Evaluation of synergism in dispersive liquid-liquid microextraction for simultaneous preconcentration of some lanthanoids

A novel description has been developed on evaluation of synergism in dispersive liquid-liquid microextraction technique for simultaneous preconcentration of samarium, europium, gadolinium, and dysprosium ions. Dispersive liquid-liquid microextraction is a modified solvent extraction method and its acceptor-to-donor phase ratio is greatly reduced compared with other methods. The synergistic effects of 1-(2-pyridylazo)-2-naphthol and 1-hydroxy-2, 5-pyrrolidinedione as ligand and ionic liquids and organic solvents as extraction solvent have been investigated. The values of the synergistic coefficients of lanthanoids were calculated. The synergistic coefficients of -0.256, -0.184, -0.135, and -0.279 have been obtained for samarium, europium, gadolinium, and dysprosium ions, respectively. The results showed that in the presence of mixture of extraction solvent the synergistic effects are more than mixture of ligands in the dispersive liquid-liquid microextraction technique. (C) 2009 Elsevier By. All rights reserved.