title: Solvent extraction of Cd(II) with N-cyclohexyl-N-nitrosohydroxylamine and 4-methylpyridine into methyl isobutyl ketone.
abstract: The distribution equilibria of the complexes cadmium-cnha and cadmium-cnha-4-methylpyridine in the water-methyl isobutyl ketone system have been studied at 25 degrees , by using (109)Cd as a radiotracer to measure the metal distribution ratio. A very sensitive method for detection of (109)Cd, based on the use of a liquid scintillator, has been developed. From the graphical treatment of the equilibrium data, it has been deduced that CdL(2) is the complex extracted in the absence of 4-methylpyridine, and that the adduct CdL(2)B is extracted when the second ligand is present. This model has been checked by treating the data with the program LETAGROP-DISTR and the following equilibrium constants have been obtained: stability constants of CdL(2), log beta(1) = 2.82 +/- 0.14, log beta(2) = 5.981 +/- 0.004; distribution constant of CdL(2), log K(DC) = -0.49 +/- 0.01; adduct formation constant of CdL(2)B, log K(s) = 2.70 +/- 0.07.
authors.affiliation: Department of Analytical Chemistry, University of Barcelona, Barcelona, Spain.
authors.forename: G
authors.initials: G
authors.lastname: Rauret
authors.forename: L
authors.initials: L
authors.lastname: Pineda
authors.forename: R
authors.initials: R
authors.lastname: Casas
authors.forename: R
authors.initials: R
authors.lastname: Compaño
authors.forename: A
authors.initials: A
authors.lastname: Sanchez-Reyes