ABSTRACT
Objective To investigate the different pretreatments of Caoshanhu extract and their effects on the downstream process,membrane separation.Methods Based on the index related to isofraxidin,the different pretreatment methods of Caoshanhu extract were evaluated and their effects on membrane separation downstream were analyzed by the comparison of different pretreatments and further orthogonal test of ZTC_(1+1) Ⅲ,chitosan,and(KAl(SO_4)_2?12H_2O).Results After the pretreatment of microfiltration,both the best membrane flux and the highest percentage of isofraxidin filtered through the membrane were obtained and the time used was the least,and the ratio of isofraxidin to insoluble substances was tiptop in all pretreatment methods in comparison to other methods,such as ZTC_(1+1) Ⅲ,chitosan,and(KAl(SO_4)_2?12H_2O) methods.Conclusion Microfiltration is a better pretreatment method in preparation of Caoshanhu extract.