Rapid extraction of lead(II) from succinate media with n-octylaniline in toluene

Abstract

The distribution equilibrium of lead(II) species between aqueous succinate media and n-octylaniline was studied as a function of the concentrations of extractant in organic phase, weak organic acid concentration, different diluents and effect of shaking period on extraction. The quantitative extraction of lead(II) was observed with n-octylaniline in toluene from 0.0035 to 0.0065 M sodium succinate media in the pH range 8.0–8.3. The metal ion was stripped out from organic phase with water and determined complexometrically with disodium salt of EDTA or spectrophotometrically with PAR. The extraction of lead(II) was quantitative in most aromatic solvents, such as benzene, toluene and xylene, and oxygen containing solvents, amyl alcohol and n-butanol, and also in carbon tetrachloride. The stoichiometry of the extracted species was determined on the basis of slope analysis and found to be 1:2:2 (metal: acid: extractant). As an application the system was used for selective extraction of lead(II) from its binary mixture with Zn(II), Tl(I), Tl(III), Bi(III), Al(III), Cu(II), Th(IV), U(VI), Sn(IV), Sb(III) and Ca(II). The distribution coefficient for lead(II) in succinate media was of higher magnitude than salicylate and malonate media. This developed method was successfully applied for the analysis of lead(II) in real samples such as alloys, ores and pharmaceutical materials.