Chromatographic study of terpene derivatives on porous graphitic carbon stationary phase with β-cyclodextrin as mobile phase modifier

The stoichiometric coefficients and apparent formation constants (Kf) of α-terpineol, thymol, geraniol and linalool complexes with β-cyclodextrin (β-CD) were determined using HPLC with a porous graphitic carbon (PGC) chromatographic support. Measurements were performed with four different methanol–water mobile phases. All the terpene derivatives under study form 1:1 guest–CD complexes. Graphs of Kf as a function of the mobile phase composition appeared different from those classically described for RP-C18 and suggest that the PGC stationary phase could play an active role in the complexation process. Solute–CD inclusion and solute–stationary phase interactions may be involved in this specific behavior.