Quantitative separation of Cr 3+ from Mo 6+, W 6+, Hg 2+2, Cu 2+ and Pb 2+: Chromatographic behaviour of 51 cations on papers impregnated with Sn(IV)-based inorganic ion exchangers in complex-forming acid systems

Abstract

The chromatographic behaviour of 51 metal ions was studied on tin(IV) arsenate-, tin(IV) phosphate-, tin(IV) tungstate-, and tin(IV) molybdate- and tin(IV) selenite-impregnated papers in 0.5 M oxalic, citric and tartaric acid media. The composition and ion-exchange capacity of these papers were determined. The concentration of the anion in the exchanger deposited was found to vary directly with the p K a of the corresponding anionic acids. The selectivity of the papers for different cations is discussed. The mechanism of migration is explained in terms of ion exchange, precipitation and adsorption. A published view on the prediction of elution sequence from R F values was also checked. A number of binary and ternary separations were achieved. Cr 3+ was quantitatively separated from binary mixtures and from synthetic mixtures containing common interfering metals.