Dual Countercurrent Chromatography

Abstract
A modern method of performing conventional countercurrent distribution called Dual Countercurrent Chromatography is described. The system consists of a multilayer coiled column integrated with two inlet and two outlet lines for solvent phases and a sample feed line. Subjecting the system to a particular combination of centrifugal and planetary motions produces a unique hydrodynamic effect which allows two immiscible liquids to flow countercurrently through the coiled column. The sample solution is fed at the middle portion of the column and eluted simultaneously through the column in the opposite direction by two liquids. This distinct feature of maintaining a constant fresh two phases within the coiled column permits a rich domain of application, such as continuous sample process and continuous extraction. The present paper describes the application of this dual countercurrent system to the separation of natural products and synthetic intermediates. Preliminary results indicate that this new method has remarkably improved the efficiency of conventional countercurrent distribution. It is conceivable that dual countercurrent chromatography will become an essential tool for research in natural products, organic synthesis and biotechnology.