关键词: 三聚氰胺, 气相色谱-质谱联用法, 不确定度评定

Abstract: Objective To evaluate the uncertainty of determination of melamine residue in milk powder by gas chromatography-mass spectrometry. Methods According to the third method in GB/T 22238-2008 《Methods for the Determination of Melamine in Raw Milk and Dairy Products》: Gas chromatography-mass spectrometry, combined with CNAS-GL006 Uncertainty Evaluation Guide for Chemical Analysis, a mathematical model was established to analyze and evaluate the sources of uncertainty during the experiment, and the synthetic standard uncertainty obtained from each uncertainty was calculated. Results When the content of melamine was 2.09mg/kg, the extended uncertainty was 0.182mg/kg (k=2). Conclusions The uncertainty of test results mainly comes from sample recovery, repeatability, standard solution preparation and curve fitting.

Key words: Melamine, Gas chromatography-mass spectrometry, Evaluation of uncertainty