Solid-Phase Extraction for Sample Preparation, in the HPLC Analysis of Polyphenolic Compounds in “Fino” Sherry Wine

Wine samples are extremely complex in their content of polyphenolic compounds; this necessitates an initial fractionation prior to their analysis by HPLC, to simplify the chromatograms obtained so that they can be reliably identified and quantified. Solid-phase extraction is one of the appropriate techniques for this purpose. This paper presents the work undertaken to devise a method of fractionating polyphenolic compounds in wine; this comprises a sequence of two stages: first, one of cleaning and preconcentration, using a reversed-phase C18 cartridge, and second, one of fractionation into two groups, acid and neutral polyphenols, using a SAX-type anionic exchanger. Both of these stages have been optimized, using standard solutions, to achieve maximum recovery and reproducibility.