二溴羧基偶氮胂-H_2O_2体系催化光度法测定痕量铜的研究  

Catalytic spectrophotometric determination of trace copper (Ⅱ) with dibromocaboxyarsenazo-hydrogen peroxide system

作　　者：李北罡[1] 祁姣[1] 

机构地区：[1]内蒙古师范大学化学与环境科学学院,呼和浩特010022

出　　处：《分析试验室》2008年第10期49-51,共3页Chinese Journal of Analysis Laboratory

基　　金：内蒙古自治区自然科学基金(20040802137)项目资助

摘　　要：在H2SO4介质中,Cu（Ⅱ）对H2O2氧化二溴羧基偶氮胂褪色反应有显著的催化作用,据此建立了催化动力学光度法测定痕量Cu（Ⅱ）的新方法,并就反应体系的动力学性质进行了研究。结果表明,该催化反应为准零级反应,表观活化能为53.97 kJ/mol,表观速率常数为1.38×10^-4/s,方法的线性范围为0-0.032 mg/L,检出限为0.64μg/L,可直接用于土豆、黄豆、小红豆中痕量Cu（Ⅱ）的测定,回收率为95.0%-107.8%。In the medium of sulfuric acid, a new catalytic kinetic spectrophotometric method for the determination of trace copper has been developed based on the catalytic effect of trace Cu（ It ） on discoloring reaction of dibromocaboxyarsenazo （DBKKA） with Hydrogen peroxide. The optimum conditions and kinetic parameters of this reaction were studied. The results showed that the catalytic reaction was a quasi-zero-order reaction. The apparent rate constant and the activation energy of the reaction were 1.38 × 10^-4· s^-1 and 53.97 kJ/mol, respectively. The linear range of the determination was 0 - 0.032 mg/L, and the detection limit was 0.64μg/L for Cu（Ⅱ）. The method has been applied to the determination of trace copper in the foodstuffs with satisfactory results.

关 键 词：二溴羧基偶氮胂 Cu(Ⅱ) H2O2 催化光度法 

分 类 号：O657.32[理学—分析化学]