液相色谱法测定牛奶中三聚氰胺残留量的不确定度

通过数学建模,对GB/T22388-2008中HPLC法测定牛奶中三聚氰胺残留量的不确定度进行分析。将各个分量分化,运用最小二乘法对标准曲线拟合的不确定度,用极差法对测定次数较少时引起的不确定度,添加回收率的不确定度等进行分析。结果表明,合成标准不确定度U（X）=0.040,当取样量为2.00g,k=2（95%置信度）时,测得牛奶中三聚氰胺的含量为（2.00±0.160）mg/kg。

HPLC method for the determination of melamine residues uncertainty in milk

The purpose of this study was to analyze the determination uncertainty of the melamine residue in milk which was determined by establishing HPLC method,according to GB/T 22388-2008,the mathematical modeling was set up.Specifically,each component of the uncertainty needed to be analyzed,including analyzing the fitness uncertainty of the standard curve with the minimum squares method,analyzing the uncertainty accentuated by the deficiency in determinations and the uncertainty of the recovery with the range method,etc.The result showed that the combined standard uncertainty was 0.040,the melamine content of the milk was（2.00±0.160） mg/kg when the amount of sample was 2.00 g and k=2（The confidence degree was 95%）.