摘要
基于镧(铈)-三溴偶氮胂体系吸收光谱出现等色点的特征,推断络合反应为M+nL=ML_n。用线性回归法与一种新的最优化方法分别计算了两种络合物的组成、摩尔吸光系;数及表观稳定常数。在1.2mol/L的HCl介质中,La^(3+)、Ce^(3+)与三溴偶氮胂形成M:L=1:3络合物,logβ_3分别为15.36与15.68,ε630均为1.36×10~5L·mol^(-1)·cm^(-1)。
According to the appearance of isosbestic point in the absorption spectra of La/Ce-tribromoarsenazo(TBA)complexing systems, the complexation reaction is considered to be M+nL=ML_n. The linear regression method and a new optimization method are used for calculating the composition, the molar absorptivity, the apparent stability constant of the complex and the concentration of the complexing agent. In 1.2mo1/L HCl solution, La^3+ and Cc^3+ react with TBA to form 1:3 complexes, the molar absorptivity of both complexes (ε_(630))determined is 1.36×10~5 L·mol^(-l)·cm^(-l), and the apparent stability constants(10gβ_3) are 15.36 and 15.68, respectively, The method proposed is adaptable to such system where the accurate concentration of the complexing agent can not be known convenient’y.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
1991年第9期997-1001,共5页
Chinese Journal of Analytical Chemistry
关键词
镧
铈
三溴偶氮胂
络合物
稳定常数
Lanthanum
Cerium
Tribromoarsenazo
Stability constant
Linear regression
Optimization
