Determination of Trace Chromium(ⅳ) by Catalytic Kinetic-Spectrophotometry

In this paper, a new kinetic spectrophotometric method for the determination of trace amounts of chromium was introduced. It was based on the fact that the Cr(ⅳ) could catalyze the discoloration of alizarin red dyeing oxidized by Potassium-periodate and sodium oxalate as the activator in HAc-NaAc medium. The optimum conditions influencing the rate of the reaction were examined. The method was sensitive, simple and selective. The linear range of the determination was 0-40 μg/L. The detection limit was 2.0×10-6 g/L. This method was used in the determination of trace Chromium(ⅳ) in the synthetic reaction solutions and the polluted water with satisfactory results.