Co-current chromatography: A new mode of liquid-liquid chromatography

When two immiscible solvents are forced to flow simultaneously through narrow tubing, the resultant flow consists of alternating discrete segments of each phase. One solvent, the continuous phase, forms a stationary wetting film along the walls of the tubing. If this film is sufficiently thick, a difference in the velocities will develop between the two phases which can be used for chemical separation. This differential velocity forms the basis for a new mode of liquid-liquid chromatography termed “co-current chromatography”. Equations describing the retention and band-broadening behavior in co-current chromatography are derived and experimentally verified.