title: Concentration, separation and determination of scandium, zirconium, hafnium and thorium with a silica-based sulphonic acid cation-exchanger.
abstract: A study has been made of the dependence of the sorption of scandium, zirconium, hafnium and thorium from aqueous solutions with a silica-based sulphonic cation-exchanger (SCE-SiO(2)) on the concentration and nature of the acid medium, time of contact, concentration of the element, and the ionic strength. The selectivity decreases in the order Zr approximately Hf > Th > Sc > Fe(III). The sorption characteristics of silica gel and SCE-SiO(2) have been compared, and the sorption mechanism is discussed. The SCE-SiO(2) exchanger has been used for 100-fold concentration of scandium, zirconium, hafnium and thorium from their 10(-8)-10(-7) M solutions, and a spectrophotometric method has been developed for their determination with a detection limit of 0.5 ng/ml for Zr and Sc and 0.1 ng/ml for Hf and Th. Zirconium and hafnium have been determined in the solvent phase by X-ray fluorescence and atomic-emission methods.
authors.affiliation: Department of Chemistry, N. V. Lomonosov State University, Moscow 119899, USSR.
authors.forename: I P
authors.initials: IP
authors.lastname: Alimarin
authors.forename: V I
authors.initials: VI
authors.lastname: Fadeeva
authors.forename: G V
authors.initials: GV
authors.lastname: Kudryavtsev
authors.forename: I M
authors.initials: IM
authors.lastname: Loskutova
authors.forename: T I
authors.initials: TI
authors.lastname: Tikhomirova