Uncertainty Evaluation for the Determination of 1-Oleic Acid-2-Palmitic Acid-3-Linoleic Acid Triglyceride Content in Milk Powder by Gas Chromatography

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 (u_rel) was 0.0236 with a coverage probability of approximately 95%. The standard uncertainty arising from sample preparation was the main source of uncertainty.