Nonaqueous media for separation of nonionic organic compounds by capillaryelectrophoresis

For the separation of neutral compounds by micellar electrokinetic chromato graphy, separations are usually carried out in predominantly aqueous soluti on in order to preserve the charged micelle necessary for the separation. W e now show that polycyclic aromatic hydrocarbon (PAH) compounds can be sepa rated efficiently by capillary electrophoresis in pure methanol or in aqueo us-organic mixtures containing a high percentage of methanol. Sodium tetrad ecyl sulfate was the preferred surfactant. The effects of pH, solvent compo sition, surfactant structure, and surfactant concentration on the separatio ns were studied. Reproducible migration times and linear calibration plots were obtained.