyrazoles / Q000378:metabolism*; D013237:Stereoisomerism; D013440:Sulfides / Q000378:metabolism; D013450:Sulfones / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D007306:Insecticides; D011720:Pyrazoles; D013440:Sulfides; D013450:Sulfones; D014874:Water Pollutants, Chemical; C082360:fipronil
keywords: Anodonta woodiana; Chiral conversion; Fipronil; Metabolites; Toxicity