大孔树脂吸附南五味子总三萜的动力学和热力学分析

Adsorption Kinetics and Thermodynamics Analysis of Macroporous Resin for Total Triterpenoids in Schizandrae Sphenantherae Fructus

目的：考察大孔树脂吸附南五味子总三萜的动力学与热力学特征,为该类化合物的分离纯化提供参考。方法：以吸附率、洗脱率为综合评价指标,通过静态吸附-洗脱试验从11种大孔树脂中筛选最适合纯化南五味子总三萜的大孔树脂类型,建立AB-8型树脂纯化南五味子总三萜的吸附动力学模型和等温吸附模型,并计算热力学参数。结果：选择AB-8型树脂,该树脂对南五味子总三萜在0～50 min为快速吸附阶段,50～200 min为缓慢吸附阶段,200 min后为吸附饱和阶段。AB-8型树脂对南五味子总三萜的吸附行为符合准二级吸附动力学方程,吸附速率由液膜扩散和颗粒内扩散共同控制;平衡吸附数据符合Freundlich等温方程,属于多分子层吸附;高温有利于吸附。结论：AB-8型树脂对南五味子总三萜的吸附为熵推动过程,固-液界面上分子运动更为混乱,有更多水分子杂乱地由固体表面向溶液中运动,为南五味子总三萜的纯化工艺优选具有一定指导意义。

Objective： To investigate adsorption kinetics and thermodynamic characteristics of macroporous resin for total triterpenoids from Schizandrae Sphenantherae Fructus,in order to provide a reference for separation and purification of these compounds. Method： With adsorption and elution rate as indexes,optimum type of macroporous resin for purification of total triterpenoids was selected from 11 kinds of macroporous resin by static adsorption and desorption test,then adsorption kinetics model and adsorption isotherm model of total triterpenoids were established by AB-8 resin and calculated thermodynamic parameters. Result： AB-8 resin was selected,resin adsorption processor for total triterpenoids showed fast adsorption stage in 0-50 minutes and slow adsorption stage in 50-200 minutes, adsorption after 200 minutes was saturation stage. Adsorption dynamic behavior was well described by quasi-second-order kinetics equation,adsorption rate was mainly controlled by liquid film diffusion and intraparticle diffusion; equilibrium adsorption data were fitted Freundlich isotherm equation which was belonging to multi-molecular layer adsorption; high temperature was advantageous to adsorption. Conclusion： Adsorption process of AB-8 resin for total triterpenoids was driven by entropy,solidliquid interface molecular motion was more confusion,more water molecules promiscuously moved from solid surface to solution,which had a certain guiding significance for optimizing purification process of total triterpenoids from Schizandrae Sphenantherae Fructus.