关键词: 气相色谱法；1-油酸-2-棕榈酸-3-亚油酸甘油三酯；不确定度；相对合成标准不确定度；扩展标准不确定度

Abstract: The measurement uncertainty was estimated for the determination of 1-oleic-2-palmitic-3-linoleic acid triglyceride (OPL) content in milk powder by gas chromatography (GC). According to the Measurement and Expression of Uncertainty in Measurement (JJF 1059.1—2012) and the Guidance on Quantifying Uncertainty in Chemical Analysis (CNAS-GL 006: 2019), a mathematical model was established to analyze the sources of measurement uncertainty. The major factors affecting the measurement uncertainty were evaluated. Results showed that the average OPL content of six milk powder samples was measured to be 1.172 g/100 g. The relative expanded uncertainty (urel) was 0.023 6 with a coverage probability of approximately 95%. The standard uncertainty arising from sample preparation was the main source of uncertainty.

Key words: gas chromatography; 1-oleic acid-2-palmitic acid-3-linoleic acid triglyceride; uncertainty; relative synthetic standard uncertainty; expanded standard uncertainty