A simple capillary zone electrophoresis method is discussed for the simultaneous analysis of omeprazole and lansoprazole.
A simple capillary zone electrophoresis method (CZE) was established for simultaneous analysis of omeprazole (OM) and lansoprazole (LA). Untreated fused-silica capillary was operated using a phosphate buffer (50 mM, pH 9.0) under 20 kV and detection at 200 nm. Baseline separation was attained within 6 min. In method validation, calibration curves were linear over a concentration range of 5 to 100 µM, with correlation coefficients 0.9990. Relative standard deviation (RSD) and relative error (RE) were all less than 5% for the intra-day and inter-day analysis, and all recoveries were greater than 95%. The limits of detection for both omeprazole and lansoprazole were 2.0 µM (S/N = 3, hydrodynamic injection 5 s). This method was applied to determine the quality of commercial capsules. Assay results fell within 94–106%.