Assessing the separation of neutral plant secondary metabolites by micellar electrokinetic chromatography

In this work, partition coefficients (P-wm) and solute-micelle association constants per monomer (K-m/N) were measured using micellar electrokinetic chromatography in tetraborate-sodium dodecylsulfate electrolytes for 18 important plant secondary metabolites (coumarin, verbenone, camphor, eucalyptol, carvone, alpha-terpineol, linalool, jasmone, bergapten, rose oxide, geraniol, t-anethole, citronellal, citronellol, p-cymene, limonene, caryophyllene and nerol) of wide occurrence in herbal extracts and essential oils. Caryophyllene presented a retention time longer than anthracene (micelle marker) and its set of constants could not be determined accurately. P-wm and K. IN were generated by the non-linear data fitting of both partition and solute-micelle association models for the 17 solutes under consideration (caryophyllene excluded). P-wm varied from 147 (coumarin) to 13 175 (limonene) while K-m/N varied from 37 (coumarin) to 3721 (limonene). Under optimal conditions, the separation of the selected compounds was attempted successfully in commercialized samples of rose, anise and geranium essential oils. (C) 2003 Elsevier B.V. All rights reserved.