Extraction chromatographic method of preconcentration and separation of lead (II) with high molecular mass liquid cation exchanger

Abstract

A selective method has been developed for the extraction chromatographic separation of lead (II) with Versatic 911 (liquid cation exchanger) coated on silanised silica gel. Lead (II) has been extracted from 0.1 M acetate buffer at the range of pH 4.5–6.5. The effects of pH, flow-rate, stripping agents on extraction and elution have been investigated. Exchange capacity of the prepared exchanger at different temperatures with respect to lead (II) has been determined. The extraction equilibrium constant ( K ex) and different standard thermodynamic parameters have also been calculated by temperature variation method. The effect of pH on R f values in ion exchange paper chromatography has been investigated. In order to investigate the sorption isotherm, two equilibrium models, the Freundlich and Langmuir isotherms, were analyzed. Lead (II) has been separated from synthetic binary and multi-component mixtures containing various metal ions associated with it in ores and alloy samples. The method effectively permits sequential separation of lead (II) from synthetic quaternary mixture containing its congeners Cu (II), Sn (II), Hg (II) and Cu (II), Cd (II), Bi (III) of the same analytical group. The method was found effective for removal and recovery of lead (II) from industrial waste and standard alloy samples following its preconcentration on the column. A plausible mechanism for the extraction of lead (II) has been suggested.