ALPHA-CYCLODEXTRIN AS A RESTRICTED ACCESS MOBILE-PHASE FOR REVERSED-PHASE LIQUID-CHROMATOGRAPHY WITH FLUOROMETRIC DETECTION OF PHENOLIC-COMPOUNDS

A reversed-phase liquid chromatographic (LC) method to determine the p henolic derivatives, p-hydroxybenzoic (PHB), ferulic and vanillic acid s, and methyl paraben (MPB), was developed. The mobile phase used was 1x10(-2) M alpha-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 detect ion limits in the 1-5 ng ml(-1) levels. Formation constants were calcu lated from retention parameters. The method was applied to the determi nation of the phenolic compounds in beer by applying the method of sta ndard additions.