Analysis of the antibiotics of β-lactam by micellar electrokinetic capillary chromatography

The application of micellar electrokinetic capillary chromatography for separation and determination antibiotics of beta-lactam and beta-lactamase inhibitor was investigated. 20 mmol/L sodium tetraborate buffer (using sodium hydroxide adjusted to pH 9.5) and 38 mmol/L sodium dodecyl sulfate ( SDS) and electrophoresis voltage of 20 kV seem to provide optimal conditions for the separation and determination. Eight analytes reach the baseline separation in 15 minutes. The concentration ranges of the linearity were all about 50 similar to 600 mg/L, and the correlation coefficient is between 0.9932 and 0.9993. The relative standard deviation of 8 analytes ranges from 3.0% to 5.6%, with the limit of detection (S/N =3) 4.8 similar to 26 mg/L. The recovery is between 100% and 106% for the determination of cefoperazone-sulbactam preparation. Statistical analysis by t-test showed no significant differences between the results obtained by micellar electrokinetic capillary chromatography and by high performance liquid chromatography.