采用乙酸乙酯匀浆提取残留在蔬菜中的农药,过凝胶渗透色谱净化柱,用环己烷-乙酸乙酯(体积比1∶1)淋洗液以5 mL·min-1的流量洗脱凝胶柱,经淋洗收集并浓缩第85~175 mL流分,用氮磷检测器对蔬菜中23种农药残留同时进行检测.采用三阶程序升温,23种杀虫剂在HP-5毛细管柱上得到较好分离,回收率在75.6%~110.7%之间,相对标准偏差在0.56%~8.26%之间,方法检出限为0.002~0.005 mg·kg-1,在0.5~5.0 mg·L-1范围内呈线性.方法适用于蔬菜、水果等植物性食品中农药残留的分析.

Residual pesticides in vegetables were extracted with ethyl acetate and purified by passing the extract through a gel permeation chromatographic column.Elute the column with cyclohexane-ethyl acetate (1∶1,V/V) at a flow rate of 5 mL·min-1 and collect the fractions between 85-175 mL.Concentrate the collected eluate to dryness and dissolve it with 1 mL of cyclohexane-ethyl acetate.The residual pesticides were detected with a capillary gas chromatograph equipped with nitrogen-phosphorus detector.Using the established three steps-heating program,23 peaks of pesticides were resolved.Detection limits of the proposed method were in the range of 0.002-0.005 mg·kg-1,and linearity relationship between 0.5-5.0 mg·L-1 was obtained.Recovery was ranged in 75.6%-110.7% and RSDs of determination were ranged in 0.56%-8.26%.The method has been applied to the analysis of the residual pesticides in vegetables and fruits.