α-Cyclodextrin as a restricted access mobile phase for reversed-phase liquid chromatography with fluorimetric detection of phenolic compounds

A reversed-phase liquid Chromatographic (LC) method to determine the phenolic derivatives, p-hydroxybenzoic (PHB), ferulic and vanillic acids, and methyl paraben (MPB), was developed. The mobile phase used was 1 × 10−2 M α-cyclodextrin/ acetate buffer pH 4.6 (1:1), that forms inclusion complexes with the analytes. The inclusion process enhances the fluorescence properties of the phenolic compounds, allowing detection limits in the 1–5 ng ml−1 levels. Formation constants were calculated from retention parameters. The method was applied to the determination of the phenolic compounds in beer by applying the method of standard additions.