液态奶中三聚氰胺含量的测量不确定度评定

依据国标GB/T 22388-2008规定,采用高效液相色谱法对液态奶中三聚氰胺的含量进行了检测。建立数学模型,分析确定检测液态奶中三聚氰胺含量的不确定度来源,并对测量过程中的不确定度分量进行逐层分析与合成,得到合成标准不确定度和扩展不确定度分别为0.054 mg/kg和0.11 mg/kg。计算结果显示由样品溶液测量重复性、标准溶液测量重复性、标准溶液配制过程引入的不确定度分量对合成标准不确定度贡献较大,是不确定度的主要来源;由样品称量、定容引入的不确定度相对来说较小。

Uncertainty of Measurement in Determination of Melamine in Liquid Milk

According to GB/T 22388-2008, melamine in liquid milk is detected with HPLC. The uncertainty of the measurement in determination of melamine in liquid milk is analyzed and processed by mathematical model. On the basis of analyzing the different parts of the uncertainty, the combined standard uncertainty and the expanded uncertainty are acquired, they are 0.054 mg/kg and 0.11 mg/kg respectively. The result shows that the major uncertainty of the measurements are comprised by the measurement repeatability of the sample solution and standard solution and the uncertainty leading by preparing sulation, the minor parts are the uncertainty leading by weighing and fixing of the samples.