A study of the enhancement effect on the fluorescence intensity of the
Eu3+-thenoyltrifluoroacetone (TTA)-cetyltri-methylammonium bromide (C
TMAB) and the Dy3+ pyrocatechol-3,5-disulphonic acid (Tiron) systems b
y Y3+ has been carried out. In the presence of yttrium the fluorescenc
e intensity of the systems was enhanced by a factor of about 100 and 1
5, respectively. The fluorescence intensity was a linear function of t
he 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), resp
ectively. 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 f
or the determination of europium or dysprosium in rare earth oxides an
d gave satisfactory results. The mechanism of enhanced fluorescence wa
s proposed.