Abstract:

A new adsorbent resin RH-1 was used to recover SA from sialic acid (SA) biotransformation solution. The adsorption equilibrium, adsorption kinetic and dynamic adsorption and desorption processes of SA onto the resin were investigated. The adsorption isotherms of SA at different temperatures were determined. It was observed that the adsorption capacity of SA onto the resin decreased with increase of temperature and the adsorption process was exothermic. The adsorption equilibrium could be described by the Henry adsorption model (R²=0.998). The surface diffusion model could better describe the kinetic behaviour of SA adsorption onto the resin. The fitted surface diffusion coefficient D_e was 2.19×10^-9m²/s, and SA could reach adsorption equilibrium within 10min. Finally, the SA in the conversion solution was recovered by column dynamic method. The breakthrough curves of SA on the resin under different operating conditions were investigated. The yield of SA obtained was ≥99.8% with water as the eluent. In this paper, the separation and recovery of SA can be achieved with water, which provides a new method for the green production of SA.

Key words: sialic acid, chromatographic, adsorption isotherms, fick model, dynamic adsorption

摘要：

采用一种新型的吸附树脂RH-1从唾液酸（sialic acid，SA）生物转化液中分离回收SA。研究了SA在树脂上的吸附平衡、吸附动力学以及柱动态吸附和解吸的过程。测定了不同温度条件下SA的吸附等温线，发现SA在树脂上的吸附容量随着温度升高而降低，吸附过程为放热过程，符合Henry吸附模型（R²=0.998）。表面扩散模型能较好地描述SA在树脂上的吸附动力学行为，拟合得到的表面扩散系数D_e为2.19×10^-9m²/s，SA在10min内就可以达到吸附平衡。最后通过柱动态法回收转化液中的SA，考察了SA在不同工艺条件下在树脂上的穿透曲线，水作为洗脱剂，回收得到的SA收率≥99.8%。用水就能实现SA的分离回收，为SA的绿色生产提供了一种新方法。

关键词: 唾液酸, 色谱, 吸附等温线, 表面扩散模型, 动态吸附