镝—镧—邻氟苯甲酸—乙二胺体系荧光增敏效应

STUDY OF FLUORESCENCEENHANCEMENT EFFECT OFDYSPROSIUM LANTHANUM o FBA EDA SYSYTEM

研究发现镝与邻氟苯甲酸（ｏ－ＦＢＡ）有较强的荧光反应，并观察到镧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．镧的加入使原有的镝—邻氟苯甲酸—乙二胺体系的荧光强度增大了８５倍．在最佳条件下，浓度在５．０×１０－６～５．０×１０－５ｍｏｌ·Ｌ－１范围内与荧光强度成线性关系，检测限为１．０×１０－６ｍｏｌ·Ｌ－１．采用多点增量标准加入法测定了合成稀土样品中镝的含量．

A fluorescence enhancement phenomenon on adding La 3+ ,Lu 3+ ,Y 3+ and Gd 3+ to the Dysprosium o FBA EDA system was observed and studied in detail.The fluorescence intensity of the system Dy 3+ ～La 3+ o FBA～EDA was 85 times greater than that of the system without La 3+ .The optimum concentrations of La 3+ , o FBA and EDA were 6.0×10 -4 mol·L -1 ,3.0×10 -3 mol·L -1 and 0.05%(v/v)respectively.The optimum pH value was 8.9.The fluorescence intensity was a line function of the concentration of Dy 3+ in the range of 5.0×10 -6 ～5.0×10 -5 mol·L -1 .The detection limits was 1.0×10 -6 mol·L -1 .The system has been used for the determination of Dy 3+ in the rare earth samples with satisfactory result.