Sorption Behavior of Metal Ions on Thiourea-Impregnated Silica Gel G and Alumina Stationary Phases in Aqueous HCI and Acetone-HCI Media: Quantitative Separation of Pb2+ and Hg2+ from Other Metal Ions

摘要

The sorption behavior of a number of metal ions was investigated on thiourea-impregnated silica gel G and alumina layers with aqueous HCI and acetone-HCI mobile phases. The mobility of the metal ions was examined under varying experimental conditions of mobile phase pH, effect of concentration of thiourea as the impregnant, and also the effect of solvent composition in acetone-HCI mixtures. The migration of metal ions depends on the solubility of metal salt, adsorption and precipitation of the ions in the network of the adsorbent. On impregnated silica gel G layers, for many ions, maximum adsorption occurs at pH 2 and above. 0.1 m and 0.2 m thiourea-impregnated alumina layers were found the most suitable for metal ion separations. For some metal ions, comparative study was made with thiourea and urea as the impregnant. Quantitative separations of Pb2+ and Hg2+ from some other metal ions and synthetic alloys were also carried out.