AB-8大孔树脂吸附黑枸杞中花青素行为研究

通过平衡吸附实验、等温吸附实验及柱吸附实验,研究了黑枸杞中花青素在AB-8大孔树脂中的吸附行为及吸附机理。结果表明:AB-8大孔树脂对花青素的吸附可用Elovich动力学模型描述,且吸附符合Freundlich及Langmuir等温吸附模型,Freundlich模型的线性拟合性更好;此外,花青素的等温吸附焓变为正值且绝对值小于40 k J/mol,吉布斯自由能为负值,熵变为正,说明吸附过程为多层物理吸附,吸附可自发进行;由粒子内部扩散模型和Boyd模型可知吸附机理很复杂,主要受粒子扩散的影响;Adams-Bohart模型分析表明,在柱吸附分离纯化花青素过程中,应减小流动相的流量和床层高度,增加花青素质量浓度。

Adsorption Behavior of AB-8 Resin for Anthocyanins from Lycium ruthenicum Murray

The adsorption performance of AB-8 resin for anthocyanin from Lycium ruthenicum Murray and adsorption mechanism were analyzed by equilibrium adsorption experiment, isothermal adsorption experiment and column adsorption experiment. The results showed that the adsorption kinetics process of AB-8 resin for anthocyanin could well fit with Elovich kinetic model. The linear straight of regression displayed that the Freundlich model was more suitable. Moreover, the enthalpy changes were positive and the absolute value was less than 40 kJ/mol. This indicated the adsorptions of AB-8 resin for anthocyanins were endothermic and physical changes. The Gibbs free energy changes were negative. It indicated that the adsorption process occurred spontaneously. The positive value of entropy changes indicated the increased randomness during the adsorption process. The adsorption mechanism was complicated and the adsorption process was mainly affected by particle diffusion. Adams-Bohart model analysis showed that in the process of column adsorption purification anthocyanins, the flow of mobile phase and the bed height should be reduced and the quality of anthocyanin concentrations should be increased.