固相萃取-UPLC-MS/MS法测定牛奶中氟虫腈及其代谢物残留量

建立一种固相萃取-超高效液相色谱-串联质谱法同时测定牛奶中氟虫腈及其代谢物(氟甲腈、氟虫腈砜、氟虫腈硫醚)的分析方法。牛奶样品经提取和盐析,Oasis PRiME HLB固相萃取柱通过式净化后,以乙腈-水为流动相,HSS T3色谱柱(2.1mm×100 mm,1.8 μm)进行色谱分离,在电喷雾负离子模式下,多反应监测(MRM)方式进行测定,外标法定量。结果表明,氟虫腈及其代谢物在0.05~5.0 μg/L浓度范围内均呈良好的线性关系,相关系数r≥0.9976,方法检出限为0.01 μg/kg,定量限为0.05 μg/kg。在浓度分别为0.5、1、10 μg/kg加标水平下,4种化合物的回收率范围为80.6%~101%,相对标准偏差范围为1.0%~6.1%。该方法简单快捷、准确可靠,适用于牛奶中氟虫腈及其代谢物的同时测定。

Determination of Fipronil and Its Metabolites Residues in Milk by Solid-Phase Extraction-UPLC-MS/MS

A method for the simultaneous determination of fipronil and its metabolites(fipronildesulfiny,fipronilsulfone and fipronil sulfide)residues in milk was developed by ultra high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS). The milk sample was extracted and salted out,and the Oasis PRiME HLB solid phase extraction column was purified by pass-through purification. The acetonitrile-water was used as mobile phase,and the HSS T3 column(2.1 mm×100 mm,1.8 μm)was chromatographed in electrospray negative ion mode. Then,the multiple reaction monitoring (MRM) method was used for measurement,and external standard method was used for quantification.The results showed that,the fiproniland its metabolites showed a good linear in the range from 0.05 to 5.0 μg/L,and the correlation coefficients r≥0.9976. The limits of detection(LODs)were 0.01 μg/kg and the limits of quantification(LOQs)were 0.05 μg/kg. At spiked levels of 0.5,1,10 μg/kg,the recoveries of the four target analytes were between 80.6% and 101%. The relative standard deviations were between 1.0% and 6.1%. The method was simple and sensitive,and couldbe suitable for the analysis of fipronil and its metabolites residues in milk.