速差对数外推法同时分光光度测定铂和金及其与双波长法的比较

Differential Reaction Rate Logarithmic Extrapolation Method for Simultaneous Spectrophotometric Determination of Platinum and Gold in Mixtures and Comparison with Dual-Wavelength Methods

本文包括两部分,i)研究了铂(Ⅳ)和金(Ⅲ)分别与硫代米蚩酮(TMK)之间反应的动力学性质,发现金(Ⅲ)-TMK-乳化剂OP配合物立即生成,而铂(Ⅳ)-TMK-乳化剂OP体系缓慢形成,据此建立了以对数外推法同时测定混合物中铂和金的方法,也测定了(26℃时)慢反应者[铂(Ⅳ)]的速率常数(K=0.0496min^(-1)、半衰期(t_(1/2)=14.0min)和活化能(E=4.32×10~4J/mol)。ii)以对合成样和实际样分析为例。比较研究了上述反应速差法和两种双波长法,结果表明三种方法精密度及准确度皆好,其它方面各有优缺点。

The kinetic properties of reactions between platinum (Ⅳ) and gold (Ⅲ) with thio-Michler's ketone(TMK) respectively have been investigated. The results show that the gold(Ⅲ)-TMK-emulsifier OP complex is formed immediately, while platinum (Ⅳ)-TMK-emulsifier OP system shaped up slowly. Accordingly, a simultaneous determination of platinum and gold in mixtures by logarithmic extrapolation method has been developed. The rate constant, half-value period and activation energy of the slower reaction was determined also. Furthermore, comparative study on the above kinetic method and two kinds of dualwavelength methods was made by means of analysing synthetic or/and real samples. The results show that a(?) three methods are precise and accurate, but in other respects each has his own strong and weak points.