气相色谱-串联质谱法(GC-MS/MS)测定大米中25种农药及其代谢物残留

Determination of 25 Pesticide and Metabolites Residues in Rice by Gas Chromatography-Tandem Mass Spectrometry

建立气相色谱-串联质谱法同时测定大米中25种农药及其代谢物残留的方法。样品经粉碎后,用乙腈-水-乙酸溶液(70∶29∶1)提取,提取液经无水硫酸镁和氯化钠盐析,再采用无水硫酸镁、PSA和C18净化后,直接进行气相色谱-串联质谱(GC-MS/MS)分析,采用保护剂基质内标法进行定量。结果表明,待测物质在2.5~100μg/L范围内线性关系良好,相关系数(R^(2))均大于0.995,定量限为0.01 mg/kg,样品平均加标回收率为67.2%~111.3%,相对标准偏差为0.2%~18.2%,满足方法学要求。该方法简单、快速、准确、经济,适用于大批量大米样品中农药筛查和定量检测。

In the present study, a multiresidue method was established for the analysis of 25 pesticides and metabolites in rice by using gas chromatography-tandem mass spectrometry(GC-MS/MS). After the rice samples were crushed rice samples, they were initially extracted with acetonitrile/water/acetic acid with a ratio of 70∶29∶1. The extracting solution was salted out with anhydrous magnesium sulfate and sodium chloride, and then cleaned up by anhydrous magnesium sulfate, PSA and C18, finally analyzed by GC-MS/MS. The internal standard method of protectant matrix was used for quantitative analysis. The result indicated a good linearity(R^(2)>0.995) within the range of 2.5~100 μg/L,the average recoveries and RSD of four different spiked level(0.01 mg/kg~0.2 mg/kg) were 67.2%~111.3% and 0.2%~18.2%, respectively. The limit of quantification of the method was 0.01 mg/kg. The method was simple, fast, accurate and economical, and was suitable for the qualitative and quantitative detection of pesticide and metabolites residues in rice.