QuEChERS-超高效液相色谱-串联质谱分析氰霜唑及代谢物CCIM在黄瓜和土壤中的残留

建立了QuEChERS-超高效液相色谱-串联质谱 (UPLC-MS/MS) 同时检测黄瓜和土壤中氰霜唑及代谢物4-氯-5-(4-甲苯基)-1H-咪唑-2-腈 (CCIM) 残留的方法。样品经V (乙酸) : V (乙腈) = 1 : 99混合溶液提取，以XBridge-C₁₈色谱柱 (150 mm × 2.1 mm，3.5 μm) 进行UPLC 分离，采用三重四极杆串联质谱以正离子多重反应监测模式 (MRM) 进行测定。结果表明:在0.005~1 mg/kg范围内，氰霜唑及CCIM的峰面积与其对应的质量浓度间线性关系良好， R2 > 0.999，在0.01、0.05和0.1 mg/kg添加水平下，氰霜唑在黄瓜和土壤中的回收率为84%~95%，相对标准偏差 (RSD) 为1.2%~3.3%；CCIM的回收率为84%~103%，RSD为2.0%~3.9%。氰霜唑在黄瓜和土壤中消解动态符合一级动力学方程，消解较快，在黄瓜和土壤中的半衰期分别为1.7~4.0 d，6.6~9.6 d。该方法样品前处理过程简单快速，分析时间短，灵敏度、准确度及精密度均符合农药残留检测要求，适用于黄瓜中的氰霜唑及CCIM残留的检测。

Determination of cyazofamid and its metabolite CCIM residue in cucumber and soil with a modified QuEChERS method by ultra performance liquid chromatography-tandem mass spectrometry

A reliable QuEChERS-ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis method was developed for residual simultaneous determination of cyazofamid and its metabolite, 4-chloro-5-p-tolylimidazole-2-carbonitrile (CCIM), in cucumber and soil. The samples were extracted by V (acetic acid) : V (acetonitrile) = 1:99, and separated by UPLC with a waters XBridge-C₁₈ column (150 mm × 2.1 mm, 3.5 μm). Targeted compounds were analyzed using UPLC-MS/MS in multiple reaction monitoring (MRM) mode via positive electrospray ionization (ESI+). Under the optimum condition, when the concentrations of cyazofamid and CCIM were 0.005-1 mg/kg, the linear relation was great (R2 > 0.999). When the fortification levels were 0.01, 0.05 and 1 mg/kg, the recoveries of cyazofamid in cucumber and soil were 84%-95% with relative standard deviations (RSD) of 1.2%-3.3%, and the recoveries of CCIM was 84%-103% with RSD of 2.0%-3.9%. The dissipation dynamics of cyazofamid in soil and cucumber accorded with the first-order kinetics equation. The half-lives of cyazofamid in cucumber was 1.7-4.0 d, and in soil was 6.6-9.6 d, respectively. This method is simple, rapid and time-saving. As the sensitivity, accuracy and precision are satisfied with the requirements of the pesticide residues analysis.