液相色谱-串联质谱法测定奶粉中三聚氰胺的不确定度评定

Uncertainty Estimation in Process of Melamine Determination in milk powder by Liquid Chromatography-tandem Mass Spectrometry (LC-MS/MS)

根据实验过程的数学模型,分析了液相色谱-质谱法测定奶粉中三聚氰胺的不确定度来源来自四个部分:①标准物质引入的不确定度;②最小二乘法拟合标准曲线校准得出C时所产生的不确定度;③样品制备过程引入的不确定因素;④测试过程随机效应导致的不确定度。对各个不确定度分量分别进行了计算,并计算出合成不确定度及扩展不确定度,并对不确定度进行了评价,提出今后该方法的改进方向为改善样品前处理过程。

The uncertainty during process of melamine determination in milk powder by liquid chromatography-tandem mass spectrometry （LC-MS/MS） was estimated based on the mathematical model. The uncertainty sources were identified as four parts, standard solution preparation, sample preparation, sample determination using calibration curve and random effect during determination. Each source was quantified in detail. Finally, combined standard uncertainty as well as expanded uncertainty was calculated.