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Increased selectivity in ion-exchange planar electrochromatography. Electrochromatographic separation on cerium(IV) tungstate papers of amino acids from some synthetic mixtures and pharmaceutical products

Misra A. K., Pachauree S.

Acta Chromatographica

2002

No. 12

189-200

The electrochromatographic behaviour of amino acids has been studied on cerium(IV) tungstate-impregnated papers. Five background electrolytes of different pH were investigated at a fixed potential and for a fixed time. On the basis of the compounds' differential migration, which depends on the ion-exchange properties of the cerium(IV) tungstate and the nature of the complexes formed with the electrolytes, some useful binary and ternary separations of amino acids have been achieved. The separation of some acidic amino acids from the others present, that of DL-ß-phenyl-alanine from other phenyl (and other) amino acids, and the separation of DL-isoleucine from DL-norleucine are of special interest. L-Lysine and DL-methionine from seven pharmaceutical products have been separated and quantitatively analysed. The utility of this simple, inexpensive, and accurate method has been illustrated by the analysis of amino acids in pharma-ceutical products.

Retention behaviour of synthetic dyes on zirconium(IV) phosphoantimonate papers

Misra A. K., Pachauree S.

Acta Chromatographica

2001

No. 11

139-153

The chromatographic behaviour of 24 synthetic dyes has been studied on zirconium(IV) phosphoantimonate papers with ten pure and mixed mobile phases including tap water and five buffers of different pH. The effects of mobile phase composition, impregnation, and pH on RF values were studied. The movement of dyes is explained on the basis of ion exchange, adsorption, intermolecular hydrogen-bonding, and the solubility of the dyes in the mobile phases. Differences between RF values have enabled many analytically difficult binary and ternary separations.