凝胶渗透色谱-固相萃取净化气相色谱-质谱法检测甘草、黄芪、人参和银杏叶中24种农药残留

目的: 建立一种同时测定甘草、黄芪、人参和银杏叶中24种农药残留的分析方法。 方法: 样品以丙酮超声提取,并采用凝胶渗透色谱(GPC)和氨基-石墨炭固相萃取柱(NH₂-CARB)结合的方法进行净化,选用气相色谱与质谱串联技术(GC-MS)在DB-5MS毛细管柱上用程序升温技术分离,采用选择离子检测方式,以保留时间和特征离子进行目标成分的定性鉴别,以外标法对样品进行测定。 结果: 24种农药可在34 min内完全分离,除甲胺磷、敌敌畏外,3个水平添加回收率在70%~120%之间,RSD小于11%。(n=9)。该方法对多种农药的检测限为0.5~7.2 μg·kg^-1,定量限为1.2~24.0 μg·kg^-1,进样精密度在1.65%~3.00%之间。 结论: 本方法的灵敏度、准确度和精密度均符合农药多残留检测的技术要求,适用于甘草、黄芪、人参和银杏叶中多种农药残留的检测。

Objective: To establish an analytical method for the simultaneously determination of 24 pesticide residues in Glycyrrhiza uralensis,Astragalus mongholicus,Ginseng and Ginkgo leaf. Method: The sample was extracted with acetone,and the extract was cleaned using GPC and SPE,Concentrated using Nitrogen blow. Based on GC-MS the pesticides were separaed on a DB-5MS column using a temperature program and were detected with a mass selective detector in selective ion monitoring(SIM)mode.The target pesticides were identified by comparing their retention times and characteristic ions with reference. Result: 24 Pesticides were separated within 34 min.The average spiked recoveries in three levels were 70%-120% with relative standard deviations(RSD)below 11% besides methamidophos and dichlorvos(n=9). The limits of detection(LOD)were 0.5-7.2 μg·kg^-1. The limits of quantitation(LOQ)were 1.2-24 μg·kg^-1. Conclusion: The method is sensitive for the residue analysis of 24 pesticides in Glycyrrhiza uralensis,Astragalus mongholicus,Ginseng and Ginkgo leaf.