Multiresidue Analysis of 176 Pesticides and Metabolites in Pre-harvested Fruits and Vegetables for Ensuring Food Safety by Gas Chromatography and High PerformanceLiquid Chromatography

摘要

A broad-range, sensitive and reliable multiresidue analytical method is presented for identifying and inspecting 176 pesticide residues, including organophosphate, organochlorine, synthetic pyrethroid, organonitrogen and carbamate, in pre-harvested fruits and vegetables. Pesticide residues were extracted from samples with acetone, followed by liquid-liquid partition and solid-phase extraction. Seventy one and 83 pesticides were determined, respectively, by gas chromatography with a flame photometric detector and an electron capture detector. Nineteen carbamate pesticides and several metabolites were measured by high-performance liquid chromatography (HPLC) with a post-column derivation system and a fluorescence detector; and three additional pesticides, i.e., car-bendazim, thiabendazole, and imidacloprid, were detected by HPLC using an ultraviolet detector at 280 nm. The proposed method was validated for 14 fruits and 8 vegetables using samples spiked with pesticide standards (0.1- 5.0 mug/g) in triplicate. Good sensitivity and repeatability were obtained with detection limits of 0.001- 0.03 mug/g, and all limits of detection were lower than one-fifth of their specific maximum residue levels. The recovery rates for most pesticides in various fruits and vegetables were 60-120% with relative standard deviations < 20%. With more than 4,300 samples collected from the field examined to assess the performance, it is proposed that this method be applied for routine monitoring, legislation implementation and farmer education programs.