FLUORESCENCE ENHANCEMENT OF RARE-EARTHS BY YTTRIUM AND ITS APPLICATION

A study of the enhancement effect on the fluorescence intensity of the Eu3+-thenoyltrifluoroacetone (TTA)-cetyltri-methylammonium bromide (CTMAB) and the Dy3+ pyrocatechol-3,5-disulphonic acid (Tiron) systems by Y3+ has been carried out. In the presence of yttrium the fluorescence intensity of the systems was enhanced by a factor of about 100 and 15, respectively. The fluorescence intensity was a linear function of the concentration of europium or dysprosium in the range 1.0 x 10-(10)-1.0 x 10(-8) mol dm(-3) and 8.0 x 10(-8)-9.0 x 10(-6) mol dm(-3), respectively. The detection limit was 1.0x 10(-11) mol dm(-3) and 1.0x 10(-10) mol dm(-3), respectively. The standard addition method was used for the determination of europium or dysprosium in rare earth oxides and gave satisfactory results. The mechanism of enhanced fluorescence was proposed.