糙米中丁硫克百威及其代谢物的残留测定

目的]监测与评价糙米中丁硫克百威及其代谢物克百威、3-羟基克百威的残留量。方法]建立凝胶渗透色谱（GPC）净化、气相色谱-质谱（GC-MS）同时测定糙米中丁硫克百威及其代谢物克百威、3-羟基克百威残留的方法。样品中的待测农药组分采用环己烷-乙酸乙酯（1∶1,V/V）提取,GPC和中性氧化铝（A l2O3）小柱净化,GC-MS测定。结果]丁硫克百威和克百威的最低检测量均为2.0×10-11g,3-羟基克百威为1.0×10-10g;最低检出质量分数均为0.1 mg/kg,各组分的添加回收率为77.8%～94.6%,变异系数为3.86%～6.58%。结论]凝胶渗透色谱净化-气相色谱质谱法测定丁硫克百威及其代谢物在糙米中的残留方法灵敏度、准确度、精密度均符合农药残留分析的要求,可用于检测糙米中丁硫克百威及其代谢物的残留量。

Determination on Residues of Carbosulfan and Its Metabolites in Brown Rice

Objective]The study aimed to monitor and estimate the residues of carbosulfan and its metabolites carbofuran and 3-hydroxycarbofuran in brown rice.Method]A method was established for the simultaneous determination of carbosulfan and its metabolites carbofuran and 3-hydroxycarbofuran in brown rice by gel permeation chromatography(GPC) purification and gas chromatography-mass spectrometry(GC-MS) detection.The tested pesticides components to be measured in the samples were extracted by using the mixed solvent of ethyl-acetate and cyclohexane(1∶ 1,V/V),purified by GPC and neutral Al2O3 solid phase extraction(SPE),and finally detected by GC-MS.Result]The lowest limit of detection(LOD) was 2.0×10-11 g for carbosulfan and carbofuran and 1.0×10-10 g for 3-hydroxycarbofuran.The lowest quantification limit was 0.1 mg/kg for three compounds.The average recovery of each components was 77.8%-94.6% with the relative standard deviation(RSD) of 3.86%-6.58%.Conclusion]The sensitivity,accuracy and precision of the GPC purification and GC-MS detection method for determining the residues of carbosulfan and its metabolites carbofuran and 3-hydroxycarbofuran in brown rice ave all accord with the demands of the pesticide residue analysis,and it is suitable to detect the residues of carbosulfan and its metabolites in brown rice.