3 - AS/NZS 1050.30:1994 METHODS FOR THE ANALYSIS OF IRON AND STEEL - DETERMINATION OF BORON CONTENT - CURCUMIN SPECTROPHOTOMETRIC
4 - PREFACE
5 - CONTENTS
7 - 1 Scope
7 - 2 Normative references
7 - 3 Principle
7 - 4 Reagents
7 - 4.1 Pure iron
7 - 4.2 Sodium hypophosphite monohydrate.
7 - 4.3 Hydrochloric acid
7 - 4.4 Nitric acid.
7 - 4.5 Sulfuric acid
7 - 4.6 Orthophosphoric acid
7 - 4.7 Acetic acid
8 - 4.8 Mixture of acetic and sulfuric acids.
8 - 4.9 Acetic buffer solution.
8 - 4.10 Sodium fluoride
8 - 4.11 Boron
8 - 4.12 Curcumin
8 - 5 Apparatus
8 - 5.1 Quartz beakers with quartz covers
8 - 5.2 Polypropylene or polytetrafluoroethylene volumetric flasks
8 - 5.3 Polypropylene or polytetrafluoroethylene bottle
8 - 5.4 Aluminium alloy block
8 - 5.5 Spectrophotometer
8 - 6 Sampling
8 - 7 Procedure
8 - 7.1 Test portion
9 - 7.2 Blank test 7.3.2 Formation of the coloured complex
9 - 7.2 Blank test
9 - 7.3 Determination
9 - 7.3.1 Preparation of the test solution
9 - 7.3.2 Formation of the coloured complex
9 - 7.3.3 Preparation of the compensating solution
9 - 7.3.4 Spectrophotometric measurements
10 - 7.4 Establishment of the calibration graph
10 - 7.4.1 Preparation of calibration solutions
10 - 7.4.2 Spectrophotometric measurements
10 - 7.4.3 Plotting the calibration graph
10 - 8 Expression of results
10 - 8.1 Calculation of the net absorbance
10 - 8.2 Calculation of the boron content
11 - 8.3 Precision
11 - 9 Test report
12 - Annex A - Examples of aluminium alloy blocks
14 - Annex B - Additional information on the international co-operative tests
15 - Annex C - Graphical representation of precision data
16 - Annex D - Additional precision tests conducted by European countries