甲苯胺蓝-高碘酸钾催化光度法测定铱  

Catalytic spectrophotometric determination of iridium with toluidine blue-KIO_4 system

作　　者：侯能邦[1] 陈吉书[1] 李祖碧[2] 曹秋娥[3] 

机构地区：[1]曲靖师范学院化学系,曲靖655000 [2]云南大学成人教育学院,昆明650091 [3]云南大学化学系

出　　处：《分析试验室》2003年第1期51-53,共3页Chinese Journal of Analysis Laboratory

摘　　要：在稀硫酸介质和加热条件下 ,铱对高碘酸钾氧化甲苯胺蓝 (TB)有明显的催化作用 ,以此反应为基础建立一个测定铱的催化光度法。方法对铱 (Ⅳ )测定的线性范围为 0～ 0 1 6μg mL ,检出限为 6 89× 1 0 -6mg mL。对 2 0 μgIr(Ⅳ )测定的相对标准偏差为 1 4% (n =1 1 )。催化反应对Ir(Ⅳ )和甲苯胺蓝均为一级反应 ,催化反应的表观活化能为 1 0 3 34kJ mol。考察了 40多种共存离子的影响 ,大多数常见离子不干扰。本法用于某些冶金产品及岩矿中铱测定的相对标准偏差为 0 47%～ 2 3% ,标准加入回收率为 98 8%～ 1 0 2 3%。A catalytic spectrophtometric method was developed for the determination of Ir(Ⅳ) based on its catalytic effects on the oxidation of toluidine blue(TB) by KIO 4 in the H 2SO 4 medium at 90 ℃. The linear range for the determination of Ir(Ⅳ) was 0～0.16 μg/mL with detection limit of 6.89×10 -6 mg/mL. The relative standard deviation for 11 replicate determinations of 2.0 μg of Ir(Ⅳ) was calculated to be 1.4%. The catalytic reactions was first-order for both Ir(Ⅳ) and TB, and the apparent activation energy of this catalytic reactions was found to be 109.34 kJ/mol. Most of the common foreign ions did not interfere in the determination. The method was applied for the determination of iroium in the metallurgy product and ore samples with the relative standard deviation over 0.47%～2.3% and the recovery over 98.8%～102.3%.

关 键 词：铱 高碘酸钾 甲苯胺蓝 动力学光度法 

分 类 号：O657.32[理学—分析化学]