Centrifugal CCD According to Akerlund

This kind of CCD machine uses centrifugation to speed up the settling of the phases. It consists of an outer ring with cavities for the lower phases (attached to a bottom plate) and an inner plate with cavities for the upper phases (Figure 6.) The inner plate can rotate relative to the outer ring. When the chambers have been loaded with systems they are covered with a lid. As in the case of the thin-layer machine the functional unit is placed on a (round) table which can be shaken. In this case, however, the table can also rotate to allow centrifugation of the mixed systems which speeds up the settling of the phases. The upper phases are then transferred to the neighbouring lower

Figure 6 Centrifugal CCD according to Akerlund. A section of the circular separation unit is shown. It is composed of four units: c, the outer ring with cavities for the lower phase: d, the inner plate with cavities for the upper phase; e, the lid; and f, an O-ring for sealing. The position of the two-phase system during centrifu-gation is shown, with the upper phase, a, and the lower phase, b. (From Johansson G, Akerlund H-E and Olde B (1984) Journalof Chromatography 311: 277, by permission.)

Figure 6 Centrifugal CCD according to Akerlund. A section of the circular separation unit is shown. It is composed of four units: c, the outer ring with cavities for the lower phase: d, the inner plate with cavities for the upper phase; e, the lid; and f, an O-ring for sealing. The position of the two-phase system during centrifu-gation is shown, with the upper phase, a, and the lower phase, b. (From Johansson G, Akerlund H-E and Olde B (1984) Journalof Chromatography 311: 277, by permission.)

phases by rotation of the inner plate when the whole system is still spinning and the phases are in a vertical position. After the transfer the centrifugation is stopped and a new cycle begins with the shaking process. After the run the phases are collected by pipette.

Continuous apparatus, such as extraction columns and coil planet centrifuges, also corresponds to a CCD process but differs in that no discrete steps are used and equilibrium is not reached.

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Solar Panel Basics

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