ISO 6739:1988

Whey cheese — Determination of nitrate and nitrite contents — Method by cadmium reduction and spectrometry

Is suitable for all kinds of whey cheese. The principle of determination consists in extracting the whey cheese with warm water, precipitating the fat and proteins, filtering and reducing the nitrate in a portion of the filtrate to nitrite by means of copperized cadmium. The apparatus for nitrate reduction is shown in a figure.