摘要
在HCl介质和90℃加热条件下,铱(Ⅳ)对高碘酸钾氧化孔雀绿褪色反应有显著的催化作用,探讨了该催化反应的最佳优化条件,据此建立了催化动力学光度法测定痕量铱(Ⅳ)的新方法.在选定的实验条件下,非催化体系和催化体系的吸光度差值△A与铱(Ⅳ)的质量浓度在0.0-2.5μg.(25 mL)-1范围内呈线性关系,其检出限为7.63×10-10g.mL-1.测定了催化反应的动力学参数,该反应为准一级反应,反应的表观活化能为107.88 kJ.mol-1,在90℃下表观速率常数为7.45×10-4s-1.该方法简便快捷,灵敏度高,选择性好,用于分子筛催化剂和活性碳样品中铱的含量测定,其回收率在99.0%-108%之间,符合痕量分析的要求.
This paper discusses the catalytic kinetic spectro-photometric determination of trace iridium （IV）. The depigmentation reaction of potassium pefiodate oxidazing malachite green can be greatly catalyzed by iridium （IV） in HCI and 90℃ water condition. According to this phenomenon, a new method of catalytic kinetic photometric determination of trace iridium （IV） has been established. Absorbency difference △A and iridium （IV） mass concentration show a good linear relationship in 0.0-2.5 μg·（25 mL）^-1, and the detection limit is 7.63×10^-10g ·mL^-1. The dynamic parameters are also measured and show that this reaction matches pseudo first order reaction. The apparent activation energy is 107.88 kJ·mol^-1 and the apparent rate constant is 7.45 ·10^-4 s^-1. This method is of good selectivity and high sensitivity. It has been applied to the determination of iridium in molecular sieve, and got a recovery rate between 99.0% -108% , which meets the request of trace analysis.
出处
《四川师范大学学报（自然科学版）》
CAS
CSCD
北大核心
2009年第1期89-92,共4页
Journal of Sichuan Normal University（Natural Science）
基金
四川省教育厅自然科学重点研究基金(2006A113)资助项目
关键词
铱(Ⅳ)
孔雀绿
高碘酸钾
催化动力学光度法
Iridium （IV）
Malachite green
Potassium periodate
Catalytic kinetic photometry
