title: Organic-solvent/water/ionic-liquid triphasic system for the fractional extraction of divalent metal cations.
abstract: A novel cyclohexane/water/ionic-liquid (1-butyl-3-methylimidazolium hexafluorophosphate, [bmim][PF6]) triphasic extraction system was studied for a possible fractional extraction of divalent metal cations with co-using 8-quinolinol (HQ) and tri-n-octylphosphine oxide (TOPO) as competitive extractants. In this system, Ni2+ was extracted into the [bmim][PF6] phase as a Q(-)-complex, whereas each of Mn2+, Zn2+, Cd2+ and Pb2+ was extracted into the cyclohexane phase as an ion-pair of a cationic TOPO-complex and PF6-. A suitable selection of extractants and ionic liquid can result in developing a powerful triphasic fractional extraction system.
authors.affiliation: Division of Material Chemistry, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa 920-1192, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Takata
authors.forename: Naoki
authors.initials: N
authors.lastname: Hirayama