液相色谱-串联质谱法测定鸡蛋中氟虫腈及其代谢物的残留量

Determination of the Residues of Fipronil and Its Metabolites in Eggs by Liquid Chromatography-tandem Mass Spectrometry

建立一种采用液相色谱-三重四级杆质谱测定鸡蛋中氟虫腈及其代谢物(氟甲腈、氟虫腈砜和氟虫腈硫醚)的快速筛查方法。鸡蛋样品经乙腈和正己烷提取,C18固相萃取柱净化,Shim-pack XR-ODSⅢ色谱柱(2.0 mm i.D×150 mm,2.1μm)分离,以乙腈-5 mmol/L乙酸铵(0.02%甲酸)水溶液为流动相,梯度洗脱,外标法定量。采用液相色谱-三重四级杆串联质谱动态多反应监测模式,以负离子采集进行定性筛查和定量分析。结果表明,氟虫腈及其代谢物在0～50μg/L质量浓度范围内线性关系良好,相关系数R2均大于0.999。以10倍信噪比确定各药物的定量限(LOQ),氟虫腈及其代谢物的定量限为0.3～0.6μg/kg。在0.5、5.0和10.0μg/kg添加水平下,氟虫腈及其代谢物的平均回收率为92.3%～105.1%,相对标准偏差(RSD)为1.2%～8.6%。该方法简便、快速、灵敏,适用于鸡蛋中氟虫腈及其代谢物的快速筛查和定量检测。

A rapid screening method was developed for the determination of the residues of fipronil and its metabolites(fipronil-desulfinyl,fipronil sulfone and fiproil sulfide) in eggs by liquid chromatography triple quadrupole mass spectrometry(LC-MS/MS).Egg samples were extracted with acetonitrile and n-hexane.The obtained extract was purified by a C18 solid phase extraction(SPE) column and further separated using a Shim-pack XR-ODS columnⅢ(2.0 mm I.D.× 150 mmL.,2.1 μm particle size) with a mobile phase in gradient elution(acetonitrile-5 mmol/L ammonium acetate(0.02% formic acid).Qualitative screening and quantitative analysis were performed by LC-MS/MS with dynamic multiple reaction monitoring(DMRM) mode and in negative ion mode,and quantification was carried out by the external standard method.The results showed that good linearity was detected for fipronil and its metabolites in the range of 0~50 μg/L,with the correlation coefficient R2 greater than 0.999.The limit of quantification(LOQ) of fipronil and its metabolites was 0.3~0.6 μg/kg at the signal-to-noise ratio of 10.The average recovery of fipronil and its metabolites at the spiking levels of 0.5,5.0 and 10.0 μg/kg ranged from 92.3% to 105.1%,with the relative standard deviation(RSD,n=6) in the range of 1.2%~8.6% The method was proven to be simple,rapid andsensitive,and suitable for rapid screening and quantitative detection of fipronil and metabolite residues in eggs.