A method based on ultra high performance liquid chromatography-tandem mass spectrometry( UHPLC-MS/MS)was established for the determination of fipronil and its metab-olites in feeds.Sodium chloride was added to the samples after the ultrasonic extraction of pure water and acetonitrile,and then cleaned up by the QuEChERS method.The target analytes were separated on a Waters HSS T3 C18column using methanol and water as mobile phases with gradient elution, and detected by a MS/MS system under negative electro-spry ionization (ESI-)and the multiple reaction monitoring( MRM)mode.The limits of detection( LODs) were 0.05 μg/kg,and the limits of quantification( LOQs)were 0.2 μg/kg.The linear correla-tion coefficients were more than 0.999 8.The average recoveries ranged from 92.3% to 105.4%with RSDs no more than 2.3%.This method is suitable for the identification of fipronil and its metabolites in feeds because of its simplicity and high sensitivity.%建立了超高效液相色谱-串联质谱测定饲料中氟虫腈及其代谢物氟甲腈、氟虫腈硫醚和氟虫腈砜的方法.样品经纯水和乙腈超声提取后加入氯化钠盐析,采用 QuEChERS 技术净化,以 Waters HSS T3 C18色谱柱分离,甲醇和纯水为流动相进行梯度洗脱,在多反应监测、负离子模式下进行检测,内标法定量.氟虫腈及其代谢物在各自的范围内呈良好的线性关系,相关系数均大于 0.999 8;氟虫腈及其代谢物的检出限和定量限分别为 0.05 μg/kg 和0.2 μg/kg,加标回收率为92.3%~105.4%,相对标准偏差为0.9%~2.3%( n=5).该法样品前处理过程简单,净化效果好,灵敏度高,适用于各种饲料中氟虫腈及其代谢物含量的测定.
展开▼
