Research Article

Revising Reverse-Phase Chromatographic Behavior for Efficient Differentiation of Both Positional and Geometrical Isomers of Dicaffeoylquinic Acids

Figure 2

Overlaid HPLC-PDA chromatograms demonstrating the chromatographic separation of UV-irradiated samples of (a) 1,3-diCQA, (b) 1,5-diCQA, (c) 3,4-diCQA, (d) 3,5-diCQA, and (e) 4,5-diCQA analyzed on either a bi-phenyl or C18 column matrix. The figure shows differences and similarities in the elution profiles, dependent on either the bi-phenyl or C18 column matrix. T represents the di-trans-isomer, M represents the first eluting mono-cis-isomer, M# represents the second eluting mono-cis-isomer, and C represents the di-cis-isomer.
(a)
(b)
(c)
(d)
(e)