凝胶色谱净化-毛细管气相色谱法同时测定蔬菜中23种农药残留

Determination of 23 Residual Pesticides in Vegetables by Gel Permeation Chromatographic Purification and Capillary Gas Chromatography

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,用环已烷-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 eyelohexane-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 eyelohexane-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.