1988 Volume 4 Issue 2 Pages 139-142
The equilibrium extraction behavior of a series of representative tervalent lanthanide ion, Pr, Eu and Yb, using 5, 7-dibromo-8-quinolinol (DBQ) as a chelating extractant, either alone or in combination with 4, 4′-(5-nonyl)-2, 2′-dipyridylamine (NDPA) as an adductant has been studied. The stoichiometry, extraction constants, and separation factors were determined. The results demonstrate that lanthanides are extracted as simple chelates, LnQ3, at lower HQ concentrations, or as self-adduct chelates, LnQ3•HQ, at higher HQ concentrations. In the presence of NDPA, mixed ligand chelates of either the type LnQ3•NDPA or LnQ2(HA)•NDPA (were HA- is the hydrogensuccinate ion) have been observed.