Methods for chemical analysis of aluminium and aluminium alloys - Part 7：Determination of manganese content Potassium periodate spectrophotometric method
本部分规定了铝及铝合金中锰含量的测定方法。本部分适用于铝及铝合金中锰含量的测定。测定范围：0.004%~1.80%。本部分代替ＧＢ／Ｔ６９８７．７—２００１《铝及铝合金化学分析方法 高碘酸钾光度法测定锰量》。 本部分与ＧＢ／Ｔ６９８７．７—２００１相比主要变化如下： ———增加了“８．１重复性”； ———增加了“９ 质量保证与控制”条款。
1 Scope
This part specifies the determination of manganese content of aluminium and aluminium alloys.
This part is applicable to the determination of manganese content of aluminium and aluminium alloys. Determination scope: 0.004%~1.80%.
2 Method Summary
Dissolve specimen with sodium hydroxide, acidify with sulfuric acid and nitric acid, and oxidize and develop color with potassium periodate. Measure the absorbance at wave length 525nm of spectrophotometer.
3 Reagents
3.1 Sulfuric acid (ρ1.84 g/mL).
3.2 Nitric acid (ρ1.42 g/mL).
3.3 Phosphoric acid (ρ1.69 g/mL).
3.4 Hydrofluoric acid (ρ1.14 g/mL).
3.5 Sulfuric acid (1+1).
3.6 Caustic soda solution (200g/L).
3.7 Fluoroboric acid: put 800mL saturated boric acid solution under 20℃ and 200mL hydrofluoric acid (3.4) into plastic bottle, and mix uniformly.
3.8 Potassium periodate solution (50 g/L): weight 5g potassium periodate to dissolve in water, add 20mL nitric acid (3.2), dilute to 100mL with water, and mix uniformly.
3.9 Sodium nitrite solution (20 g/L).
3.10 Sodium sulfite solution (10g/L): dissolve 1g sodium sulfite in 100mL sulfuric acid (1 +20), and mix uniformly.
3.11 Water without reducer: add 10mL sulfuric acid (3.5) in one liter water to acidify and boil, add little potassium periodate, continue to boil about 10min for standby after cooling.
3.12 Standard manganese storage solution: weight 1.000g manganese into beaker, add 20mL sulfuric acid (3.5) and about 80mL water, boil 3min after dissolution, and then cool. Move into to 1000mL volumetric flask, dilute with water to scale, and mix uniformly. 1mL this solution contains 1mg manganese.
3.13 Standard manganese solution: move 50.00mL standard manganese storage solution (3.12) into 1000mL volumetric flask, dilute with water to scale, and mix uniformly. 1mL this solution contains 0.05mg manganese.
4 Instrument
Spectrophotometer.
Foreword I
1 Scope
2 Method Summary
3 Reagents
4 Instrument
5 Sample
6 Analytical Procedures
7 Calculation of Analytical Results
8 Precision
9 Quality Assurance and Control
Annex A (Informative) Comparison of Chapter and Article Numbers of this Part and ISO 886:1973
Annex B (Informative) Technical Difference of this Part and ISO 886:1973 and Reason
