PRECONCENTRATION AND SELECTIVE METAL-ION SEPARATION USING CHELATING MICELLES

Chelating aggregates consisting of Triton X100 host micelles and hydro phobic derivatives of PAN have been examined as suitable candidates fo r preconcentration and selective separation of transition metal ions t hrough micellar-enhanced ultrafiltration. The effective accumulation i n the surfactant-rich retentate of nickel(II), copper(II), cobalt(II), manganese(II) and zinc(II), present at trace levels in aqueous sample s, has been achieved by operating at pH ca. 6 with a ligand having a b inding constant to the host micelles higher than 2000 l./mol. The effi cient separation of micelle-bound metal chelates from unreactive ions has been assessed, together with the feasibility of selective enrichme nt and purification of the investigated metal ions present in mixtures through a multistage process.