LINEAR SOLVATION ENERGY RELATIONSHIPS IN REVERSED-PHASE LIQUID-CHROMATOGRAPHY - PREDICTION OF RETENTION OF SEVERAL QUINOLONES

In this study the proportion of the organic modifier and the pH of the hydroorganic mobile phase were optimized in order to separate four important and widely used quinolones: ciprofloxacin, norfloxacin, ofloxacin and pipemidic acid. The Linear Solvation Energy Relationships (LSER) method based on the multiparameter scale developed by Kamlet and Taft can be succesfully used to select the right composition of the eluent and it has been shown that plots of log k' versus the Reichardt's E(T)(N) parameter of the mobile phase are linearly correlated for the solutes studied. Moreover, pH measurements in acetonitrile-water mixtures used as mobile phases have been made, taking into account the reference pH values previously established, in order to optimize the pH of the mobile phase for the chromatographic separation of the four quinolones studied.