This part of ISO 8968 | IDF 20 specifies a method for the determination of the non-protein nitrogen content of liquid milk, whole or skimmed.
BS EN ISO 8968-4:2002 history
0000 BS EN ISO 8968-4:2016(2017)
2016BS EN ISO 8968-4:2016 Milk and milk products. Determination of nitrogen content. Determination of protein and non-protein nitrogen content and true protein content calculation (Reference method)
2002BS EN ISO 8968-4:2002 Milk. Determination of nitrogen content. Determination of non-protein nitrogen content