Determination of Five Organophosphorus Pesticides in Vegetables bySolid Phase Extraction-High Performance Liquid Chromatography

An analytical method was developed for the determination of five organophosphorus pesticides including methyl parathion, triazophos, ethyl parathion, fenthion and phoxim in vegetables by solid phase extraction (SPE) coupled to high performance liquid chromatography (HPLC). The SPE procedures were based on the home-made Florisil SPE columns. The experimental conditions for the sample preparation such as extraction solvent, the type of SPE column, SPE column stuffing and elution solvents and corresponding instrumental conditions for HPLC detection were optimized in detail. The linear range was from 0.02 to 2.00 μg/L. The detection limit ranged from 0.10 to 0.17 μg/g. The method was used for the determination of trace organophosphorus pesticides in spiked vegetables. The average recovery was from 76.5% to 109.0% and the RSD was from 2.1% to 8.0%. The results indicate that the method is very suitable for the rapid determination of trace organophosporus pesticides in vegetables.