Analysis of Antibiotic Flumequine and Related Impurities in Mixed-Mode Chromatography

Flumequine is a fluoroquinolone antibiotic widely used in veterinary medicine. Residues of flumequine and its related impurities have been detected in animals later processed for meat consumption. Analysis was performed using mixed-mode chromatography on Zodiac HST RP, a reversed-phase column with embedded basic ion-pairing groups, and Zodiac HST TH, a trimodal column that combines reversed-phase, ion-exchange, and normal-phase separation mechanisms. This method is LC/MS-compatible and enables effective separation of flumequine and its related impurities in complex sample matrices.