Environmental behavior of benalaxyl and furalaxyl enantiomers in agricultural soils |
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Authors: | Fang Qin Yong X. Gao Bao Y. Guo Peng Xu Jian Z. Li |
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Affiliation: | 1. Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China;2. Department of Environmental Engineering, North China Institute of Science and Technology, Yanjiao, Beijing, China |
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Abstract: | The enantioselective environmental behavior of the chiral fungicides benalaxy and furalaxyl in agricultural soils in China was studied. Although sorption onto soils was non-enantioselective, the leaching of benalaxy and furalaxyl was enantioselective in soil columns. The concentrations of the S-enantiomers of both fungicides in the leachates were higher than the R-enantiomers. This can be attributed to enantioselective degradation of the two fungicides in the soil column. Enantioselective degradation of the two fungicides was verified by soil dissipation experiments, and the R-enantiomers degraded faster than the S-enantiomers in partial soils. The half-life was 27.7–57.8 days for S-benalaxyl, 20.4–53.3 days for R-benalaxyl, 19.3–49.5 days for S-furalaxyl and 11.4–34.7 days for R-furalaxyl. The degradation process of the two fungicide enantiomers followed the first-order kinetics (R2 > 0.96). Compared to furalaxyl, benalaxyl degraded more slowly and degradation was less enantioselective. These results are attributed to the influence of soil physicochemical properties, soil microorganisms, and environmental factors. |
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Keywords: | Chiral fungicides enantioselective environmental behavior benalaxyl furalaxyl |
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