Extracting technology of NaOH adding for emodin from radix polygoni multiflori

Objective:To research and choose the best technology and conditions for extracting emodin from radix polygoni multiflori.Methods:According to physicochemical character of emodin in radix polygoni multiflori,orthogonal design and tests of extracting technology for emodin were carried on,and three factors were chosen such as quantity of ethyl alcohol,extracting time and the quantity of NaOH adding,three levels of each factor were used for orthogonal design and test.Results:The refluent extraction with 80% alcohol as much as seven times of the medicine amount for 0.5hs and adding 0.5%NaOH as much as 12.5% of the solvent was more effective.Conclusion:The extracting time and the quantity of NaOH adding have a great influence on the extracting efficiency of smodin.