液相色谱-串联质谱法测定葱属蔬菜中的噻虫嗪、多菌灵等5种农药的残留量

Determination of 5 Pesticide Residues in Allium Vegetables by Liquid Chromatography-Tandem Mass Spectrometry

建立了葱属蔬菜（洋葱、大葱和韭菜）中噻虫嗪、噻虫胺、吡虫啉、多菌灵和虫酰肼5种药物残留量的液相色谱-质谱联用法（LC-MS/MS）检测方法。样品用正己烷饱和的乙腈提取,用Qu ECh ERS方法净化,在正离子模式（ESI＋）下,经分时段多反应监测（MRM）模式测定目标化合物,外标法定量。结果表明：5种农药在10-200μg/L的范围内线性关系较好（r2〉0.99）;在5、10、50μg/kg 3个添加水平下,平均回收率在77.3%-104.1%之间;5种农药的定量限（LOQ）均满足国际限量要求。该方法灵敏度高、重现性好、定量准确,可用于葱属蔬菜中上述5种农药残留的日常检测。

A method using liquid chromatography tandem mass spectrometric （LC-MS/MS） for the analysis of thiamethoxam, carbendazim, clothianidin, imidacloprid and tebufenozid in allium vegetables was established. The target compounds were extracted by acetonitrile saturated with hexane and then purified with the QuEChERS method. Five different pesticides were quantified by external standard method with determination in the mode of electrospray positive ionization （ESI＋） and multiple reaction monitoring （MRM）. The calibration curves of five pesticides displayed good linearity within the concentration of 10 to 200 μg/L and the squared correlation coefficients （r2） were larger than 0.99. The average recoveries ranged from 77.3% to 104.1% at three spiked levels of 5, 10,50 μg/kg. The limits of quantitation （LOQs） for all samples met the international limited standard. This method is sensitive and accurate with good reproducibility, which is suitable for the routine assay of the studied pesticide residues in allium vegetables.