摘要：

在pH=5.0的NaAc-HAc缓冲介质中,铬(Ⅵ)能催化过氧化氢氧化茜素红的褪色反应。据此,建立了催化光度法测定环境中痕量铬(Ⅵ)的新方法。在优化条件下,于最大吸收波长422 nm处进行测定,铬(Ⅵ)浓度在3.0×10^-7~1.0×10^-5mol/L范围内呈现良好的线性关系;检出限为1.8×10^-7mol/L(3σ);对1.0×10^-6 mol/L的铬(Ⅵ)进行了平行测定(n=11),其相对标准偏差为0.5%;考察了多种共存离子的影响。将此法应用于废水中铬(Ⅵ)的测定,回收率在96.5%~97.7%之间,结果满意。

关键词: 催化光度法, 铬(Ⅵ), 过氧化氢

Abstract:

A new catalytic spectrophotometry method for the determination of trace chromium (Ⅵ) has been developed. The method is based on the significant catalytic action of trace chromium(Ⅵ) on the oxidation of bromophevnol red by hydrogen peroxide in HAc-NaAc buffer solutions at pH is 5.0. Under the optimum conditions，the determination is carried out on the maximum absorptive wavelength 422 nm，and when the chromium(Ⅵ) concentration is in the range of 3.0×10^-7-1.0×10^-5 mol/L，a very good linear relationship occurs. Detection limit is 1.8×10^-7 mol/L.Parallel determination is carried out when the chromium (Ⅵ) concentration is 1.0×10^-6mol/L，its standard deviation is 0.5%. Many kinds of co-existing ions have been investigated. When this method is applied to the determination of chromium(Ⅵ) in wastewater，the recovery rate reaches 96.5%-97.7%，having very good effectiveness.

Key words: catalytic spectrophotometry, chromium (Ⅵ), hydrogen peroxide

中图分类号: 

• O657.39