ABSTRACT Countercurrent chromatography (CCC) is a preparative technique that is able to separate the components contained in a complex mixture by using multiple liquid-liquid exchanges between two immiscible liquid phases. One liquid phase is held stationary while the other liquid phase, the mobile phase, is percolated through it. To maintain the liquid phase stationary without a solid support, centrifugal fields are used. All CCC chromatographs are machines containing a rotor and a motor with its electrical regulation needed to create centrifugal fields. The technique has valuable advantages: i) loading; since the solutes to be separated have access to the volume of both liquid phases, the overloading problems, common in classical preparative chromatography with a solid stationary phase, are avoided; ii) versatility; the choice of different biphasic liquid systems is extremely large; iii) safe handling; no part of the sample can be irreversibly retained in the CCC “column” since it is always possible to collect the liquid stationary phase to recover whatever was contained in it; iv) predictability; since the liquid/liquid partition coefficient is the only parameter acting on the solute retention, peak positions are predictable, and scaling-up a separation from a smaller CCC machine to a bigger one is straightforward. This review will concisely present the CCC technique focusing on the parameters acting on a separation and giving two examples of large scale natural product purification.
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