发现值仅包括游离氨基酸、水解产生氨基酸的化合物和铵化合物。其原理包括在复合催化剂存在下用硫酸破坏有机物（见ISO 1871），使反应产物碱化，蒸馏释放的氨并收集在硼酸溶液中，然后用标准容量的硫酸溶液滴定。该方法适用于大于0.01%（m/m）的含量。对于含量小于0025%（m/m）的产品，请参见ISO 5378。

The found value only includes free amino acids, compounds producing amino acids on hydrolysis and ammonium compounds. The principle consists in destruction of organic matter by sulphuric acid in the presence of a compound catalyst (see ISO 1871), alkalization of the reaction products, distillation of the liberated ammonia and collection in a boric acid solution, followed by titration with a standard volumetric sulphuric acid solution. The method applies to contents greater than 0,01 % (m/m). For products with contents less than 0,025 % (m/m), see ISO 5378.