Van Deemter plot in high-speed countercurrent chromatography with a fixed volume of stationary phase

An adaptability of countercurrent chromatographic data to Van Deemter equat ion (H = A + B/u + Cu) is examined under a fixed volume of the stationary p hase. Three lest samples, epigallochatechin gallate (EGCG), gallocatechin-g allate (GCG), and epicatechin gallate (ECG) were separated using a two-phas e solvent system of n-hexane/ethyl acetate/water (3.5:1:10, v/v/v) at vario us linear flow rates (u). Our mathematical treatment produced a set of formulae, H-EGCG = 6.5 + 1/u 6u; H-GCG = 6.5 + 1.3/u + 7u and H-ECG = 6.5 + 2.5/u + 9u, which showed ex cellent fit to the experimental data for each component. Constants B and C show high correlation with the partition coefficient values of three compon ents. Based on the high correlation between log u and log H when u > 1, the plate height (H) for three components may be expressed by H = Du(k), where D is the plate height at u = 1 cm/s and k, the constant for each component.