甲苯胺蓝指示反应动力学光度法测定痕量钌

KINETIC PHOTOMETRIC DETERMINATION OF TRACE AMOUNTS OF RUTHENIUM INDICATED BY THE OXIDATION OF TOLUIDINE BLUE WITH POTASSIUM PERIODATE

在磷酸和热水浴中 ,钌 (Ⅲ )对高碘酸钾氧化甲苯胺蓝的反应具有催化作用 ,据此建立了测定钌的新催化光度法。钌在 0～ 0 .0 5 0 μg/ 2 5ml范围内与催化反应速率有良好的线性关系 ,检出限为 5 .5 3× 10 - 5μg·ml- 1。对 0 .0 30 μg/ 2 5ml钌 (Ⅲ )测定的相对标准偏差为 2 .0 % (n =11)。该催化反应对钌 (Ⅲ )和甲苯胺蓝分别为一级反应 ,其表观活化能为 5 0 .2 6kJ·mol- 1。试验了 4 0多种共存离子的影响 ,大多数的常见离子不干扰。该方法用于岩矿和冶金产品中钌的测定 ,相对标准偏差为 2 .1%～ 2 .4 % ,标准加入回收率为 10 0 .1%～ 10 5 .4 %。

A new catalytic photometric method for the determination of ruthenium based on its catalytic effect on the oxidation of toluidine blue (TB) by KIO 4 in H 3PO 4 medium was reported. A linear relationship was obtained between the reaction rate and the concentration of Ru(Ⅲ) in the range of 0～0.050μg/25ml. The detection limit was 5.53×10 -5 μg·ml -1 . The relative standard deviation for the determination of 0.030μg/25ml of Ru(Ⅲ) was 2 0% ( n =11). The catalytic reaction was found to be of first order for both Ru(Ⅲ) and TB with the appearent activation energy of 50.26kJ·mol -1 . Test for the interferences of more than 40 foreign ions showed that most of the common ions were tolerable. The method has been applied to the determination of trace amounts of ruthenium in some ores and metallurgical products giving RSD′s in the range of 2.1%～2.4% and recoveries in the range of 100 1%～105.4%.