Spectrophotometric determination of cobalt with cyclohexane-1, 2-dione bis(2-pyridylhydrazone)

Abstract

A method for the spectrophotometric determination of cobalt with cyclohexane-1,2-dione bis(2-pyridylhydrazone) is described. The pink complex is formed at an initial pH of 4–5 in a medium containing 12%V/V dimethylformamide, and the absorbance is measured at 525 nm at a final perchloric acid concentration of ca. 0.5 M. The molar absorbtivity is 13700 l mol^–1 cm^–1. The method has been applied to the determination of cobalt in alloys and minerals.