表面活性剂增敏偶氮氯膦mA褪色光度法测定铬的研究

The Spectrophotometric Determination of Trace Chromium(VI) with CPA-mA

研究了偶氮氯膦mA与铬 (VI)褪色反应的影响因素。发现在硝酸介质中 ,表面活性剂对偶氮氯膦mA与铬(VI)的褪色反应有明显的增敏作用 ;铬 (VI)量在 0～ 2 4 0 μg/L之间符合比尔定律 ,其摩尔吸光系数达到 8.2× 10 4L·mol-1·cm-1;建立了光度法测定铬的新方法。

The fading reaction of CPA-mA with Cr 2O 2- 7 was studied.In the medium of surface active agent and nitric acid,the fading reaction has high sensibility.The Beer's law is obeyed in the range of 0～240?μg/L Cr(VI) content, and the molar absorptivity of reaction is 8.2×10 4?L·mol -1 ·cm -1 .So a new method determining trace chromium is developed.This method can be used to the determination of chromium in water and alloy steel samples.