A quick, accurate and general ultra performance liquid chromatography method for evaluating the quality of enological tannins.

Commercial enological tannins from various origins have been widely used in modern wine making. In order to investigate the diverse quality of tannin products, a quick, accurate and simple UPLC method was developed, which could simultaneously determine 11 principle characteristic components of hydrolysable tannins and condensed tannins. The optimum resolution of the tannins was achieved on a Waters Acquity UPLC-BEH C18 column (2.1 mm × 50 mm, 1.7 μm) at 280 nm with gradient elution. The method was validated to achieve desired specificity, linearity, precision, accuracy and stability. The developed method was successfully applied to 30 commercial enological tannins from different origins for their quality evaluation. The 30 tannin samples were qualitatively distinguished into hydrolysable, condensed or mixture tannins, and quantificationally classified into four levels of excellent, good, fair and poor products. The method could be used for quick evaluating the quality of enological tannins in practical use.