Investigation of isoprenoid benzoates and naphthoates by reversed-phase liquid chromatography. Isocratic elution characteristics of benzoates and naphthoates of C₅C₂₀ terpenoid alcohols

Conditions for derivatization of C₅C₂₀ isoprenoid alcohols and the reversedphase liquid chromatographic properties of the corresponding benzoate and naphthoate esters are described. A non-linear response of log k' to changes in the composition of the mobile phase was observed on a RAdial-Pak C₁₈ column. In general, the capacity factors (k') increased with increases in carbon content an degree of saturation inthe hydrocarbon chain, and decreased with increases in branching and Z double bond content. Replacement of a single hydrogen in the methyl group at C-3 of geranyl benzoate with fluorine had little effect on k', while the difluoro- and trifuoromethyl derivatives showed regular increases in k'. The large extinction coefficients of the aromatic ester moieties, especially the 2-naphthoates, provide high sensitivity for UV detection.