Relationships Between Capacity Factors and Hydrophobicity of Polycyclic Aromatic Hydrocarbons in Cyclodextrin-Modified Micellar Electrokinetic Chromatography Using Surface Treated Capillaries

Abstract

The use of cyclodextrins (CDs) as a buffer additive for separation of polycyclic aromatic hydrocarbons (PAHs) in micellar electrokinetic capillary chromatography (CD-MEKC) has been studied in the relationships between the capacity factors (log k′) and their hydrophobicity (log P) using surface coated capillaries as the separation medium. Compared to the case when a surface-untreated capillary was used as the medium C₁ and C₁₈ treated capillaries gave the better linear relationships for the correlation between log k′ and log P of PAHs, because the electroosmosis flow can be neglected in the latter case and then the hydrophobic interaction between CDs and PAHs is the main function to migration of the solutes in CD-MEKC.