ABSTRACT
Countercurrent chromatography (CCC) is a liquid–liquid partition chromatography technique that operates without requiring a solid support. The original design of the toroidal coil CCC apparatus was later improved by adapting a rotary-seal-free flow-through device that was originally developed for apheresis. The development of hydrodynamic CCC systems was initiated by the introduction of various flow-through centrifuge schemes free of rotary seals. In the toroidal coil CCC, the efficiency of separation for a given solvent system may be improved by using a greater length of more tightly wound, narrower tubing. Although rotation locular CCC is less efficient than high-speed CCC, in terms of resolution and separation times, it has the advantages of a large-scale sample loading capacity and universal application of conventional two-phase solvent systems. pH-zone-refining CCC stemmed from an incidental observation that a thyroxine analog produced an unusually sharp elution peak.
