High-performance Liquid Chromatographic Determination of Some Phenolic Acids of Turkish Commercial Wines: An Electrochemical Approach

In the last decade polyphenol content of wines has attracted considerable interest as antioxidants. A high-performance liquid chromatographic (HPLC) application for the determination of phenolic acids in the commercial wines of Turkey was carried out. Thirteen wine samples, differing in their origin of grape variety and vicinity, were analysed for total phenolic acid content by HPLC on C 18 -modified silica coupled with an electrochemical detector. The identification of phenolic compounds was made by comparison of their retention times with those of standards and by their electrochemical behaviour at potential of +0.650 V (vs. Ag/AgCl). HPLC analyses of wine extracts revealed the presence of gallic acid, p-hydroxybenzoic acid, syringic acid, 2,3-dihydroxybenzoic acid, ferulic acid, p-coumaric acid and vanillic acid. The phenolic compounds of wines examined ranged from 0.008 mg l -1 to 42.5 mg l -1 . Among the phenolics identified, gallic acid, p-hydroxybenzoic acid, syringic acid and ferulic acid were present in large amounts, respectively.