title: Environmental behavior of benalaxyl and furalaxyl enantiomers in agricultural soils.
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 (R(2) > 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.
authors: a Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing , China.
authors: Fang
authors: F
authors: Qin
authors: Yong X
authors: YX
authors: Gao
authors: Bao Y
authors: BY
authors: Guo
authors: Peng
authors: P
authors: Xu
authors: Jian Z
authors: JZ
authors: Li
authors: Hui L
authors: HL
authors: Wang
mesh_terms: D065966:Absorption, Physicochemical; D000327:Adsorption; D000383:Agriculture; D000409:Alanine / Q000031:analogs & derivatives* / Q000737:chemistry; D001673:Biodegradation, Environmental; D002681:China; D005659:Fungicides, Industrial / Q000737:chemistry*; D005663:Furans / Q000737:chemistry*; D006207:Half-Life; D007700:Kinetics; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D005659:Fungicides, Industrial; D005663:Furans; D012987:Soil; D012989:Soil Pollutants; C052866:benalaxyl; C490004:furalaxyl; D000409:Alanine
keywords: Chiral fungicides; benalaxyl; enantioselective environmental behavior; furalaxyl