亲水作用液相色谱-电喷雾串联质谱法测定奶制品中三聚氰胺

Hydrophilic interaction liquid chromatography coupled with electrospray tandem mass spectrometry for analysis of melamine residues in milk products

目的:建立牛奶及奶制品中三聚氰胺的亲水作用液相色谱-电喷雾串联质谱法。方法:样品经2.5%甲酸水溶液提取后,用乙腈沉淀蛋白,经微孔滤膜净化,亲水作用色谱柱分离,采用电喷雾串联四极杆质谱进行检测。结果:0.5μg/L～500μg/L时,线性关系良好(r>0.9992)。在1 mg/kg、10 mg/kg和100 mg/kg 3个添加水平范围内的平均回收率为88.6%～97.7%,相对标准偏差小于7.3%,方法检出限为10μg/kg。结论:采用建立的方法测定了液体奶、奶粉、酸奶、奶糖、雪糕、豆奶、奶酪和炼奶等样品,结果表明,该法快速、准确、灵敏,优于传统的HPLC分析方法,适合于生产过程监控和日常检测的高灵敏度确证分析。

Objective：To establish a sensitive method for the analysis of melamine residue in milk and milk products by hydrophilic interaction liquid chromatography coupled with electrospray tandem mass spectrometry.Methods：Samples were extracted with 2.5% formic acid solution.Acetonitrile was used to precipitate proteins.Identification was achieved by electrospray ionization（ESI） in positive mode using multiple reaction monitoring.Results：The lineare range of method was 0.5 μg/L～500 μg/L with correlation coefficient of 0.9992.The detection limit of the method was 10 μg/kg（S/N=10）.The spiked at three levels ranged from 88.6% to 97.7%（n=7）.And the relative standard derivations were lower than 7.3%.Conclusion：The method was sensitive,accurate and precise.It can be used in monitoring quality of milk production and daily analysis of milk products.