ABSTRACT
We have defined “coil planet centrifuge (CPC)” as a term that designates all centrifuge devices in which the coiled separation column undergoes a planetary motion, i.e., the column rotates about its own axis while revolving around the central axis of the centrifuge. Except for the original CPC, all existing CPCs are equipped with a flowthrough system so that the liquid can pass through the rotating coiled column. In most of these flow-through CPCs, the use of a conventional rotary seal device is eliminated. These sealless systems are classified into two categories according to their modes of planetary motion, i.e., synchronous and nonsynchronous (see instrumentation of countercurrent chromatography, Fig. 3). In the synchronous CPC, the coiled column rotates about its own axis during one revolution cycle, whereas in the nonsynchronous CPC, the rates of rotation and revolution of the coiled column are freely adjustable. Among several different types of CPCs, the following four instruments are described below in terms of their best applications: the original CPC, the type-J CPC, the cross-axis CPC, and the nonsynchronous CPC.
