采用气相色谱-质谱法测定果蔬中36种农药残留.果蔬试样经丙酮-水匀质,二氯甲烷液-液萃取,然后过石墨化炭黑固相萃取柱净化,浓缩定容后在DB-5毛细管色谱柱(30 m×0.25 mm,0.25 μm)分离,质谱中选择电喷雾离子源-选择离子监测模式.36种农药残留的质量浓度在一定范围内与其峰面积呈线性关系,检出限(3S/N)均不高于15 μg·kg-1.加标回收率在75.3%~115%之间,测定值的相对标准偏差(n=6)在0.6%~7.8%之间.

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%.