Objective To evaluate the uncertainty of the determination of protein content in protein drinks. Methods According to the JJF 1059.1-2012 standard requirement, the main source of uncertainty was analyzed by quantitative determination of protein content in protein beverages, and the relative synthetic standard uncertainty was calculated to evaluate the extended uncertainty. Results The concentration of protein was 5.66 g/100 g and the expanded uncertainty was 0.20 g/100 g (95%, k=2). The uncertainty of the measurement results mostly came from the standard curve fitting, the influence of measurement repeatability and ammonia nitrogen standard solution was the second, while the influence of constant volume and sample weighing could be ignored. Conclusion The evaluation method and results can improve the accuracy of protein detection in practical work.
标题：分光光度法测定蛋白饮料中蛋白质含量的不确定度评定
英文标题：Evaluation of uncertainty in determination of protein content by spectrophotometry determination in protein beverage
