Thin layer chromatographic separation of cobalt from nickel on impregnated silica gel layers: quantitative determination by digital image analysis

Abstract

Thin layer chromatography ( TLC) of cobalt and nickel has been performed on silica gel layers induced with alkali mediated cellulose extract. A novel combination of 10% aqueous solutions of Tween-20 and potassium thiocyanate in 1∶ 1 ( v / v) was identified as the best mobile phase for the selective separation of Co 2 + from Ni 2 + on the impregnated Silica Gel G layers. The chromatographic characteristics of the cations were studied and the limits of detection as well as the limits of quantification for Co 2 + and Ni 2 + were determined. The quantitative estimation of the cations was achieved from the digital image analysis of respective chromatograms.The proposed quantitative method was successfully applied with 0 -0． 50% error for the determination of Co 2 + from Ni 2 + in spiked samples of bauxite, soil and rock containing common cations such as Al 3 + , Fe 2 + , Ti 4 + , Zn 2 + , Mn 2 + , Cu 2 + , Cr 6 + , Mg 2 + , etc. under the optimized chromatographic conditions.