速差动力学分析法同时测量钆-镝混合物中的单一稀土

Differential Kinetics Analysis for Simultaneous Determination of Gadolinium and Dysprosium in a Mixture

本文研究了稀土与新稀土显色剂DBC偶氮胂络合反应的动力学行为。稀土与试剂反应速率常数随着原子序数的增加而减小,发现了稀土动力学特性中的"钆断"现象。推导了钆、镝的动力学方程,提出了同时测量钆、镝二元混合物的速差动力学分析方法。测量了钆、镝相对浓度比为1:10-10:1的混合物试样,最低可测浓度为10^(-7)M,最大测量误差为13.5%。

We have studied the kinetics of the complex formation reaction between rare earths and dibromochloroarsenazo,and presented a differential kinetic method for simultaneous determination of gadolinium and dysprosium in a mixture.The reaction rate constants of rare earths decrease with increasing their atomic numbers.A"Gd broken"phenomenon was found for the first time.The kinetics equations of Gd and Dy were deduced,and that the active energies of Gd and Dy are 29.216 kJ and 53.35 kJ respectively was reported.Linear regression and graphical extrapolation appraochs have been applied to treatment of the kinetic analysis data.The comprision of the two methods shows that linear regression appraoch is better for the Gc^(3+)/Dy^(3+)-Dibromochloroarsenazo syslem,which has been used to determine Gd and Dy in a synthetical n ixture sample down to 10^(-7)M with accuracy of 0 to 13.5%.