葵花籽油中酸价测量结果的不确定度评价

目的 分析食用油中酸价测定的不确定度来源并建立不确定度评定方法, 为检验数据的可靠性和准确性提供参考。方法 依据GB 5009.229-2016《食品安全国家标准 食品中酸价的测定》和JJF 1059.1-2012《测量不确定度评定与表示》建立数学模型, 计算各变量的不确定度, 最终计算扩展不确定度。结果 结果显示, 样品中酸价的扩展不确定度为U=1.764×10?3 mg/g, 样品中酸价含量为(0.16±0.002) mg/g(置信水平95%, 包含因子k=2)。结论 在测定过程中, 测量重复性对总的不确定度影响最大, 其次是滴定管的体积。

Evaluation of uncertainty of measurement results of acid value of sunflower oil

Objective To analyze the sources of uncertainty of determination of acid value in edible oil, establish a method of uncertainty evaluation, and provide a reference for the reliability and accuracy of test data. Methods According to GB 5009.229 2016 National food safety standard-Determination of acid value in food and JJF 1059.1-2012 Evaluation and representation of measurement uncertainty, mathematical model was established, the uncertainty of each variable was calculated and extended uncertainty was finally calculated. Results The results showed that the expanded uncertainty of the acid value in the sample was U=1.764×10?3 mg/g, and the acid value content in the sample was (0.16±0.002) mg/g (confidence level was 95%, including factor was k=2). Conclusion In the measurement process, the measurement repeatability has the greatest influence on the total uncertainty, followed by the volume of the burette.