Methods for chemical analysis of iron,steel and alloy; The anion-exchange separation-pyrogallol photometric method for the determination of tantalum content
1 Principle
Tantalum and pyrogallol generate yellow complex compound in acid solution, which can be interfered by iron, titanium, niobium, molybdenum, wolfram, etc. which can be separated from tantalum with anion-exchange separation method.
Concentration and absorbance are proportionate when the tantalum content in 50ml solution is 50~800μg.
2 Reagents
2.1 Potassium pyrosulfate (solid), crushed into 3~4 mm pieces.
2.2 Hydrochloric acid (proportion: 1.19).
2.3 Hydrochloric acid (1+11).
2.4 Nitric acid (proportion 1.42).
2.5 Hydrofluoric acid (proportion 1.15).
