title: Cloud point extraction: an alternative to traditional liquid-liquid extraction for lanthanides(III) separation.
abstract: Cloud point extraction (CPE) was used to extract and separate lanthanum(III) and gadolinium(III) nitrate from an aqueous solution. The methodology used is based on the formation of lanthanide(III)-8-hydroxyquinoline (8-HQ) complexes soluble in a micellar phase of non-ionic surfactant. The lanthanide(III) complexes are then extracted into the surfactant-rich phase at a temperature above the cloud point temperature (CPT). The structure of the non-ionic surfactant, and the chelating agent-metal molar ratio are identified as factors determining the extraction efficiency and selectivity. In an aqueous solution containing equimolar concentrations of La(III) and Gd(III), extraction efficiency for Gd(III) can reach 96% with a Gd(III)/La(III) selectivity higher than 30 using Triton X-114. Under those conditions, a Gd(III) decontamination factor of 50 is obtained.
authors.affiliation: Conservatoire National des Arts et Métiers, Laboratoires de Chimie Organique & et des Sciences Nucléaires (CNRS ESA 7084), 292 rue St Martin, 75003 Paris, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Favre-Réguillon
authors.forename: Micheline
authors.initials: M
authors.lastname: Draye
authors.forename: Gérard
authors.initials: G
authors.lastname: Lebuzit
authors.forename: Sylvie
authors.initials: S
authors.lastname: Thomas
authors.forename: Jacques
authors.initials: J
authors.lastname: Foos
authors.forename: Gérard
authors.initials: G
authors.lastname: Cote
authors.forename: Alain
authors.initials: A
authors.lastname: Guy