罗丹明S-高碘酸钾体系催化光度法测定痕量铑

Catalytic Spectrophotometry Determination of Trace Rhodium(Ⅲ) with Rhodamine S-KIO₄ System

摘要: 研究了铑(Ⅲ)催化高碘酸钾氧化罗丹明S的褪色反应,据此建立了测定微量铑的催化光度分析法,研究了该催化氧化还原褪色反应的最佳条件及动力学参数.结果表明:在以硫酸为介质及90±0.5℃的条件下,罗丹明S-高碘酸钾体系测定微量铑的方法具有较高的灵敏度,线性范围为10~140μg/LRh(Ⅲ),检出限为5.0×10^-9g/mL,表观活化能为64.86 kJ/mol.方法灵敏,准确,应用于合成样品中微量铑的测定,结果令人满意.

Abstract: Based on the catalytic effects of rhodium(Ⅲ) on the colour fading reactions of Rhodamine S by oxidizing with KIO₄,a new catalytic spectrophotometric method for the determination of rhodium(Ⅲ) has been developed.The optimum condition and kinetic parameters of this reaction was studied in detail.The results show that in sulphuric acid medium and at 90±0.5℃,the method has higher sensitivity,the linear range of the determination was 10~140 μg/L,the detection limit was 5.0×10^-9 g/mL,and the apparent activation energy of catalytic reaction was 64.86 kJ/mol.The method has been applied to the determination of Rhodium in its composite samples with satisfactory results.