Qz. Du et al., Van Deemter plot in high-speed countercurrent chromatography with a fixed volume of stationary phase, J LIQ CHR R, 23(19), 2000, pp. 2929-2935
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.