THIN-LAYER CHROMATOGRAPHIC BEHAVIOR AND SEPARATION OF RARE-EARTHS IN SILICA GEL-AQUEOUS ALKALI-METAL CHLORIDE SYSTEMS

The thin-layer chromatographic behaviour of all the rare earths except Pm on silica gel in aqueous solutions of five alkali metal chlorides has been surveyed. The Rf-values and the logarithms of the separation factors relative to Gd vary in a regular and peculiar way with increasing atomic number, through a reflection of the strong tetrad effect. A discussion concerning the effects on the Rf-values of the solvent cations and the solvent anions, and typical chromatograms for the separations of multi-component mixtures containing adjacent lanthanoids are also presented. © 1990 Springer-Verlag.