Stereoselective Determination of a Novel Chiral Insecticide, Sulfoxaflor, in Brown Rice, Cucumber and Apple by Normal-Phase High-Performance Liquid Chromatography

摘要

An effective high-performance liquid chromatography method was developed for the stereoselective determination of a new sulfoximines insecticide, sulfoxaflor, in brown rice, cucumber and apple. Target compounds were extracted with acetonitrile and an aliquot cleaned with Cleanert PestiCarb/PSA (primary and secondary amine) cartridge. Five polysaccharide-based columns were investigated on the separation of sulfoxaflor stereoisomers and the best was achieved on a ChromegaChiral CCA column with n-hexane/ethanol/ methanol (90:2:8, v/v/v) as mobile phase by UV detection at 220 nm at 20oC. The resolutions of the four stereoisomers were 1.85, 1.54 and 3.08, and the elution order was identified by optical rotation and stereoisomers ratio. The mean recoveries of sulfoxaflor stereoisomers ranged from 77.1% to 99.3%, with relative standard deviations less than 8.9% at three concentration levels in all matrices. The limits of detection for all stereoisomers varied from 0.05 mg/kg to 0.07 mg/kg, while the limit of quantification did not exceed 0.22 mg/kg. The method was then successfully applied to determine the sulfoxaflor stereoisomers in authentic samples, confirming that it is convenient and reliable for stereoselective determination of sulfoxaflor stereoisomers in food. Chirality 26:114-120, 2014.