超高效液相色谱串联质谱法快速测定乳及乳制品中三聚氰胺

摘要

建立快速、经济测定乳及乳制品中三聚氯胺的超高效液相色谱-串联质谱(UPLC-MS/MS)分析方法.乳及乳制品样品中加入乙腈-水溶液,通过超声波提取和二氯甲烷液液萃取除去蛋白质、脂肪等杂质,迸一步稀释后直接进样.经超高效液相色谱(UPLC)快速分离,采用电喷雾正离子(ESI+)多反应监测模式(MRM),实现对三聚氰胺的定性和外标法定量.乳及乳制品样品在1.2 min内完成分析,且具有良好的线性关系(r =0.999 1);方法检出限和定量限(LOQ)分别为0.005 mg/kg、0.017 mg/kg;在0.5～ 100 μg/L的基质添加浓度范围内,平均回收率为91.3％ ～97.1％,相对标准偏差(RSD)小于9.03％.%A rapid and economic ultra performance liquid chromatography-tandem mass spectrometry method is developed and validated for the determination of melamine in milk and milk products. The method includes a simple acetonitrile-water extraction, and ultrasound treatment and dichloromethane liquid-liquid extraction to remove protein and fat. The purified extract is further diluted before injection on ACQUITY UPLC BEH HILIC. A positive ion elec-trospray ionization ( ESI+) and multiple reaction monitoring mode (MRM) are then applied. The samples are quantified by external standard method. A total analysis was done within 1. 2 min with a good linear relationship ( r ＞ 0.9991). The limit of detection and the limit of quantification were 0.005 andO. 017 mg/kg, respectively. The spiked recoveries are within 91. 3% -97. 1 % at the spiked levels of 10 -400 μg/L for melamine with relative standard deviation (RSD) below 9.03%. This method is rapid, economic, accurate and sensitive, suitable for screening and detection melamine in milk and milk products.