Spectrophotometric determination of cobalt in hydrofining catalysts, alloys and salts with biacetylmonoxime 2-pyridylhydrazone

Abstract

Biacetylmonoxime 2-pyridylhydrazone (BMPH) has been examined to evaluate its usefulness as a selective spectrophotometric reagent for cobalt. The yellow coloration is formed at an initial pH of 5–6 in a medium containing 20% of dimethylformamide and measured at 430 nm at a final concentration of 0.5 N perchloric acid. The molar absorptivity is 3700 l mol^–1 cm^–1. The method has been applied to the determination of cobalt in synthetic mixtures, hydrofining catalysts, alloys and chemicals with good results. The BMPH chromogen shows a wide range of application.