HPLC Simultaneous Determination of Residual Amounts of Pesticides in Fruits and Vegetables with Solid Phase Extraction

A method of HPLC for simultaneous determination of 9 kinds of pesticides in fruit and vegetable samples was proposed.The samples were extracted with acetonitrile,and residual pesticides in sample solution were separated and enriched by solid phase extraction(SPE) on Florisil column.The SPE column was eluted with a mixture of n-hexane and dichloromethane(40+60),and the eluate obtained was evaporated to dryness by N2-blowing at 40 ℃ and taken up with 1.0 mL of CH3OH.A aliquot of 1.0 μL was used for HPLC determination.C18 column was used as the stationary phase and a mixture of methanol and water was used as the mobile phase.UV detection at 254 nm was adopted.Linear relationships were found in the same range of 0.01-1.0 mg·L-1 for the 9 pesticides,with values of detection limit(3S/N) in the range of 0.009-0.049 mg·kg-1.On the base of samples of fruit and vegetable,test for recovery were made by standard adiition method.Values of recovery and RSD′s(n=6) found were in the ranges of 68.3%-103.2% and 1.8%-13.9%(for vegetables);69.4%-106.0% and 2.9%-11.8%(for fruits),respectively.