Comparison of cyclodextrin modified micellar electrokinetic capillary chromatography and reversed-phase liquid...

The elution mechanism of polycyclic aromatic hydrocarbons (PAHs) in cyclodextrin modified micellar electrokinetic capillary chromatography (CD-MEKC) has been compared to that in reversed-phase liquid chromatography (RPLC). The contribution of the inner surface of the capillary has been discussed mainly pertaining to the migration mechanism of PAHs. As a result, the C18-coated capillary can produce a separation field similar to that which is generally found in RPLC with the C18 alkyl bonded stationary phase, and the main migration mechanism is thought to be facilitated by the hydrophobic interaction between the solutes and the cyclodextrins (CDs). Very high linear relationships were found for log k1 versus log P in both CD-MEKC with the C18-coated capillary and RPLC with the C18 stationary phase using sodium dodecyl sulfate (SDS) as the mobile phase additive.