Abstract
Separation of nine commonly used active ingredients in cold medicines, were demonstrated by micellar electrokinetic chromatography. The ingredients included paracetamol, chlorpheniramine maleate, diphenhydramine hydrochloride, triprolidine hydrochloride, phenylpropanolamine hydrochloride, dextromethorphan hydrobromide, loratadine, aspirin and caffeine. Effects of buffer concentrations, pH, organic modifiers and capillary length were investigated. The optimum conditions were achieved in 10 mM sodium dihydrogenphosphate-sodium tetraborate buffer, pH 9.0, containing 50 mM sodium dodecyl sulfate and 28% v/v acetonitrile using the effective length of 50 cm, the separating voltage of +15 kV and the capillary temperature of 30°C. Separation of all peaks was obtained within 28.4 min with a resolution of 1.2.