杜马斯燃烧法与凯氏定氮法测定植物源性饲料原料中粗蛋白质含量的比较

Comparison of Kjeldahl and Dumas combustion methods for the determination of crude protein in feedstuffs

为了比较杜马斯燃烧法和凯氏定氮法测定饲料原料中粗蛋白质含量结果的异同,分别采用杜马斯燃烧法（杜马斯法）和凯氏定氮法（凯氏法）对10类植物源性饲料原料[小麦、次粉、稻谷、木薯、甘薯、米类、菜粕（饼）、杂粕、玉米蛋白粉、玉米胚芽粕]进行了粗蛋白质含量的测定,并对2种方法测定的粗蛋白质含量结果进行了比较分析。结果表明：10类饲料原料的杜马斯法粗蛋白质（D）的质量分数范围为2.23%-66.05%;凯氏法粗蛋白质（K）的质量分数范围为2.32%-63.09%。2种方法测定值之间不存在显著差异（P〉0.05）,且杜马斯法和凯氏法测定结果呈显著线性相关（R2=0.998,P〈0.05）,拟合直线的斜率与1及截距与0之间均不存在显著差异。因此,杜马斯法可以代替凯氏法测定饲料原料中粗蛋白质的含量。

In order to compare the determination of crude protein in feedstuffs by Kjeldahl and Dumas combustion methods, this study was conducted to examine the difference of crude protein in ten kinds of feedstuffs （including wheat, wheat midding, rice, tapioca, sweet potato, rice, rapeseed meal, mixed meal, corn protein powder, and corn germ meal） using Kjeldahl and Dumas combustion methods, respectively. The results indicated that the crude protein of the ten kinds of feedstuffs was between 2.23% and 66.05% for Dumas combustion method, while for Kjeldahl the results were in the ranges of 2.32% and 63.09%. A good linear correlation （R2=0.998, P〈0.05） was obtained between the two different methods, indicating that no significant difference was observed for Kjeldahl and Dumas combustion methods. In conclusion, Dumas combustion method can be used as an alternative for the determination of crude protein in feedstuffs.