百合中乐果等3种农药残留的气相色谱-串联质谱法一测多评研究

Study on QAMS of Three Pesticide Residues Such as Dimethoate in Lilii Bulbus by GC-MS/MS

目的建立气相色谱-串联质谱(GC-MS/MS)测定百合中乐果等3种农药残留的一测多评方法。方法样品经乙腈提取、Cleanert TPH柱净化、GC-MS/MS测定,根据色谱峰相对保留时间和质荷比信息进行定性分析,以乐果二级离子扫描峰(125/79)面积为参照,计算其与敌敌畏二级离子扫描峰(185/93)面积和毒死蜱二级离子扫描峰(313. 9/257. 9)面积之间的相对校正因子,建立以乐果为对照品,测定百合中乐果等3种农药残留量的GC-MS/MS法。结果敌敌畏、乐果、毒死蜱进样量均在0. 1～1. 0 ng范围内与其色谱峰面积均有较好的线性关系,检出限(以进样量计)敌敌畏为1. 84×10^(-4) ng,乐果为2. 87×10^(-2) ng,毒死蜱为1. 75×10^(-4) ng;平均回收率敌敌畏为95. 46%,乐果为96. 21%,毒死蜱为96. 01%,RSD分别为0. 99%,0. 92%,0. 74%(n=9)。结论该一测多评方法定量准确、简单、快速,适用于百合中敌敌畏、乐果、毒死蜱农药残留的定量分析。

Objective To establish a quantitative analysis of multi-components by single marker（QAMS） method for the simultaneous determination of three pesticide residues such as dimethoate in Lilii Bulbus by GC- MS/MS. Methods The samples were extracted by acetonitrile, purified by Cleanert TPH column and determined by GC- MS/MS. Information on relative retention time and mass charge ratio was used for qualitative analysis, the peak area obtained by secondary ion MS of dimethoate（125/79） was taken as the reference peak to calculate the relative correction factors for the peak area of dichlorvos（185/93） and chlorpyrifos（313. 9/257. 9）, to establish a GC- MS/MS method for determination of three pesticide residues such as dimethoate in Lilii Bulbus with dimethoate as the reference substance. Results There was a good linear correlation in the range of 0. 1 - 1.0 ng for dichlorvos, dimethoate and chlorwrifos. Limit of quantification（calculated in sample size） of dichlo^os, dimethoate and chlorpyrifos were 1.84 x 10 4 ng, 2. 87 x 10 2 ng, 1.75 x 10 4 ng, respectively. The average recovery rates of dichlorvos, dimethoate and chlorpyrifos were 95.46%, 96.21% and 96.01%, respectively, and RSDs were 0.99%, 0.92% and 0.74% （n = 9）. Conclusion The QAMS method is accurate, simple and rapid, which is suitable for the quantitative analysis of residual quantity of dichlorvos, dimethoate and chlorwrifos residues in Lilii Bulbus.