QuEChERS-四极杆/静电场轨道阱高分辨质谱测定动物性食品中氟虫腈及其代谢物残留

基于低温处理和QuEChERS方法,采用超高效液相色谱-四极杆/静电场轨道阱高分辨质谱建立了动物性食品中氟虫腈及其代谢物残留的分析检测方法。样品采用乙腈提取,经低温处理,N-丙基乙二胺(PSA)和C18粉分散固相萃取(d-SPE)净化,以BEH C18色谱柱为分析柱,乙腈-0.1%乙酸溶液为流动相进行梯度洗脱分离,外标法定量。采用高分辨质谱平行反应监测(PRM)扫描模式,以负离子采集进行定性筛查和定量分析。氟虫腈及其代谢物在0.02~2μg/L和0.2~20μg/L质量浓度范围内均呈良好的线性关系,相关系数(r2)大于0.992。对液体或半液体样品(如牛奶和鸡蛋)和固体样品(如鸡肉),方法的定量下限分别为0.1μg/kg和0.2μg/kg。在不同浓度的加标水平下,氟虫腈及其代谢物在鸡蛋中的平均回收率为81.6%~96.9%,相对标准偏差(RSD)为1.3%~11.5%;在鸡肉中的平均回收率为81.2%~96.0%,RSD为3.4%~11.4%;在牛奶中的平均回收率为79.1%~100.1%,RSD为1.5%~10.7%。该方法简单、灵敏、准确,适用于动物性食品中氟虫腈及其代谢物的快速筛查和定量检测,方法的灵敏度满足欧盟的残留限量要求。

Determination of Fipronil and Its Metabolites in Animal Derived Foods by QuEChERS Method Combined with Ultra Performance Liquid Chromatography-High-resolution Benchtop Q Exactive Mass Spectrometry

Based on cryogenic treatment and QuEChERS method,an ultra performance liquid chromatography-high-resolution benchtop Q Exactive mass spectrometry method for the determination of fipronil and its metabolites in animal derived foods was established.The samples were extracted with acetonitrile,and cleaned up by the cryogenic treatment and dispersive solid phase extraction(d-SPE) with the N-propylethlene diamine(PSA) and C18.The chromatographic analysis was performed on a BEH C18 column with 0.1％ acetic acid and acetonitrile as mobile phase by gradient elution,and the external standard calibration was used for quantification.The negative ion acquisition mode was ap plied,and the quantitative analysis was carried out by high resolution mass spectrometry using parallel reaction monitoring(PRM) mode.Fipronil and its metabolites showed good linearities in the concentration ranges of 0.02-2 μg/L and 0.2-20 μg/L,with the correlation coefficients (r2) above 0.992.For liquid or semi-liquid samples (such as milk and eggs)and the solid samples (such as chicken),the limits of quantification(LOQs) for 4 analytes were between 0.1 μg/kg and 0.2 μg/kg.At different spiked levels,the average recoveries of fipronil and its metabolites in eggs,chicken and milk were in the ranges of 81.6％-96.9％,81.2％-96.0％ and 79.1％-100.1％,with the relative standard deviations(RSDs) of 1.3％-11.5％,3.4％-11.4％ and 1.5％-10.7％,respectively.The method was simple,sensitive and accurate,and was suitable for the rapid screening and quantitative analysis of fipronil and its metabolites in animal derived foods,and the sensitivity of the method could meet the requirement for residual limitation of EU.