Separation of D,L-Ampicillin by ligand exchange-micellar electrokinetic chromatography

In this study, D,L-ampicillin separation was carried out by ligand exchange-micellar electrokinetic chromatography method using L-Lysine monohydrochloride as a ligand and copper (II) sulfate pentahydrate is a central ion supplier. Isomeric separations were performed using capillary electrophoresis (CE) instrument, in which SDS-L-Lys-Cu+2 micelle complex was used as a pseudostationary phase. The effect of pH, SDS amount, applied electrical field, pressure, organic solvent ratio and ampicillin D,L-ratios were investigated. Fast, inexpensive and sensitive approach for the simultaneous separation of D,L-ampicillin in both aqueous and real antibiotic sample was performed using CE coupled with UV detector. The separation was achieved in a short period of 7 minutes with high-sensitivity and low-detection limit of 1.25 μM by the developed SDS-L-Lys-Cu+2 micelle-chiral selector complexes without using any extra process such as imprinting or spacer arms for the immobilization of the ligands.