Analysis of phenolic compounds by high performance liquid chromatography and ultra performance liquid chromatography.

Two novel chromatographic methods both based on utilization of sub-2-micron particle columns were developed for the analysis of phenolic compounds in this work. An HPLC system was equipped with C(18) silica-based analytical column (50 mm x 4.6 mm, 1.8 microm) and a UPLC system with ethylene-bridged hybrid C(18) analytical column (100 mm x 2.1 mm, 1.7 microm). In total 34 phenolic substances were divided into groups of phenolic acids, flavonoids, catechins and coumarins and were analysed in sequence using different gradient methods. System suitability test data, including repeatability of retention time and peak area, mean values of asymmetry factor, resolution, peak capacity and the height equivalent of a theoretical plate were determined for each gradient method by 10 replicate injections. The developed methods were applied in the analysis of real samples (grape wines, teas).