Table of Contents

1 -  AS 2300.1.2.1-1991 METHODS OF CHEMICAL AND PHYSICAL TESTING FOR THE DAIRYING INDUSTRY - GENERAL METHODS AND PRINCIPLES - DETE
1 -  PREFACE
1 -  FOREWORD
1 -  METHOD
1 -  1 SCOPE
2 -  2 REFERENCED DOCUMENTS
2 -  3 PRINCIPLE
2 -  4 REACTIONS
2 -  5 REAGENTS
2 -  5.1 General
2 -  5.2 Sulfuric acid,
2 -  5.3 Copper sulfate,
2 -  5.4 Potassium sulfate,
2 -  5.5 Hydrogen peroxide,
2 -  5.6 Sodium hydroxide,
2 -  5.7 Boric acid,
2 -  5.8 Sulfuric acid,
2 -  5.9 Mixed indicator
2 -  5.10 Tryptophan (C 11 H 12 N 2 O 2 )
2 -  5.11 Ammonium sulphate
2 -  6 APPARATUS
2 -  6.1 Blender(s),
2 -  6.2 Kjeldahl flasks,
2 -  6.3 Liebig condensers,
2 -  6.4 Splash-heads,
2 -  6.5 Erlenmeyer flasks,
2 -  6.6 Glass beads or anti-bumping granules
2 -  6.7 Heating device,
2 -  6.8 pH meter,
3 -  7 NITROGEN RECOVERY TESTS
3 -  7.1 General
3 -  7.2 Tryptophan recovery test
3 -  7.3 Ammonium sulfate recovery test
3 -  7.4 Corrective action
3 -  8 PREPARATION OF TEST SAMPLE
3 -  8.1 Liquid milks and cream
3 -  8.2 Dried milks, caseinates and coprecipitates
3 -  8.3 Ice cream and frozen milk products
4 -  8.4 Cheese
4 -  8.5 Sweetened condensed milk
4 -  8.6 Evaporated milk
4 -  8.7 Yogurt
4 -  8.8 Caseins
4 -  9 TEST PORTIONS
5 -  10 PROCEDURE
5 -  10.1 Blank test
5 -  10.2 Method
5 -  11 CALCULATION
5 -  12 PRECISION
6 -  12.1 Repeatability
6 -  12.2 Reproducibility
6 -  13 TEST REPORT
6 -  14 REFERENCES
7 -  APPENDIX A - MODIFIED KJELDAHL PROCEDURES
7 -  A1 SCOPE
7 -  A2 BLOCK DIGESTION APPARATUS
7 -  A3 STEAM DISTILLATION
7 -  A4 REDUCED TEST PORTION

Abstract

Sets out the reference Kjeldahl method for the
determination of nitrogen in milk, milk fractions and
milk products. The method allows for the estimation of
nitrogen on a mass/mass basis and a mass/volume basis.

Scope

This Standard sets out the reference Kjeldahl method for the determination of nitrogen in milk, milk fractions and milk products. The method allows for the estimation of nitrogen on a mass/mass basis and a mass/volume basis.
This method is applicable to test portions containing at least 2 mg of nitrogen. Nitrogen present as nitrate or nitrite is not determined.
NOTE: Information is given in Appendix A on the use of modified Kjeldahl systems which have been shown to provide results of similar precision to this reference method. These modifications may be used if validated.

General Product Information

Published
Document Type	Standard
Status	Current
Publisher	Standards Australia
Pages
ISBN
Committee	FT-024
Supersedes	AS 2300.1.2.1-1988 DR 86164