Study On Removal Of Impurities In Water Extracts Of Chinese Herbal Medicine By Flocculation Method

The traditional purification technology of a raw water extracts of Chinese herbsmedicine is primarily alcohol precipitation which drawbacks are of large dose, badstability, long production cycle, high energy consumption, and so on. In this paper，theperformance characters and the effective factors of impurities removal of raw waterextracts of a famous Chinese herb medicine–Zhisou Dingchuan oral liquid (ZDOL)by flocculation method were explored and discussed in order to promote thispurification technology application in practice production of the oral liquid.After choosing of five appropriate flocculants, the effect of the flocculant kindsand their doses on impurities removal of the raw ZDOL water extract was investigatedaccording to the evaluation indexes which were the reserved rates of ephedrine andglycyrrhizic acid and the supernatant turbidity. Then the optimal operation parametersfor the raw water extracts purification with a matched flocculant were found by theorthogonal experiment method. The effect of impurities concentration, pH value,temperature and stirring conditions on purification performance for the the raw waterextract were also studied by Single-factor flocculation experiments. Also thereasonable supernatant/flocs separation method was determined.The good results impurities removal of the raw ZDOL water extract wereachieved with the flocculant-the quaternary ammonium salt of chitosan (QASC).Under the optimum process conditions: the flocculation temperature30℃, QASC’sdosage0.4g·L-1, the fast mixing speed500r·min-1and its time1min, the slowmixing speed50r·min-1and it time10min, the retention rate of ephedrine was97.6%, the retention rate of glycyrrhizic was76.7%, the turbidity degree was1.1NTU, the retention rate of polysaccharides was88.5%, the removal percentage oftannin was63.7%and the removal percentage of protein was69.8%.The combination of sedimentation and centrifugation separation methods couldperfectly complete the supernatant/flocs separation with the recovery rate of theclarified liquid98%while the energy consumption far lower than that by thecentrifugation method alone.In a word, the results of the study showed that flocculation technology could beused to purify Chinese medicine compound water extraction. Given flocculant may absorb a bit of the active ingredients in herbal extract, it was better to choose theflocculant which has high retention rate of as many active ingredients as possible.