一种新的共发光体系──铽－钆（钪）－均苯四甲酸体系的研究和应用

STUDY OF A NEW FLUORESCENCE ENHANCEMENT SYSTEM TERBIUM-1, 2, 4, 5-BENZENE TETRACARBONIC ACID AND ITS APPLICATIONS

本文研究发现铽与均苯四甲酸有强烈的荧光反应，并观察到钆（钪）存在下的共发光现象，研究了该反应的荧光特点和影响因素，确定了反应和测定的最佳条件。钆和钪的引入使原有的铽－均苯四甲酸体系的荧光分别增加了２４０和９５倍。在最佳条件下，对应于钆和钪，铽的浓度分别在５．０×１０－８～３．０×１０－５ｍｏｌ／Ｌ和７．０×１０－８～１．０×１０－５ｍｏｌ／Ｌ的范围内与荧光强度成线性关系，检测限分别为２．０×１０－１０和５．０×１０－１０ｍｏｌ／Ｌ采用多点增量标准加入法测定了合成样品和包头稀土样品中的铽。回收试验的回收率为１００．１±０．０１％和９９．１±０．０３％。

A fluorescence enhancement phenomenon on adding Gd3+ (or Sc3+ ) to the terbium-1, 2, 4, 5-benzene tetracarbonic acid (BTCA) system was observed and studied in detail.The fluoresence intensities of these systems were 240 times and 95 times greater than those of the systems without gadolinium and scanium. The optimum concentrations were 4. 0 ×10-4mol/L for Gd3+ and 3.0 ×10-4mol/L for Gd and Sc respectively. The optimum pH values were 6. 3 and 6. 5,respectively. The fluorescence intensity was a linear function of the concentration of terbium in the range of 5.0 ×10-8mol/L-3. 0 ×10-5mol/L for system Tb-Gd-BTCA and 7. 0 ×10-8mol/L-1. 0 ×10-5mol/L for system Tb-Sc-BTCA. The detection limits were 2. 0 ×10-10 and 5.0 ×1010 mol/L terbium, respectively. These were used for the determinations of trance amount of terbium in rare earth samples with satisfactory.