Column chromatography separation preparation of catechins without ethyl acetate

Objective:To explore the technology of the preparation of no ethyl acetate catechins.Methods:Based on previous studies, using the dust and broken tea as raw materials, ethanol and resins were used for the preparation of no ethyl acetate catechins.Firstly, taking the ethanol concentration of 80% as solvent to extract the tea.The extraction conditions were tea leaves-to-ethanol ratio of 1:20, extraction time of 50min and extraction temperature of 70℃.Secondly, on the basis of the resin screening test and column efficiency test, the dynamic adsorption and desorption test were designed to optimize the technology conditions of dynamic adsorption and desorption of catechin.Results:Under the optimum extraction conditions, the leaching rate of catechin was 20.16%.Polyamide resin was screened for the purification of catechins.The optimal adsorption conditions were sample flow velocity in 1BV/h, concentration of tea of 20mg/mL.The optimal deabsorption conditions were flow rate of 1BV/h, gradient elution with 1.2BV water, 1BV 25% ethanol and 1BV 80% ethanol solution respectively.The prepared catechin contained total catechins≥80%, EGCG≥60%, CAF≤0.5%, and the yield≥7%.Conclusion:According to the best technical conditions of the trial for the preparation of no ethyl acetate catechins, the product was fully meeting the requirements of no ethyl acetate catechins.