SORPTION-DESORPTION BEHAVIOR OF THE AMINO-ACIDS GLYCINE AND SERINE ON CHEMICALLY PRETREATED SILICA-GEL IN RELATION TO CHROMATOGRAPHY

Chemically pretreated (NaOH, KOH) silica gel samples of surface-phase pH 7.0-11.0 were prepared and parameters like surface area, Na and K ion-content and H+ ion-exchange capacity determined. The samples were employed for the sorption-desorption study of the amino acids glycine and serine from 90% ethanol solutions. The sorption was found to depend on pH of the substrate and the alkali used for the pretreatment. The process was fast and almost athermic. Desorption efficacy and retarding influence on adsorption by electrolytes was in the order: Th(NO3)4 > Al(NO3)3 > Mg(NO3)2 > NaNO2. The distribution coefficients for adsorption and desorption were employed in their column chromatography.