气相色谱-负化学源电离-质谱法测定蔬菜中氟虫腈及其代谢物残留

Determination of Fipronil and Its Metabolites in Vegetables by Gas Chromatography-Negative Ion Chemical Ionization-Mass Spectrometry

建立气相色谱-负化学源电离-质谱法测定蔬菜中氟虫腈及其3种代谢物氟甲腈、氟虫腈砜和氟虫腈亚砜残留量的方法。样品以乙腈提取,QuEChERS方法净化,采用基质校正曲线外标法定量。结果表明,氟虫腈及其代谢物在0.2~10.0μg/L质量浓度范围内呈良好的线性关系;在1.0、5.0μg/kg和10.0μg/kg 3个添加水平下,氟虫腈及其3种代谢物的回收率在88.9%~105.8%之间,相对标准偏差在2.2%~7.6%之间;方法的检出限在0.2~0.3μg/kg之间,定量限为1.0μg/kg。该方法快速、简便、灵敏、准确,适用于蔬菜中氟虫腈及其代谢物残留的检测。

A method was developed for the determination of fipronil and its three metabolites including fluorocarbonitrile,fipronil sulfone and fipronil sulfide in vegetables by gas chromatography-negative ion chemical ionization-mass spectrometry(GC-NCI/MS).The target compounds were extracted from samples with acetonitrile,and then purified by the QuEChERS method before analysis.Quantification was performed using a matrix-matched calibration curve with external standards.The results indicated that the linearity of the method was good in the concentration range between 0.2 and 10.0μg/L,and the average recoveries were 88.9%-105.8%with relative standard deviations(RSDs)of 2.2%-7.6%at three spiked levels(1.0,5.0 and 10.0μg/kg).The limits of detection(LODs)were 0.2-0.3μg/kg,and the limit of quantification(LOQ)was1.0μg/kg.The developed method was simple,sensitive and accurate,and could be used for the routine analysis of the re sidues of fipronil and its three metabolites in vegetables.