Separation and analysis of EGCG from crude tea polyphenols by high-speed countercurrent chromatography

In order to establish a novel technique of separation and analysis of EGCG from tea polyphenols using high-speed countercurrent chromatography (HSCCC), a set of HSCCC apparatus was applied to isolate and purify EGCG from tea polyphenols using two-phase solvent system composed of n-hexane-ethyl acetate-ethnol-water-acetic acid (1:5:1:5:0.25, v:v) in tail to head elution model, which the upper phase was stationary and the lower was mobile. The preferable conditions for HSCCC separation of EGCG were as follows: temperature 15°C, rotation speed 800 r/min, flow-rate 2.0 mL/min, UV detection wavelength 280 nm. The purity of EGCG was analyzed by HPLC and its structure was confirmed by ESI-MS and 1H NMR. The result suggested that EGCG with a purity of 97.5% was successively isolated and undoubtedly identified by 1H NMR and ESI-MS, which yield was 34%. HSCCC was a facile and powerful technique to separate EGCG from tea polypheols.