Adsorption Studies of Heavy Metal Cations on Silica Flat Bed Induced with Microcrystalline Cellulose Gels: Quantitative Determination of Cobalt and Nickel by Optical Scanning Densitometry

Abstract

Silica gel H impregnated with microcrystalline cellulose gel in alkaline medium was used as a stationary phase for the thin layer chromatography of heavy metal cations. A mixture of 10% aqueous potassium thiocyanate and triton X-100 in 1:1 v/v has been identified as the best combination of mobile phase for achieving selective separation of cobalt from nickel. The efficacy of the chromatographic system has been investigated by monitoring reproducibility of R F values and spot compactness with respect to the change in sample concentration and matrix effect. The improved selectivity of impregnated silica gel H was expounded by SEM and FTIR studies. The typical surface modification as well as the chemical changes in impregnated silica gel H was attributed. Chromatograms of the cations were quantitatively evaluated by scanning densitometry in comparison with ICP elemental analysis. The proposed method is applied for the determination of cobalt and nickel cations in spiked samples of geological and industrial origin.