乙基罗丹明B-高碘酸盐催化光度法测定痕量钌

Catalytic Spectrophotometric Method for the Determination of Trace Ruthenium with Ethylrhodamine B and Periodate

在钌催化高碘酸盐氧化乙基罗丹明B(ERB)基础上提出了测定钌的动力学方法。测定钌的校正曲线范围为 0 2～ 1 5ng/2 5mL ,检出限低至 1 0 - 1 0 mol/LRu ,对 5,1 0 ,1 5ng/2 5mLRu 测定的相对标准偏差分别为6 60 ,3 2 0和 1 76% (n =1 1 )。反应对ERB ,Ru ,KIO4,H3PO4均为一级 ,在CIO4- CRu 条件下 ,观察到Michaelis类型的动力学 ,催化剂与高碘酸盐形成 1∶1络合物 ,表观活化能为 37 68kJ/mol。本法用于某些岩矿和冶金产品中钌的分析 ,RSD(n =8)为 1 92 %～ 2 56% ,标准加入回收率为 97 0 %～ 1 0 0 8%。

A kinetic method is proposed for the determination of ruthenium based on the catalytic effect of Ru(Ⅲ)on the reaction of ethylrhodamine B(ERB) with periodate. Calibration graphs for the determination of Ru in the range of 0.2-1.5ng/25mL were obtained. Its detection limit was reached down to 10 -10 mol/L level. The relative standard deviations for 11 replicate measurements of 5, 10 and 15 ng of Ru(Ⅲ) per 25mL were 6.60%, 3.20% and 1.76%, respectively. The reaction was first order with ERB, Ru(Ⅲ), KIO 4 and H 3PO 4 respectively. Under the condition of [Periodate][Ru(Ⅲ)], the Michaelis type kinetics was observed. The formation of 1:1 complex between the catalyst and periodate was suggested. The apparent activation energy of catalytic reaction was found to be 37.68 kJ mol -1 . The method was applied to the analysis of Ru in some ores and metallurgical products. The RSD(n=8)were 1.92%-2.56% and the range of recoveries was from 97.0%-100.8%.