A comparison of the Kjeldahl and Dumas methods for the determination of protein in foods, using data from a proficiency testing scheme
A comparison of the Kjeldahl and Dumas methods for the determination of protein in foods, using data from a proficiency testing scheme
复制标题
DOI：
10.1039/b208973b
复制
发表时间：
2002-01-01
期刊：
影响因子：
4.2
通讯作者：
Damant, A
中科院分区：
文献类型：
--
作者：
Thompson, M;Owen, L;Damant, A
目前，凯氏定氮法和杜马斯法均用于测定食品中的蛋白质，但用于将测定的氮含量转换为蛋白质含量的经验氮因子仅基于凯氏定氮法。因此，两种方法之间的不等效可能会导致一些实验室报告不正确的蛋白质含量。我们在此报告一项使用能力验证计划结果中多年积累的数据的研究。平均而言，杜马斯法提供的结果比凯氏定氮法高约 1.4%，但两种方法之间的差异取决于食品类型。批判性地讨论了寻找分析方法之间偏差的方法。
Both the Kjeldahl and the Dumas methods for the determination of protein in foodstuffs are currently in use, but the empirical nitrogen factors used to convert the determined nitrogen content to protein content are based on the Kjeldahl method alone. Non-equivalence between the two methods could therefore result in some laboratories reporting an incorrect protein content. We report here a study using data accumulated over several years in the results of a proficiency testing scheme. On average the Dumas method provided results that were relatively higher by about 1.4% than the Kjeldahl method, but the difference between the methods depended on the type of foodstuff. The methodology of looking for bias between analytical methods is critically discussed.