title: Thin-layer chromatographic behavior and separation of alkaline earth metals on silica gel in aqueous sodium perchlorate solution.
abstract: The thin-layer chromatographic behavior of alkaline earth metal ions (Mg2+, Ca2+, Sr2+, and Ba2+) in aqueous sodium perchlorate solutions on silica gel thin-layers impregnated with sodium hydroxide has been surveyed as a function of salt concentration. At salt concentrations above 2 mol 1(-1), the selectivity of the metals increased with a decrease in the crystal ionic radii; with further increases in salt concentration, the selectivity differences among the metals expanded remarkably. In the present systems, it was supposed that the cation exchange, the surface complexation, and the salting-out effect participate simultaneously in the adsorption of the metals on silica gel. Typical chromatograms for the mutual separation of the alkaline earth metals are presented.
authors.affiliation: Laboratory of Chemistry, Nippon Medical School, 2-297-2, Kosugicho, Nakahara-ku, Kawasaki, Kanagawa 211-0063, Japan. yoichi@nms.ac.jp
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Takeda
authors.forename: Koji
authors.initials: K
authors.lastname: Ishida
authors.forename: Tadashi
authors.initials: T
authors.lastname: Hasegawa
authors.forename: Akira
authors.initials: A
authors.lastname: Katoh
mesh_terms: D000327:Adsorption; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D008673:Metals, Alkaline Earth / Q000737:chemistry* / Q000302:isolation & purification; D010472:Perchlorates; D058428:Silica Gel; D012822:Silicon Dioxide / Q000737:chemistry*; D012972:Sodium Hydroxide; D012996:Solutions; D014867:Water
chemical_list: D008673:Metals, Alkaline Earth; D010472:Perchlorates; D012996:Solutions; D014867:Water; D012972:Sodium Hydroxide; D058428:Silica Gel; D012822:Silicon Dioxide