Language：Japanese   Publisher：JAPAN SOC ANALYTICAL CHEMISTRY  

The adsorption behavior of all the rare earths, except for promethium, was surveyed on carboxymethyl cellulose thin layers in sodium nitrate solutions as a function of the concentration of salt. At lower salt concentrations, the R-f values of the lanthanoids showed an S-shaped variation with their atomic number, and yttrium lay near to lanthanum, relatively analogous to the adsorption behavior in chloride solutions. At higher salt concentrations, the behavior of the metals was considerably different from that in the chloride solutions, and the R-f values of the lanthanoids decreased with an increase of their atomic number. The R-f value of yttrium gradually approached that of europium with increasing salt concentration in nitrate media. Two-dimensional development appeared first with a 0.5 M sodium chloride solution and second with a 5 M sodium nitrate solution, allowing yttrium to be separated from all of the rare earths.

DOI： 10.2116/bunsekikagaku.53.1325

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Language：English   Publisher：ELSEVIER SCIENCE BV  

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 l(-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. (C) 2004 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.chroma.2004.07.064

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Language：Japanese   Publisher：JAPAN SOC ANALYTICAL CHEMISTRY  

The thin-layer chromatographic behavior of all rare earths, except for promethium on carboxymethyl cellulose in aqueous sodium chloride solutions, has been surveyed as a function of the concentration of the salt to develop a new system for the separation of rare earths. It is reasonable to suppose that the competitive cation exchange between the solvent cations and the rare earths, the surface complexation of the rare earths with the carboxymethyl groups, and the salting-out effect of the solvent used, and moreover a change in the inner sphere coordination numbers across the rare earth series, play important roles in determining the R-f values of the metals in the present system. Yttrium, which generally belongs to heavier rare earths, has been separated from all of the rare earths, except for lanthanum, which provides Rf values similar to those of yttrium.

DOI： 10.2116/bunsekikagaku.53.729

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DOI： 10.2116/bunsekikagaku.53.729

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DOI： 10.2116/bunsekikagaku.53.1325

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