1 Subject Content and Application Scope
This standard specifies the determination of aluminium oxide content by chromazurol S spectrophotometric method.
This standard is applicable to the determination of aluminium oxide content in limestone products for chemical industry and the determination range is 0.01%~1%.
2 Normative References
GB 6682 Water for Analytical Laboratory Use - Specification and Test Methods
GB/T 9721 Chemical Reagent - General Rules for the Molecular Absorption Spectrophotometry (Ultraviolet and Visible)
3 Method Summary
Melt the specimen with mixed flux of sodium carbonate - boric acid, leach with hydrochloric acid, mask iron with ascorbic acid and mask titanium with benzoglycolic acid; in the buffer system of acetic acid - sodium acetate, aluminium reacts with chromazurol S and surface active agent and generates fuchsia ternary complex; then, measure the absorbance at spectrophotometer wavelength of 560mn.
4 Reagents and Solutions
Water used in this standard shall conform to the specification of Grade 3 water specified in GB 6682; unless otherwise specified, the adopted reagents refer to analytical reagents.
4.1 Mixed flux: take two portions of anhydrous sodium carbonate (GB 639) and one portion of boric acid (GB 628), porphyrize them and mix well.
4.2 Sodium hydroxide (GB 629) solution: 200g/L, stored in plastic bottle.
4.3 Sodium hydroxide solution: 50g/L, stored in plastic bottle.
4.4 Hydrochloric acid (GB 622) solution: 1+1.
1 Subject Content and Application Scope
2 Normative References
3 Method Summary
4 Reagents and Solutions
5 Apparatus
6 Specimen
7 Analytical Procedures
8 Plotting of Working Curve
9 Expression of Analysis Results
10 Allowable Difference
Additional Information
