凯氏定氮法测定蛋白粉中蛋白质含量的不确定度分析

Evaluation of uncertainty for determination of protein in protein powder by Kjeldahl method

目的分析和计算凯氏定氮法测定蛋白粉中蛋白质含量的不确定度。方法依据JJF 1059.1-2011《测量不确定度评定与表示》,建立数学模型,分析不确定度的来源,计算不确定度。结果对蛋白粉中蛋白质进行测定,得出了其相对标准不确定度为0.58%,扩展不确定度为0.2 g/100 g。结论通过测量不确定度的评定,可以掌握凯氏定氮法测定蛋白粉中蛋白质含量结果的准确性,保证检测结果的质量。

Objective To evaluate the uncertainty for determination of protein in protein powder by Kjeldahl meth- od. Methods The mathematical model was established according to JJF1059. 1 - 2011 Evaluation and Expression of Uncer- tainty in Measurement. The sources of uncertainty were analyzed and calculated. Results The protein in protein powder was determined , Thc relative standard uncertainty was 0. 58% ,the expansion uncertainty was 0. 2 g/100 g. Conclusion The evaluation of uncertainty can assure the accuracy of results.