ISO 5549:1978 酪蛋白和酪蛋白酸盐.蛋白质含量的测定（参比法）

标准编号：ISO 5549:1978

中文名称：酪蛋白和酪蛋白酸盐.蛋白质含量的测定（参比法）

英文名称：Caseins and caseinates — Determination of protein content (Reference method)

发布日期：1978-06

标准范围

不适用于含有酪蛋白酸铵或其他铵化合物或其他含氮非蛋白化合物的酪蛋白和酪蛋白酸盐。测定原理包括在硫酸铜（II）催化下，用硫酸钾和硫酸的混合物消化试样，将有机氮转化为氨氮，蒸馏并吸收硼酸溶液中的氨，用标准容量盐酸溶液滴定，再滴定乘以系数6.38。

Does not apply to caseins and caseinates containing ammonium caseinate or other ammonium compounds, or other nitrogenous nonprotein compounds. The principle of determination consists in digesting a test portion with a mixture of potassium sulphate and sulphuric acid, in the presence of copper(II) sulphate as catalyst, to convert organic nitrogen into ammoniacal nitrogen, distilling and absorbing the ammonia in boric acid solution, titrating with standard volumetric hydrochloric acid solution and multiplying the resualt by the factor 6.38.

标准预览图