计算光度法同时测定镧、铈、镨、钕

Simultaneous Determination of La^(3+) ,Ce^(3+) ,Pr^(3+) and Nd^(3+) in Their Mixtures by Computational Spectrophotometry

以二溴一氯 -偶氮氯膦 (DBC- CPA)为显色剂 ,并且在显色体系中加入不同量的 EDTA- Na2 P2 O7作为竞争配位剂 ,使得 4组分轻稀土组分间吸收光谱灵敏度的差别加大 ,从而增加了轻稀土混合物体系组分间吸收光谱的线性独立性。采用数值稳定性强的约束优化算法 -可变容差法处理光谱数据 ,对不同浓度比例的 4组分轻稀土混合物体系 (La3 +、Ce3 +、Pr3 +、Nd3 + )的测定 ,取得了较为满意的结果。

Since the spectra of the rare earth color complexes are rather similar,it is very difficult to simultaneously determine rare earth elements in their mixtures.To reduce the collinearity of multicomponent spectra,EDTA Na 2P 2O 7 were added to the rare earth 2 (4 chloro 2 phosphonophenylazo) 7 (2,6 dibromo 4 chlorophenylazo) 1,8 dihydroxy 3,6 naphthalene difulfonic acid(DBC CPA)color system.The flexible tolerance method which has high numerical stability and resolving power was used to improve the reliability of simultaneous spectrophotometry.The method has been applied to simultaneous spectrophotometric determination of four components of rare earth elements(La 3+ ,Ce 3+ ,Pr 3+ ,Nd 3+ )in synthetic samples with satisfactory results.