Methods for chemical analysis of iron, steel and alloy.The extraction seperation-The dimethylglyoxime spectrophotometric method for the determination of nickel content
Methods for chemical analysis of iron, steel and alloy—The extraction separation—
The dimethylglyoxime spectrophotometric method for the determination of nickel content
1 Subject content and applicable scope
This standard specifies the determination of nickel content by extraction separation-dimethylglyoxime spectrophotometric method.
This standard is applicable to the determination of low-content nickel in pig iron, carbon steel, alloy steel and precision alloy, with a measuring range of 0.010% to 0.50%.
2 Method summary
Dissolve the sample with acid, use ammonium citrate as the masking agent for iron, and add dimethylglyoxime to react with nickel to produce nickel dimethylglyoxime, which is extracted with chloroform, and then reextracted with dilute nitric acid in the aqueous phase, thus in the strong alkaline medium, with ammonium persulfate as oxidant, nickel and dimethylglyoxime will react to produce red complex, and its absorbance is measured.
The content of manganese in the pipetting solution is less than 25 mg, that of copper is less than 3.5 mg, and that of cobalt is less than 15 mg, without interfering with the determination.
3 Reagents
3.1 Chloroform.
3.2 Ethanol (>95%).
3.3 Perchloric acid (ρ 1.67 g/mL).
3.4 Ammonia (ρ 0.90 g/mL).
3.5 Ammonia (1+30).
3.6 Nitric acid (2+3).
3.7 Nitric acid (1+20).
Foreword i
1 Subject content and applicable scope
2 Method summary
3 Reagents
4 Analysis procedure
5 Calculation of analysis result
6 Precision
Annex A Precision test raw data
