Ionenaustausch bei hohen konzentrationen der äusseren lösung : I. Mitt. Beiträge zum mechanismus der sorption von Tl(III) an dowex 50 X8 aus lösungen hoher konzentration an Cl−-, Br−- und J−-ionen
Review articleOpen access
G. Pfrepper - No affiliation found
1969/01/01 Full-length article DOI: 10.1016/S0021-9673(01)92582-8
Journal: Journal of Chromatography A
AbstractIon exchange at high concentrations of the mobile phase. Part I. The influence of high concentrations of Cl−, Br− and I− ions on the absorption mechanism of Tl(III) on Dowex 50 X8The absorption of Tl(III) from highly concentrated solutions of various metal halides on Dowex 50 X8 has been examined. The partition coefficients were shown to increase at a concentration of >2 moles/l MCl, >0.5 moles/l MBr and >0.5 moles/l MI. In the presence of 5 M NaClO4, halogen concentrations of ⩾ 0.1 moles/l cause a large increase in absorption. These findings and considerations on the invasion of electrolytes show that the increase in Kd should be ascribed explicitly to the absorption of anionic complexes of the type TlX4− by Dowex 50 X8. Conditions for the absorption are a sufficient concentration of ligands in the resin phase, as well as a high concentration of the mobile phase. Organic solvents cause desorption of the anionic complexes from Dowex 50 X8. The results obtained may indisputably be explained by the assumption that an exchange takes place between the little hydrated TlX4− ions and the organic matrix of the resin.
Request full text