分光光度法测定大豆蛋白纤维中蛋白质含量的不确定度评定

Evaluation of uncertainty in the determination of protein content in soybean protein fiber by spectrophotometry

为进一步了解检测过程中的影响因素,科学准确地表征检测结果,对分光光度法测定大豆蛋白纤维中蛋白质含量的不确定度进行了评定。依据试验原理建立数学模型,通过对样品称样量、氨氮标准溶液配制、曲线绘制以及重复性等影响结果的各个因素进行定量分析,进而评价不确定度。结果显示,大豆蛋白纤维中蛋白质质量分数为7.16%,扩展不确定度约为0.05%,不确定度的主要影响因素是标准曲线的绘制,其次是测量的重复性。

In order to further understand the influencing factors in the detection process and to scientifically and accurately characterize the detection results,the uncertainty of the determination of protein content in soybean protein fiber by spectrophotometry was evaluated.Based on the principle of experiment,the mathematical model was established by analyzing and quantifying the factors influencing the results,such as sample size,configuration of ammonia nitrogen standard solution,curve drawing and repeatability,etc.Then the uncertainty was evaluated.The evaluation results showed that the protein content of soybean protein fiber was 7.16%,and the expanded uncertainty was 0.05%.The main influencing factor of the uncertainty was the drawing of standard curve,followed by the effect of measurement repeatability.