Colorimetric Determination of Ammonia in Milk and Dry Products of Milk

Abstract
A colorimetric method for detn. of ammonia in milk and dry products of milk is described. It is based on the reaction of ammonia with alkaline phenol and sodium hypochlorite. It is rapid, and reproducibility is good. The NH3 content of fluid milk and of some dry milk products varies appreciably, with dry whey solids having the highest NH3 content.