An effective method was developed for determination of pyraclostrobin and BF 500-3 residues in pollen and honey of litchi by QuEChERS coupled with ultra performance liquid chromatography-tandem mass spectrometry. The samples were extracted by acetonitrile and cleaned by primary secondary amine(PSA) and C18. In the positive ion mode and multi reaction monitoring mode,the analytes were quantified by the matrix matching standard solutions, and the pretreatment and mass spectrometry conditions were evaluated. The matrix matched standard solutions of pyraclostrobin and its metabolite BF 500-3 showed good linearities in the concentration range of 1-100 μg/L, with the correlation coefficients (R2) of 0.991-0.999. The average recoveries were 87.0%-97.8% with relative standard deviations of 1.3%-3.7%. The limit of detection (LOD) and the limit of quantification(LOQ) were 0.08-0.20 μg/kg and 0.20-0.50 μg/kg,respectively. The method was easy, quick and highly sensitive, and was suitable for quick determination of pyraclotrobin and its metabolites in pollen and honey of litchi.%采用改进的QuEChERS方法结合超高效液相色谱-串联质谱技术,建立了荔枝花粉和花蜜中吡唑醚菌酯及其主要代谢物BF 500-3的分析方法.样品经乙腈提取,分别由乙二胺-N-丙基硅烷(PSA) 和十八烷基键合硅胶吸附剂 (C18) 净化、浓缩后进样分析,正离子扫描、多反应监测模式下,对基质匹配标准溶液定量分析,考察了前处理和质谱分析条件.结果表明,吡唑醚菌酯及其代谢物在1~100 μg/L浓度内,基质匹配标准溶液线性关系良好,相关系数(R2)为0.991~0.999.花粉和花蜜基质中的平均回收率为87.0% ~97.8%,相对标准偏差(RSD)为1. 3% ~3. 7%,检出限(LOD)为0. 08 ~0. 20 μg/kg,定量限 (LOQ)为0. 20 ~0.50 μg/kg.本方法简便、快速、灵敏度高,适于荔枝花粉和花蜜样品中吡唑醚菌酯及其代谢物的快速测定.
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