固相萃取-超高效液相色谱-串联质谱法测定普洱茶中氟虫腈及其类似物残留

Determination of Fipronil and Its Similar Compounds in Pu'er Tea by Solid-Phase Extraction-Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

【目的】采用TPT固相萃取柱，对普洱茶中的氟虫腈及其类似物残留进行提取和净化，利用超高效液相色谱一串联质谱法进行定性和定量分析。【方法】普洱茶样品经过水润湿后，采用乙腈作为提取溶剂，提取液经TPT固相萃取柱净化后进样分析，采用负离子多反应监测（MRM）模式，外标法定量。【结果】氟虫腈及其类似物在0．05～5μg/L范围内线性关系良好，经过TPT相萃取柱的净化后，氟虫腈及其类似物检出限都为0．003μg／kg，在0．05μg／kg添加质量分数下平均回收率范围为93．4％～97．1％，相对标准偏差范围为5．5％-7．1％。【结论】该方法简便、灵敏度高，能够有效去除普洱茶中的干扰物质，适于普洱茶中氟虫腈及其类似物的测定。

[Aims] A method for qualitative and quantitative analysis of fipronil and its similar compounds residues in Pu＇er tea by using TPT solid-phase extraction column and ultra performance liquid chromatography-tandem mass spectrometry was developed. [Methods] The Pu＇er tea sample was wetted by water and extracted by acetonitrile, and the extract was purified by TPT solid-phase extraction column and analyzed under negative ion mode and multiple reaction monitoring （MRM）. In addition, the results were quantified by the external standard method. [Results] The method showed good linearity when the concentrations of fipronil and its similar compounds were in the range of 0.05 to 5 μg/L. After purification by TPT solid-phase extraction column, the limits of detection for fipronil and its similar compounds ware all 0.003 μg/kg. When the addition level was 0.05 μg/kg, the average recoveries for fipronil and its similar compounds were in the range of 93.4 to 97.1%, and the relative standard deviations were in the range of 5.5 to 7.1%. [Conclusions] The method is simple, highly sensitive, and can separate the interfering substances in Pu＇er tea, which is suitable for the determination of fioronil and its similar compounds in Pu＇er tea.