This part of ISO 14673 / IDF 189 specifies a method for the determination of the nitrate and nitrite contents of milk and milk products by cadmium reduction and spectrometry. The method is applicable to - whole and partly skimmed and skimmed dried milk; - hard, semi-hard and soft cheeses; - processed cheese; - whey cheese, caseins and caseinates and dried whey. The method may be performed using automatic equipment, in particular by segmented flow analysis (SFA) or flow injection analysis (FIA), thus reducing cadmium contamination in laboratory work places and waste water. NOTE These methods are described in ISO 14673-2 / IDF 189-2 and ISO 14673-3 / IDF 189-3, respectively.