液相制备吸附色谱流出峰对称性的若干影响因素

在色谱分离连续性方程和质量传递速率方程基础上，对色谱分离过程进行计算机模拟，定量分析了分离体系的热力学、动力学参数和操作条件对色谱流出峰形对称性的影响。结果表明，吸附相平衡关系、液固两相间的传质阻力及进料体积、进料浓度和流体线速等都将直接影响色谱流出峰形的对称性。流出峰形的不对称程度随着吸附等温线的非线性程度、液固两相间的传质阻力、流体线速、进料体积、进料浓度的增大而增大；在线性条件下，随着吸附剂吸附容量的减小而增大。

The Factors Affecting the Symmetry of Chromatographic Peak in Liquid Preparative Adsorption Chromatography

The symmetry of chromatographic elution curve has a direct influence on the separation efficiency and recovery yield. Whether the standard chromatographic peak is symmetric or not has been a disputed issue based on the plate theory or the diffusion theory in recent years. In the present paper the researches were done on the basis of continuity equation of chromatographic separation and the rate theory of mass transfer in order to show the relation between the shape of chromatographic peak and the thermodynamic and dynamic parameters, as well as operation conditions quantitatively. The non linear chromatographic separation model was established and solved by using the characteristic curve method. The factors affecting the symmetry of chromatographic curve were analyzed through computer simulation. Research results indicated that the normal chromatographic elution curve is asymmetric and the asymmetric degree of elution curves increases with the increase in the non linear degree of the system, the mass transfer resistance, the feed volume or concentration and the fluid velocity and with the decrease in the adsorption capacity of adsorbent. These results are useful to improve the separation efficiency and recovery yield.