催化动力学光度法测定痕量的铬(VI)

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

基于醋酸介质中,草酸钠作活化剂,铬(VI)对过碘酸钾氧化茜素红而使其褪色的反应的催化作用,建立了测定痕量铬(VI)的动力学光度法,讨论了其动力学条件。方法简便,灵敏,选择性好。测定铬(VI)的线形范围为0～40μg/L,检出限为2 0μg/L,用于合成水样和污水中痕量铬(VI)的测定,结果令人满意。

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.