Micelle-mediated extraction

The extraction technique based on phase separation in aqueous micellar solutions is reviewed. The technique has now been utilized for separation and preconcentration of metal chelates, organic compounds, and proteins. Additionally, the phase behavior of the micellar solutions and recent advances in the phase separation technique are also described. In the extraction of metal chelates, distribution equilibria are considered. In contrast to conventional solvent extraction, the distribution of metal chelates into a condensed surfactant phase (surfactant-rich phase) was dependent on metal ions. Proteins were extractable into the surfactant-rich phase according to their hydrophobicity. The recent use of affinity ligands and water-soluble polymers for controlling extractability of proteins are also introduced. (C) 1997 Elsevier Science B.V.