Micellar electrokinetic capillary chromatography as an alternative method for the determination of sulfonamides and their associated compounds

A micellar electrokinetic capillary chromatography method is presented to s eparate sulfamethazine, sulfaquinoxaline, menadione, and pyrimethamine. Sep aration was carried out at 20 kV for the five first minutes and then rised to 30 kV until the end came, using 30 mM berate buffer adjusted to pH 9.2, 6% acetonitrile, and 40 mM sodium dodecyl sulfate as electrolyte. The limits of quantification were about 1 mg/L for every component. The met hod was applied in veterinary products and the results showed that some com mercial claimed levels are not in agreement with the obtained results by us ing our analytical method, as are in other cases. Finally, a HPLC method is used to determine the same mixture with similar r esults, than that provided by micellar electrokinetic capillary chromatogra phy.