Physicochemical regularities of retention of phenolic compounds in reversed-phase high-performance liquid chromatography

The retention of benzene, phenol, and its derivatives with hydroxyl, methyl, and glycoside groups in the benzene ring in the reversed-phase high-performance liquid chromatography on Separon SGX C-18 with the acetonitrile-water binary mobile phase was studied. It was shown that the Scott-Kucera model fails to describe the chromatographic retention of phenolic compounds over a wide range of modifier (acetonitrile) concentrations (from 10 to 70 vol %). The quasi-chemical displacement model more adequately describes the chromatographic retention of the investigated compounds. Equilibrium constants of quasi-chemical reactions of adsorption of the investigated compounds and their association with the modifier in the mobile phase were calculated.