该研究建立了QuEChERS-液相色谱-串联质谱法同时测定南瓜中噻虫胺和氟啶虫胺腈残留量的分析方法。样品中的噻虫胺和氟啶虫胺腈经乙腈均质提取和基质分散萃取法净化，净化后的样液经0.22 μm滤膜过滤后，采用液相色谱-串联质谱法测定。采用C18色谱柱分离，电喷雾离子化、正离子扫描方式和动态多反应监测模式检测，基质匹配标准溶液外标法定量。噻虫胺在2.5~100 μg/L（氟啶虫胺腈在0.5~20 μg/L）的范围内线性关系良好，相关系数分别为0.9994和0.9988。噻虫胺在5、10和50 μg/kg（氟啶虫胺腈在1、2和10 μg/kg）的3个添加水平的平均回收率在88.5%~111.2%之间，相对标准偏差（RSD，n=6）在1.12%~6.92%。噻虫胺和氟啶虫胺腈的方法定量限分别为1.0 μg/kg和5.0 μg/kg。该方法快速简便、灵敏度高、重现性好，可满足南瓜中噻虫胺和氟啶虫胺腈的残留检测要求。

A QuEChERS-liquid chromatography-tandem mass spectrometry method was established for the simultaneous determination of clothianidin and sulfoxaflor residues in pumpkin. The clothianidin and sulfoxaflor were extracted with acetonitrile from the samples subjected to homogenization, purified by the matrix solid-phase dispersion method, filtered through a 0.22 μm filter membrane and analyzed by LC-MS /MS. The detection was performed after separation using a C18 chromatographic column, electrospray ionization, positive ion scanning mode and dynamic multi-reaction monitoring mode, and quantification was conducted by the matrix-matched external standard calibration. A linear relationship was found within the range of 2.5~100 μg/L for clothianidin and 0.5~20 μg/L for sulfoxaflor, with their correlation coefficients as 0.9994 and 0.9988, respectively. The average recoveries were 88.5%~111.2% at the three spiking levels of 5, 10 and 50 μg/kg for clothianidin, and 1, 2 and 10 μg/kg for sulfoxaflor, with the relative standard deviations in the range of 1.12%~6.92%. The limits of quantification (LOQs) were 1.0 and 5.0 μg/kg for clothianidin and sulfoxaflor respectively. The method is rapid, simple, sensitive, and reproducible, and can meet the requirements for the determination of clothianidin and sulfoxaflor residues in pumpkin.

上海市食品质量安全检测与评价专业技术服务平台(18DZ2292400)