Fluorescence Enhancement of Rare Earths by Yttrium and its Application

Abstract
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 × 10−10–-1.0 × 10−8mol dm−3 and 8.0 × 10−8–-9.0 × 10−6mol dm−3, respectively. The detection limit was 1.0 × 10−11mol dm−3 and 1.0 × 10−10mol 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.