Catalytic kinetic spectrophotometry for the determination of cobalt in alloy steel

A new method for the determination of trace Co? in the medium of nitric acid was investigated.It was based on that Co? could catalyze the discoloring reaction of methyl violet oxidized by hydrogen peroxide.The detection limit for cobalt was 2.53×10~(-11) g/mL and the linear range of the determination was 10～135 μg/L.The method has been applied to determine Co? in alloy steels with satisfactory results.