The pH Influence on the HPLC-Retention of Chemotherapeutic Fluoroquinolone Derivatives

摘要

The gyrase inhibitor fluoroquinolone derivatives were investigated by RP-HPLC methods in C18/methanol-phosphate buffer system. Considering the amphoteric feature of the substances it was reasonable to study the relationship between their chromatographic behaviour vs. pH of the mobil phase. The formation of k1values was characterized by a maximum curve, and the retention maxima could be found close to or at the pH values of isoelectric point of the compounds. This may be explained by the presence of the zwitter ionic or the unionized form of the derivatives at this pH value.