SEPARATION OF LIPOPHILIC COMPOUNDS BY MICELLAR ELECTROKINETIC CHROMATOGRAPHY WITH ORGANIC MODIFIERS

Separation of lipophilic compounds such as polyaromatic hydrocarbons (PAH) by micellar electrokinetic chromatography (MEKC) with organic modifiers was investigated. Dimethyl sulfoxide (DMSO) and acetone were used as organic modifiers, and sodium dodecyl sulfate (SDS) as a surfactant or a micelle forming reagent. By using 25 mM SDS (pH 7.0), containing 50% v/v DMSO, 8 PAHs were separated. Similarly, with 25 mM SDS, containing 30% acetone, 13 PAHs were successfully separated. For the calculation of thermodynamic quantities, critical micelle concentrations of SDS in buffers containing DMSO or acetone were measured.