GC-MS/MS Determination of Residual Amounts of 5 Pesticides in Leafy Vegetables Growing Soil with Accelerated Solvent Extraction

Sample of leafy vegetables growing soil obtained after sieving (180 μm) was added with anhydrous sodium sulfate and diatomite to grind. The sample obtained by the above procedure was extracted with the mixture of acetone and n-hexane (volume ratio of 2∶3) used as extraction solvent for accelerated solvent extraction. The extract was evaporated to near dryness by N₂-blowing. After purification, GC-MS/MS was applied to the determination of residual amounts of 5 pesticides, i.e. acetamiprid, indoxacarb, chlorantraniliprole, phoxim and iprodione in purified liquid. The HP-5MS chromatographic column was used for GC separation and the multiple reaction monitoring mode was adopted in MS/MS determination. Linear relationships between values of peak area and mass concentration of the 5 pesticides were kept in the same range of 0.05-5.0 mg·L^-1, with detection limits (3S/N) in the range of 0.010-0.018 μg·kg^-1. On the base of blank soil sample, test for recovery was made by standard addition method; values of recovery found were in the range of 76.9%-100%, with RSDs (n=6) of determined values in the range of 1.5%-4.1%.