Determination of ebrotidine and its metabolites by micellar electrokinetic capillary chromatography

Ebrotidine and its potential metabolites were determined by micellar electrokinetic capillary chromatography (MECC) using sodium dodecylsulfate (SDS) as surfactant. The influences of buffer composition, SDS concentration and addition of a neutral surfactant such as Brij 35 were studied. A 40 mM phosphate buffer at pH 7.50 containing 50 mM of SDS was selected as carrier electrolyte, and provided the optimum separation with regard to resolution and migration time. Linear calibration curves over the range studied (5.0–50 μg ml−1), limits of detection between 0.25 and 2.0 μg ml−1 and run-to-run precision lower than 10% were obtained. The MECC method was applied to the determination of these compounds in spiked human urine.