HIGH-SPEED COUNTERCURRENT CHROMATOGRAPHY OF DIPEPTIDES ON A POLAR 2-PHASE SOLVENT SYSTEM

The performance of the high-speed countercurrent chomatograph was evaluated by separating dipeptide samples on a polar biphasic solvent composed of n-butanol-acetic acid-water (4:1:5, v/v/v). Best results were obtained with a set of multilayer coils of small helical diameter by eluting with the upper nonaqueous phase in a head to tail direction at a flow rate of 1 or 2 ml/min. Four components were completely resolved in 5 to 11 hours. Other types of coiled column such as a multilayer coil with large helical diameter (in a commercial model) and eccentric dual-layer coil assemblies mounted on a horizontal coil planet centrifuge also yielded satisfactory separations.