Study on purification technology of polyphenols from larch barks

Macroporous resin separation was established to purify the polyphenols from larch barks.Adsorption and desorption experiments were carried out to select the suitable macroporous resin for purification process. As the response to recovery and purity of polyphenols, 6 factors such as fineness ratio, elution concentration, sample concentration, eluting speed, sample volume, and pH, were used to evaluate purification effect of polyphenols.Response surface experiment was established about three independent variables with three levels by the tool of Design-expert8.05 and the data was manipulated with it. Combined with actual needs, the optimal technological purification conditions of polyphenols were as follows: fineness ratio 1 ∶ 25, elution concentration 47%, sample concentration 2.5mg /mL, eluting speed 5mL /min, sample volume 42mL and pH6.85, in this process the verification value of purity of polyphenols was 75.66% and measured value of that was 75.52%. Analyzed through high performance liquid chromatograph, the purified liquid was discovered to contain 5 polyphenol monomers including gallic acid, catechin, chlorogenic acid, caffeic acid and ruitin, among of which the highest content of catechin was analyzed.