液相色谱-串联质谱法测定果蔬中双三氟虫脲、四氯虫酰胺和氰虫酰胺残留

建立了蔬菜和水果中双三氟虫脲、四氯虫酰胺和氰虫酰胺3种新型杀虫剂的分散固相萃取-液相色谱-串联质谱检测方法.样品经乙腈均质提取,混合使用乙二胺-N-丙基硅烷(PSA)和C18基质分散净化剂进行净化,液相色谱-三重四极杆串联质谱(LC-MS/MS)同时进行检测.双三氟虫脲和四氯虫酰胺采用多反应监测负离子模式,氰虫酰胺采用多反应监测正离子模式.双三氟虫脲在苹果、洋葱和经微波处理的洋葱样品中均不存在基质效应,可采用纯溶剂标准外标法或者采用基质匹配标准溶液定量检测; 四氯虫酰胺和氰虫酰胺存在程度不同的基质减弱效应,采用空白基质匹配的校正标准曲线外标法定量.3种杀虫剂均在0.2～100 μg/L线性范围内具有良好的线性关系,相关系数均大于0.9990.在0.005～2.000 mg/kg范围内,平均添加回收率为81.6％～99.9％,相对标准偏差为3.6％～9.8％.氰虫酰胺、四氯虫酰胺和双三氟虫脲的检出限分别为0.064,0.048和0.001 μg/kg,定量限分别为0.210, 0.160和0.004 μg/kg.

Determination of New Bistrifluron,Cyantraniliprole and SYP9080 Residues in Fruits and Vegetables by Liquid Chromatography-Tandem Mass Spectrometry

A liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed for the determination of bistrifluron, cyantraniliprole and SYP9080 residues in fruits and vegetables. The analytes were extracted from samples with acetonitrile, and purified by dispersion solid phase extraction using C18 and primary secondary amine (PSA) as solid phase adsorbent, then analyzed by LC-MS/MS. Bistrifluron and SYP9080 were analyzed with negative ion multiple-reaction monitoring (MRM), cyantraniliprole was analyzed with positive ion MRM. The matrix-induced weakening effect was observed in the analysis of cyantraniliprole and SYP9080 in several samples including cucumber, apple and onion, and the weakening extent of the matrix-induced effect depended on the sample properties. But no matrix effect was found in the analysis of bistrifluron in several samples. The interference of matrix was reduced by using the matrix-matched calibration standards curve in the analysis of cyantraniliprole and SYP9080. Bistrifluron could be quantified by an external standard of the matrix-matched calibration standards or the pure solvent calibration standards. The linear range was from 0.2 μg/L to 100 μg/L for bistrifluron, cyantraniliprole and SYP9080 with the good correlation coefficients (r≥0.9990). The recoveries of cucumber, grape, apple and scallion added bistrifluron at 0.005-2 mg/kg were 79.8％-99.9％, with relative standard deviations (RSD) of 3.6％-9.8％. The limits of quantification (S/N=10) were 0.210 μg/kg, 0.160 μg/kg and 0.004 μg/kg, and limits of detection (S/N=3) were 0.064 μg/kg, 0.048 μg/kg and 0.001 μg/kg for bistrifluron, cyantraniliprole and SYP9080, respectively.