LC-MS/MS内标法测定乳制品中的三聚氰酸

Determination of Cyanuric Acid in Dairy Products by HPLC-MS/MS

建立快速测定乳制品中三聚氰酸残留量的高效液相色谱-串联质谱分析方法。用乙腈和水提取样品中的三聚氰酸,乙腈二次去蛋白,10000r/min离心后,以电喷雾离子源负离子多反应监测模式进行质谱分析,内标法定量。三聚氰酸在0.005～0.2μg/mL范围内线性关系良好,相关系数r>0.999。在空白样品中添加三聚氰酸的平均回收率在91.7%～99.6%之间,相对标准偏差<10%。液态奶类样品和奶粉的定量限均为0.2mg/kg。

A sensitive HPLC-MS/MS method with high selectivity was developed for the determination of cyanuric acid residues in dairy products. Cyanuric acid in samples was extracted into acetonitrile/water system. The extract was deproteinized by adding additional acetonitrile,followed by high-speed centrifugation,before HPLC-MS/MS analysis in the internal standard mode. Electrospray ionization was applied and operated in the negative ion mode. An excellent linear range of this method for the determination of cyanuric acid was 0.005-0.2μg/mL with a correlation coefficient of more than 0.999. The average recovery rates in dairy products spiked with standard material at concentration levels of 0.2,0.5,1.0 mg/kg and 2.0 mg/kg were in the range of 91.7% to 99.6% with relative standard deviations less than 10%. The limit of detection of this method was 0.2 mg/kg.