RETENTION BEHAVIOR OF BARBITURIC-ACID DERIVATIVES ON A BETA-CYCLODEXTRIN POLYMER-COATED SILICA COLUMN

The retentions of 45 barbituric acid derivatives were determined on a beta-cyclodextrin (beta-CD) polymer-coated silica column using unbuffered methanol-water, ethanol-water, acetonitrile-water, dioxane-water and tetrahydrofuran-water eluent mixtures. Stepwise regression analysis indicated that the retention of barbituric acid derivatives is mainly governed by the lipophilicity, molar refractivity (related to the solute volume) and to a lesser extent by the electronic parameters of substituents in each eluent system, suggesting the significant importance of these physico-chemical parameters in the determination of retention behaviour. The spectral map technique indicated that the solvent strength and selectivity of organic modifiers on a beta-CD polymer-coated silica column depended on their bulkiness and electronic parameters, respectively.