EXTRACTION OF EU(III) AND GD(III) RADIOISOTOPES FROM NITRATE MEDIUM BY SYNERGISTIC MIXTURE OF THENOYLTRIFLUOROACETONE AND 15-CROWN-5 OR 18-CROWN-6 IN BENZENE

The effect of adding 15-crown-5 (15C5) or 18-crown-6 (18C6) = CE, for the extraction of Eu(III) or Gd(III) = M(3+), by thenoyltrifluoroacetone (HTTA) in benzene from a nitrate aqueous medium of constant ionic strength [0.2(H+, NaNO3)] was studied. The results indicated that the extraction is enhanced by adduct formation in the organic phase, the main extracted species formed being M(NO3)(TTA)(2)HTTA for the chelate and M(NO3)(TTA)(2) . CE for the adduct. The extraction and stability constants of these species were evaluated, The thermodynamic parameters for the extraction of both Eu and Gd with HTTA alone as well as with its mixture with each of the crown ethers, 15C5 and 18C6, were determined and discussed.