Study on the purification technology of medicinal fulvic acid

Purification technology of medicinal fulvic acid (FA) was established by 001×7 cation exchange resin.According to the investigation of technological parameters, the optimized technical conditions were obtained as fallows:the ratio of resin usage amount to FA usage amount was 25∶1 (volume-weight ratio, mL/g) .The ion exchange time lasted for 140min.Then freeze drying.The ash content of the refined FA prepared through this technology was all less than 1%, in which the content of As was 0.31mg/kg, Cd below 0.1mg/kg, Pb and Cr below 0.5mg/kg, and Hg below 0.05mg/kg.The purity and contents of harmful elements of the refined FA both reached to medicinal and edible levels.Meanwhile, the activity of refined FA was relatively enhanced by purification.The new technology, which was simple, effective and lower cost, not only provided technical support for the preparation of refined FA, but also provided security for the application of FA in the fields of medicine and functional food.