Determination of 36 Pesticide Residues in Fruits and Vegetables by SPE-GC-MS

A method of GC-MS combined with solid-phase extraction (SPE) was used for the determination of 36 pesticide residues in fruits and vegetables. Samples were homogenized and extracted by the mixture of acetone and water,and then extracted again with dichloromethane. The extracted solution was purified on a graphitic carbon SPE column and separated on a DB-5 capillary column (30 m×0.25 mm,0.25 μm). EI-SIM was adopted in MS. The linear relationship between the peak area and mass concentration of the 36 pesticide residues was in a certain range,with detection limits no more than 15 μg·kg-1. The recovery rates measured by standard addition method were in the range of 75.3%-115%,with RSD in the range of 0.6%-7.8%.