EN ISO 14673-1:2004

Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Principle
5 Reagents
6 Apparatus
7 Sampling
8 Preparation of test sample
   8.1 Dried milk and dried whey
   8.2 Caseins and caseinates
   8.3 Cheese
   8.4 Whey cheese
9 Procedure
   9.1 Preparation of the copperized cadmium column
   9.2 Checking the reducing capacity of the column
   9.3 Regeneration of the column
   9.4 Preparation of test portion
   9.5 Extraction and deproteination
   9.6 Reduction of nitrate to nitrite
   9.7 Blank test
   9.8 Determination
   9.9 Preparation of calibration graph
10 Calculation and expression of results
   10.1 Nitrite content
   10.2 Nitrate content
11 Precision
   11.1 General
   11.2 Repeatability
12 Test report
Bibliography

ISO 14673-1|IDF 189-1:2004 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.