采用在线凝胶渗透色谱串联气相色谱-质谱(GPC/GC-MS),在选择离子模式(SIM)下建立了粮谷和油料作物中29种农药残留的分析方法.样品用乙腈溶液提取,经无水Na2SO4和N-丙基乙二胺(PSA)吸附剂净化后,直接进行GPC/GC-MS分析,外标法定量.29种农药在0.25～600 μg·L-1范围内具有较好的线性关系,相关系数均大于0.99.29种农药在3个加标水平(MRL、2MRL、4MRL)下的回收率为65％ ～ 148％；其中狄氏剂、对硫磷和甲胺磷等11种农药的LOQ(S/N≥10)为2.0～6.0 μg·kg-1,敌敌畏、乐果和六六六等18种农药的LOQ均小于1.0 μg·kg-1.该方法样品前处理简单、分析时间短、灵敏、可靠,适用于粮谷和油料作物中多种农药残留的检测.%A based on automated online gel permeation chromatography coupled with gas chromatography - mass spectrometry (GPC - GC/MS) method was developed for the rapid determination of 29 pesticide residues in cereals and oil crops. Pesticides were extracted from cereals and oil crops samples with acetonitrile and decontaminated via primary secondary amine ( PSA) sorbents, then determined by GPC/GC - MS. The identification and detection of target compounds were achieved in electron impact(EI) mode under selected ion monitoring (SIM) mode. The calibration curves of 29 pesticide residues were linear in the range of 0. 25 - 600 μg·L-1 with good correlation coefficients more than 0. 99. The recoveries for all compounds in feeds at three fortified levels of 1MRL, 2MRL and 4MRL were in the range of 65% - 148% . The limits of quantitation( LOQs, S/N = 10) for 11 pesti-cides(e. g. dieldrin, parathion - ethyl and methamidophos, etc. ) were in the range of 2. 0 - 6. 0 (μg · kg-1 and those of the other 18 pesticides (such as dichlorvos, dimethoate and HCH, etc. ) were less than 1.0 μg · kg-1. The method was simple, rapid and reliable, and could meet the require-ment for the simultaneous determination and analysis of 29 pesticide residues in cereals and oil crops.
展开▼
