滴定法测定饼干中油脂过氧化值的不确定度评定

目的评定滴定法测定饼干中油脂过氧化值的不确定度。方法建立饼干中油脂过氧化值测定不确定度的数学模型,采用滴定法测定饼干中油脂的过氧化值,分析该方法测量不确定度的主要来源并对其进行评定,确定不确定度的分量,合成标准不确定度。结果当样品的过氧化值为0.0660g/100g,其扩展不确定度为0.0011 g/100 g (k=2),结果表示为(0.0660±0.0011)g/100 g (k=2)。结论影响最终测量不确定度主要来自于样品重复测定过程、样品称样量和滴定体积。

Uncertainty evaluation for the determination of peroxide value in biscuits by titration

Objective To evaluation the uncertainty of determination of peroxide value in biscuits by titration. Methods The peroxidation value of oil in biscuit was determined by titration method. A mathematical model was established for evaluating the uncertainty. The main sources of measurement uncertainty of this method were analyzed and evaluated, the components of uncertainty were determined, and the standard uncertainty was synthesized. Results When the peroxide value of the sample was 0.0660 g/100 g, its extended uncertainty was 0.0011 g/100 g (k=2), and the result was expressed as (0.0660±0.0011) g/100 g (k=2). Conclusion The final measurement uncertainty is mainly from the sample repeat measurement process, sample weight and titration volume.