Rapid Determination of 4-Vinyl Guaiacol and Ferulic Acid in Beers and Worts by High-Performance Liquid Chromatography

Sensitive methods for the determination of ferulic acid and 4-vinyl guaiacol in beers and worts are described. Samples were analyzed by direct-injection high-performance liquid chromatography using an octadecyl silica column. Detection was by either fluorescence monitoring (for 4-vinyl guaiacol alone) or electrochemical detection (for simultaneous determination of ferulic acid and 4-vinyl guaiacol). The methods were applied mainly to the analysis of production beers but were used also to monitor the decarboxylation of ferulic acid to 4-vinyl guaiacol in wort during a small-scale fermentation deliberately contaminated with a wild yeast strain.