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Enantioselective toxicity and degradation of the chiral insecticide fipronil in Scenedesmus obliguus suspension system
Author(s) -
Qu Han,
Ma Ruixue,
Liu Donghui,
Wang Peng,
Huang Ledan,
Qiu Xingxu,
Zhou Zhiqiang
Publication year - 2014
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.2702
Subject(s) - fipronil , enantioselective synthesis , toxicity , enantiomer , chemistry , scenedesmus , chlorophyll , environmental chemistry , food science , chromatography , algae , botany , pesticide , biology , stereochemistry , organic chemistry , ecology , catalysis
Fipronil is an effective insecticide, but it presents highly toxic effects in nontarget aquatic organisms. The present study examined the enantioselective toxicity and degradation of fipronil enantiomers in a freshwater algae Scenedesmus obliguus suspension. There was a substantial difference in the acute toxicity of the enantiomers to S. obliguus , with 72‐h median effective concentrations (EC50s) of 0.29 mg L −1 and 1.50 mg L −1 for the R‐fipronil and S‐fipronil, respectively. The influences on the concentration of chlorophyll a , chlorophyll b , and carotenoids were determined, and the effects of fipronil on the concentration of chlorophyll a and chlorophyll b were also enantioselective. The degradation of fipronil in algae suspension was enantioselective, with half‐lives for R‐fipronil and S‐fipronil of 2.9 d and 3.2 d, respectively, and the enantiomer fraction reaching 0.65 at the day 17. The enantiomeric differences should be taken into consideration for fipronil risk assessment. Environ Toxicol Chem 2014;33:2516–2521 . © 2014 SETAC