H_2O_2-天青Ⅱ催化动力学光度法测定痕量铜(Ⅱ)  

Determination of trace copper(Ⅱ) by H_2O_2-azure(Ⅱ) catalytic kinetic spectrophotometry

作　　者：王洪福[1] 苏智先[1] 张素兰[1] 何黎明[1] 李春蓉[1] 

机构地区：[1]绵阳师范学院化学与化学工程系,绵阳621000

出　　处：《分析试验室》2008年第12期115-118,共4页Chinese Journal of Analysis Laboratory

摘　　要：在氨水介质中及加热条件下，痕量铜（Ⅱ）对H2O2氧化天青Ⅱ的褪色反应具有强烈的催化作用。探讨了最佳实验条件，据此建立了催化动力学光度法测定痕量铜（Ⅱ）的新方法。在选定的实验条件下，非催化反应与催化反应的吸光度差值△A与铜（Ⅱ）离子的质量浓度在16～56ug/L范围内有良好的线性关系，检出限为9．36×10^-11g／mL。并且测定了催化反应的动力学参数，反应为准一级反应.在75℃下的表观速率常数为K’=4．04×10^-3s^-1，表观活化能为74．54kJ／mol。方法用于人发中痕量铜（Ⅱ）的测定，回收率在99．7％-100．0％之间。In this work, the depigmentation reaction copper （ Ⅱ ） in NH3·H2O under heated condition. method for determining trace copper （ Ⅱ ） by catalytic enon. Under chosen experimental conditions, △A of H2O2 oxidizing azure （ Ⅱ ） can be greatly catalyzed by trace The optimal experimental conditions were discussed and a new kinetic speetrophotometry was established based on this phenomremains good linear relationship with mass concentration of copper （ Ⅱ ） within 16 - 56 ug/L, and the detection limit is 9.36 × 10^-11g/mL. The dynamic parameter is also measured, and the results show this reaction matches pseudo first order reaction. At 75 ℃, the apparent rate constant is K＇ =4.04 × 10^-3 s^-1, and apparent activation energy is 74. 54 kJ/mol. This method has good selectivity and high sensitivity, and can be used in the determination of trace copper （ Ⅱ ） in human hair with recoveries between 98.5 % and 101.5%. Compared with AAS method, this method gives more satisfactory results.

关 键 词：天青Ⅱ H2O2 催化动力学分光光度法 Cu(Ⅱ) 

分 类 号：O657.32[理学—分析化学]