Ph-Zone-Refining Countercurrent Chromatography - A New Technique For Preparative Separation

pH-Zone-refining countercurrent chromatography (CCC) separates organic acids and bases into a succession of highly concentrated rectangular peaks that elute according to their pK(a)s and hydrophobicities. The hydrodynamic mechanism of the present method is illustrated along with a simple mathematical analysis. Examples of the application of the present method are described to demonstrate its advantage over conventional CCC. Similarities and differences between pH-zone-refining CCC, displacement chromatography, and isotachophoresis are discussed.