液相色谱-串联质谱检测鸡蛋中氟虫腈及其代谢物的残留量

目的建立一种检测鸡蛋中氟虫腈及其代谢物残留的液相色谱-串联质谱(LC-MS/MS)定量分析方法。方法优化检测条件:用乙腈进行样品提取,选择C18固相萃取小柱和无水硫酸镁对提取样品净化后进行液质联用检测。结果经过优化后液相条件:流动相由2mmol/L的甲酸铵水溶液和甲醇组成,采用梯度洗脱方式在C18反相色谱柱中进行分离,进样量为4μL。质谱条件:离子源采用ESI负离子,通过SRM模式对样品中氟虫腈及其代谢物进行定量检测。优化后,氟虫腈及其代谢物在0~20ng/mL质量浓度范围内线性关系良好,R2均>0.9993,检出限(S/N=3)和定量限(S/N=10)分别0.2~0.4μg/kg和0.66~1.32μg/kg。实际样品中添加4.0、20.0、40.0μg/kg 3个质量浓度水平下,平均回收率在76.60%~98.24%,相对标准偏差(RSD)为1.03%~3.41%,符合定量检测要求。结论该方法操作简便、灵敏度高,可满足鸡蛋中氟虫腈及其代谢物的检测要求。

The determination of fipronil and its metabolites in eggs by LC-MS/MS

Objective To establish a method for the determination of fipronil and its metabolites in eggs by liquid chromatography coupled tandem mass spectrometry(LC-MS/MS).Methods The detection parameters were optimized.The samples were extracted by acetonitrile and further purified by C18-SPE and anhydrous magnesium sulfate then subjected to analysis by LC-MS/MS.Results Under the optimal conditions:mobile phase was composed of 2 mmol/L Ammonium formate solution and methanol;the C18 reversed-phase column was used for seperation by gradient elution.The volume of injection is 4μL.The MS detection was performed under ESI ironic source,SRM model was used for quantitative analysis of fipronil and its metabolites.After optimazation,good linear correlation(R2>0.9993)was observed in the range of 0.0-20.0 ng/mL for fipronil and its metabolites.The limits of detection(S/N=3)and limits of quantitation(S/N=10)were 0.2-0.4μg/kg and 0.66-1.32μg/kg,respectively.The recovery rates were in the range of 76.60%-98.24%under spiked concentration of 4.0,20.0,and 40.0μg/kg,respectively;the relative standard deviations(RSDs)were in the range of 1.03%-3.41%,which satisfied the requirements for quantitative determination.Conclusions The established method for detection of fipronil and its metabolites is simple with high sensitivity,which can meet the requirements for detection of fipronil and its metabolites in eggs.