Analysis of clindamycin by micellar electrokinetic chromatography with a mixed micellar system

This study details the development and validation of an optimized method wi th micellar electrokinetic chromatography for the analysis of clindamycin. The method uses a mixed micellar phase containing anionic sodium dodecylsul fate (SDS) and non ionic Brij 35 on an untreated fused-silica capillary. Th e influences of buffer concentration, pH, SDS, Brij 35 and organic modifier were investigated. Special attention was given to the role of the non ioni c Brij 35 in the mixed micellar system. Optimization with a central composi te design resulted in optimal separation conditions: background electrolyte containing 25 mM sodium tetraborate pH 7.75, 90 mM SDS, 14 mM Brij 35 and 21% acetonitrile. The applied voltage was 15 W and the capillary temperatur e 15 degreesC. The method was robust and gave good linearity and repeatabil ity. The limits of detection and quantitation were 0.05 and 0.15%, respecti vely, relative to a 2.5 mg/ml clindamycin solution. Two commercial bulk pro ducts were analysed with this system. (C) 2001 Elsevier Science B.V. All ri ghts reserved.