title: Enantioselective determination of the insecticide indoxacarb in cucumber and tomato by chiral liquid chromatography-tandem mass spectrometry.
abstract: A convenient and precise chiral method was developed and validated for measuring indoxacarb enantiomers in cucumber and tomato using liquid chromatography-tandem mass spectrometry (LC-MS/MS) with a reversed-phase Chiralpak AD-RH column. The target analytes were extracted by acetonitrile and then purified by solid phase extraction (SPE) using NH2 /Carb combined-cartridge. Parameters including the matrix effect, linearity, precision, accuracy, and stability were used. Then the proposed method was successfully applied to investigate the possible enantioselective degradation of rac-indoxacarb in cucumber and tomato under open conditions. The results indicated that the degradation of indoxacarb enantiomers followed first-order kinetics in cucumber and tomato. The half-lives of (+)-S-indoxacarb in cucumber and tomato were 3.0 and 5.9 days, respectively; while the (-)-R-indoxacarb were 7.3 and 12.2 days, respectively. The data of the half-lives showed that (+)-S-indoxacarb was preferentially degraded in cucumber and tomato. Moreover, indoxacarb degraded faster in cucumber than in tomato.
authors.affiliation: Institute of Plant Protection, Chinese Academy of Agricultural Sciences, State Key Laboratory for Biology of Plant Diseases and Insect Pests, Beijing, PR China.
authors.forename: Huanqing
authors.initials: H
authors.lastname: Wang
authors.forename: Fengshou
authors.initials: F
authors.lastname: Dong
authors.forename: Yuanbo
authors.initials: Y
authors.lastname: Li
authors.forename: Xiu
authors.initials: X
authors.lastname: Chen
authors.forename: Youpu
authors.initials: Y
authors.lastname: Cheng
authors.forename: Wensheng
authors.initials: W
authors.lastname: Xiang
authors.forename: Yongquan
authors.initials: Y
authors.lastname: Zheng
mesh_terms: D000097:Acetonitriles / Q000737:chemistry; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D028462:Cucumis / Q000737:chemistry*; D007306:Insecticides / Q000032:analysis*; D018551:Solanum lycopersicum / Q000737:chemistry*; D013058:Mass Spectrometry; D015394:Molecular Structure; D010078:Oxazines / Q000032:analysis*; D013237:Stereoisomerism
chemical_list: D000097:Acetonitriles; D007306:Insecticides; D010078:Oxazines; C401104:indoxacarb; C032159:acetonitrile