Determination of vancomycin in human serum by micellar electrokinetic capillary chromatography with direct sample injection

Background: Vancomycin (VCM) has a bacteriostatic effect on gram-positive bacteria such as the methicillin-resistant Staphylococcus aureus. Methods: A new assay for measuring vancomycin concentration by micellar electrokinetic capillary chromatography using direct serum injection was developed. A borate buffer (pH 10.0) containing 100 mmol/l sodium dodecyl sulfate was used as an electrophoresis buffer, and the detection was at 210 nm. The migration time of vancomycin was similar to7 min. Results: The linearity was from 0 to 100 mug/ml, with the limit of detection of 1.0 mug/ml (S/N=3). The within-run CV was 3.99-5.53%, and the recovery rate was 91-103% for a concentration range of 6.5-45.5 mug/ml. The between-day CV was 6.76% at 22.2 mug/mL There was no interference from 32 other antibiotics. The correlation coefficient between the assay and fluorescence polarization immunoassay and direct injection HPLC was 0.982 and 0.985, respectively. The assay required no sample preparation of serum and used only microquantities of an electrophoresis buffer and samples. Conclusions: This assay is cost-effective and suitable for routine clinical use. (C) 2001 Elsevier Science B.V. All rights reserved.