title: Enantioseparation and determination of the chiral phenylpyrazole insecticide ethiprole in agricultural and environmental samples and its enantioselective degradation in soil.
abstract: An effective method for the enantioselective determination of ethiprole enantiomers in agricultural and environmental samples was developed. The effects of solvent extraction, mobile phase and thermodynamic parameters for chiral recognition were fully investigated. Complete enantioseparation of the ethiprole enantiomers was achieved on a Lux Cellulose-2 column. The stereochemical structures of ethiprole enantiomers were also determined, and (R)-(+)-ethiprole was first eluted. The average recoveries were 82.7-104.9% with intra-day RSD of 1.7-8.2% in soil, cucumber, spinach, tomato, apple and peach under optimal conditions. Good linearity (R(2)≥0.9991) was obtained for all the matrix calibration curves within a range of 0.1 to 10 mg L(-1). The limits of detection for both enantiomers were estimated to be 0.008 mg kg(-1) in soil, cucumber, spinach and tomato and 0.012 mg kg(-1) in apple and peach, which were lower than the maximum residue levels established in Japan. The results indicate that the proposed method is convenient and reliable for the enantioselective detection of ethiprole in agricultural and environmental samples. The behavior of ethiprole in soil was studied under field conditions and the enantioselective degradation was observed with enantiomer fraction values varying from 0.494 to 0.884 during the experiment. The (R)-(+)-ethiprole (t1/2=11.6 d) degraded faster than (S)-(-)-ethiprole (t1/2=34.7 d). This report is the first describe a chiral analytical method and enantioselective behavior of ethiprole, and these results should be extremely useful for the risk evaluation of ethiprole in food and environmental safety.
authors.affiliation: Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing 210095, PR China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing 210095, PR China.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Shi
authors.affiliation: Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing 210095, PR China.
authors.forename: Beibei
authors.initials: B
authors.lastname: Gao
authors.affiliation: Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing 210095, PR China.
authors.forename: Mingming
authors.initials: M
authors.lastname: Tian
authors.affiliation: Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing 210095, PR China.
authors.forename: Xiude
authors.initials: X
authors.lastname: Hua
authors.affiliation: Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing 210095, PR China. Electronic address: wangmha@njau.edu.cn.
authors.forename: Minghua
authors.initials: M
authors.lastname: Wang
mesh_terms: D000383:Agriculture; D018553:Cucumis sativus / Q000737:chemistry; D004784:Environmental Monitoring; D005659:Fungicides, Industrial / Q000032:analysis*; D007564:Japan; D057230:Limit of Detection; D018551:Solanum lycopersicum / Q000737:chemistry; D027845:Malus / Q000737:chemistry; D011720:Pyrazoles / Q000032:analysis*; D012987:Soil / Q000737:chemistry; D012989:Soil Pollutants / Q000032:analysis*; D013237:Stereoisomerism
chemical_list: D005659:Fungicides, Industrial; D011720:Pyrazoles; D012987:Soil; D012989:Soil Pollutants; C472185:ethiprole
keywords: Absolute configuration; Chiral recognition mechanism; Enantioselective degradation; Enantioselective determination; Ethiprole