氟吡菌胺及其代谢物在黄瓜中的残留

为评价氟吡菌胺及其代谢物在黄瓜上的安全性，建立了同时检测氟吡菌胺及其代谢物2，6-二氯苯甲酰胺的高效液相色谱-串联质谱法。前处理采用以乙腈提取，无水硫酸镁、石墨化碳（GCB）和乙二胺-N-丙基硅烷（PSA）为分散净化剂的QuEChERS方法，应用高效液相色谱-串联质谱仪在多反应监测（MRM）模式下进行检测。结果表明，在0.05~5 mg·kg^-1的加标范围内，氟吡菌胺和2，6-二氯苯甲酰胺的平均回收率分别为82%~98%和90%~100%，相对标准偏差（RSD，n=5）分别为1.6%~7.9%和3.2%~9.4%，定量检出限（LOQ）为0.05 mg·kg^-1。最终残留试验表明：在氟吡菌胺推荐剂量（735 g·hm^-2）下，施药3次，距最后一次施药间隔1、3 d和5 d时采收，氟吡菌胺及2，6-二氯苯甲酰胺在黄瓜上的最高残留量均小于0.05 mg·kg^-1，低于我国规定的氟吡菌胺在黄瓜中的最大残留限量0.5 mg·kg^-1。该方法前处理过程简单、方便、快速，灵敏度、准确度和精密度均满足残留分析的要求，可用于氟吡菌胺及代谢物2，6-二氯苯甲酰胺在黄瓜中的残留检测。

Fluopicolide residue and its metabolites in cucumber

In order to evaluate the safety of fluopicolide and its metabolites in cucumber, a high-performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)method was developed for the simultaneous determination of fluopicolide and its metabolite 2,6-dichlorobenzamide. The pretreatment method involved acetonitrile extraction. The QuEChERS method was used, in which anhydrous magnesium sulfate, graphitized carbon(GCB), and ethylenediamine-N-propylsilane(PSA)were dispersed as solid-phase purification agents and then detected by multi-reaction ion monitoring with HPLC-MS/MS. Three concentrations of fluopicolide and 2,6-dichlorobenzamide standard solutions were added to the cucumber samples. The results showed that the average recovery rates were 82%~98% and 90%~100%, respectively. The relative standard deviations(n=5)were 1.6%~7.9% and 3.2%~9.4%, respectively. The limit of detection was 0.05 mg·kg^-1, which indicated that it was simpler, faster, and safer than existing assays. The final residue test indicated that the drug was applied at three times at the recommended dose of fluopicolide(735 g·hm^-2). The maximum residual amount of fluopicolide and 2,6-dichloro benzamide in cucumber was less than 0.05 mg·kg^-1 from the last application interval of 1, 3, and 5 d. Both were lower than the maximum residue limit of 0.5 mg·kg^-1 for fluopicolide in cucumber in China. The pretreatment process of this method was simple, convenient, and fast. The method is sensitive, accurate, precise, and meets the requirements of residual analysis, and can be used for the determination of fluoxastrobin and the metabolite 2,6-dichlorobenzamide in cucumber.