ISO 5983-2:2005 PDF

Scope: This part of ISO 5983 specifies a method for the determination of nitrogen content of animal feeding stuffs according to the Kjeldahl method, and a method for the calculation of the crude protein content. It concerns a semi-micro rapid routine method using block-digestion, copper catalyst and steam distillation into boric acid. The method is applicable to the determination of greater than 0,5 % Kjeldahl nitrogen in animal feeding stuffs, pet foods and their raw materials. The method docs not measure oxidized forms of nitrogen nor heterocyclic nitrogen compounds. The method docs not distinguish between protein nitrogen and non-protein nitrogen. NOTE If it is of importance to determine the content of non-protein-nitrogen, an appropriate method can be used.

ISO 5983-2:2005 Referenced Document

ISO 1871 Food and feed products - General guidelines for the determination of nitrogen by the Kjeldahl method*， 2009-09-01 Update
ISO 385:2005 Laboratory glassware - Burettes
ISO 6498:1998 Animal feeding stuffs - Preparation of test samples

2009 ISO 5983-2:2009 Animal feeding stuffs - Determination of nitrogen content and calculation of crude protein content - Part 2: Block digestion and steam distillation method
2005 ISO 5983-2:2005 Animal feeding stuffs - Determination of nitrogen content and calculation of crude protein content - Part 2: Block digestion/steam distillation method