铬(Ⅵ)-Rh6G-溴酸钾体系催化动力学荧光法测定痕量铬

Determination of trace chromium by a catalytic spectrofluorimetry with Cr(Ⅵ)-Rh6G-KBrO_3 system

在醋酸-醋酸钠缓冲溶液中,铬（Ⅵ）催化溴酸钾氧化罗丹明6G（Rh6G）使其荧光强度减弱,据此建立一种催化动力学光度法测定环境水中铬（Ⅵ）的新方法。优化了反应和测定条件。该反应体系中Rh6G的最大发射波长λmax=555 nm。荧光值改变值与铬（Ⅵ）的浓度在0.01～0.14μg/mL范围内呈良好线性关系,检出限为3.46 ng/mL,相对标准偏差〈4.96%,加标回收率为95.5%～102.9%。

In HAc-NaAc buffer medium,Rh6G was oxidized by potassium bromate with chromium（ Ⅵ）as an catalyst,which resulting in fluorescence intensity decreased. A new catalytic kinetics spectrofluorimetry for determination of trace chromium was established and the optimum conditions were studied. Maximum emission peak of the reaction system located at 555 nm,the decreased fluorescence intensity was proportional to the concentration of Cr（ Ⅵ） in the range of 0. 01 ～ 0. 14 μg /mL. The detection limit was3. 46 ng /mL,RSD was less than 4. 96%,and the recoveries were 95. 5% ～ 102. 9%.