Retention behavior of quinolones in reversed-phase liquid chromatography

Quantitative structure-retention relationships (QSRRs) have been used successfully to predict and explain retention behavior in reversed-phase liquid chromatography (RPLC). The informative structural descriptors for quinolones on a PRP-1 column and aqueous organic solvent system were proposed. Since quinolones are ionizable, the retention behavior of quinolones was investigated at both pH 3 and pH 11. Cluster analysis was applied to assign compounds to specific categories according to k'-value. Based on this analysis quinolones could be divided into two groups regardless of the organic modifier and pH. At pH 3, the solvent-accessible surface area was an informative descriptor which could explain the retention behavior of quinolones. In contrast, the gamma-component of the dipole moment was a useful descriptor at pH 11. Calculations for finding descriptors were performed by MM+ and AM1 methods.