Determination of 21 pesticides in agricultural products by HPLC-photodiode array detection

摘要

A screening method using HPLC for the simultaneous determination of 21 pesticides (including diflubenzuron, etofenprox, bentazone and chlorimuron) in agricultural products was developed. The pesticides were extracted from samples with acetonitrile.The extract was cleaned up on a gel permeation column and a silica gel cartridge. The silica gel cartridge was eluted with 5 acetone-hexane (A/H), 35 A/H, 60 A/H, and 30 methanol-acetone, successively. The eluates were concentrated and analysed on ahigh performance liquid chromatograph equipped with a photodiode array detector using an Inertsil ODS-2 column (150X4.6 mm i.d.) with a gradient system of 0.003 mol/litre phosphoric acid-acetonitrile as the mobile phase at a flow rate of 1.0 ml/min. Therecoveries at the level of 0.4μg/g were 62-120, except for bentazone in banana and quinclorac in 5 crops tested. Detection limits were 0.005-0.02μg/g for the 21 pesticides.