Analytical High Speed Countercurrent Chromatography

Abstract

The resolution of countercurrent distribution has long been demonstrated. However, the long elution time limits its analytical applications. The development of a high speed planet centrifuge has markedly improved the efficiency of the system; thus the countercurrent chromatography can be completed within several hours instead of days. Further reduction in separation time is still needed for analytical use, however. The most effective approach to improve the efficiency is to use a smaller diameter tubing for the multilayer coiled column, because it provides for better phase mixing. Under standard operation conditions, the increased phase interaction has resulted in steady carry-over of the stationary phase. This was solved with a high revolutional speed which provides the necessary centrifugal force for sustaining the stationary phase. Excellent phase retention and resolution have been achieved with a 0.85 mm i.d. column and a 2000 rpm revolutional speed. The analytical capability of the new system is evidenced by the separation of indole plant hormones, plant alkaloids and herbicides. The current resolution and speed of CCC together with its other advantages such as mild conditions, high recovery and ready semipreparative scale-up suggest the CCC can be complementary to HPLC as an analytical technique.