Use of cyclodextrins for the separation of monoterpene isomers by micellarelectrokinetic capillary chromatography

The micellar electrokinetic capillary chromatographic method for the determ ination of monoterpenes such as camphene, alpha -pinene, beta -pinene, gamm a -terpinene, alpha -terpinene, terpinolene and p-cymene was established. A ddition of cyclodextrins (CDs) to the buffer solution permits the separatio n of these monoterpenes. The separation is dependent on the type of CD, and gamma-CD was the most effective cyclodextrin, in the method here developed . The method permits low concentrations of monoterpenes to be separated and detected. The addition of an organic solvent (acetonitrile) as modifier in the buffer (10 mM NaH2PO4, 6 mM Na2B4O7, 50 mM SDS, 7 mM de gamma -CD) all owed this separation. The analysis was performed with a positive power supp ly of 20 kV at a temperature of 25 degreesC. The samples were hydrostatical ly (5 s) introduced into the anodic end of the capillary and electropherogr ams were recorded at 200 nm. This method could be highly suitable for the s eparation and determination of monoterpenes in essential oils of leaves, an d the flowers of marjoram and oregano among other real samples. (C) 2001 Jo hn Wiley & Sons, Inc.