Determination of vanadium with hexamminecobalt(III) chloride

Abstract

Precipitation reactions of meta-, hexa-, and pyrovanadates with hexamminecobalt(III) chloride were studied in detail to find the optimum conditions for the gravimetric and radiometric determination of vanadium.
Recommended procedures for both gravimetric and radiometric analysis of vanadium are as follows. Neutral or acidic sample solution containing 530 mg of vanadium is adjusted to pH 13 by adding sodium hydroxide solution. After allowing to stand for 30 minutes, the excess reagent solution is added to the sample solution. The precipitate obtained is filtered and washed. The weight of the precipitate is measured after drying at 110°C. Radiometric determination is done under the same conditions but on microscale using radioactive cobalt compound.
The gravimetric method is applicable to the determination of milligram amounts of vanadium, while the radiometric method is useful for microgram amounts of vanadium.