吸附剂性能和操作参数对液相色谱流出峰不对称性的影响

色谱流出峰的拖尾现象普遍存在于制备和大型色谱分离过程中，它直接影响分离的产率和回收率．本文提出采用色谱流出峰形的不对称偏差度来表征色谱流出峰的拖尾程度；并基于液相制备色谱分离过程FAD－SMT模型及吸附速率理论，通过计算机模拟，定量分析了吸附剂性能和操作参数对色谱流出峰形不对称性的影响。结果表明：不仅是吸附剂的热力学和动力学性能（包括吸附相平衡关系、液固两相间的传质阻力）；而且柱的设计和吸附剂的装填状况（包括轴向扩散系数），以及色谱分离的操作条件（进料时间、浓度和流速等）都直接影响色谱流出峰形的不对称性。随着吸附相平衡等温线的非线性程度增大，或者总传质系数的减小，色谱流出峰形的不对称偏差度明显增大；吸附剂吸附容量的减小也将引起色谱流出峰形的不对称偏差度的增加；色谱流出峰形的不对称偏差度与进科体积、浓度和流体线速，以及轴向扩散系数的增大成正比。

THE EFFECTS OF THE PROPERTIES OF ADSORBENT AND THE OPERATION PARAMETERS OF LIQUID ADSORPTION CHROMATOGRAPHY ON THE ASYMMETRV OF CHROMATOGRAPHIC ELUTION CURVE

The tailed phenomenon of chromatographic elution peak universally exists in the large scale liquid chromatographic separation process and directly affects the production rate and recovery rate of chromatographic separation. The paper suggests that the asymmetric degree of chromatographic elution peak shape is used to characterize the tailed degree of the chromatographic elution peak and quantitatively analyses the effects of the properties of adsorbent and the operating parameters on the asymmetric degree of the chromatographic elution peak shape by means of the computer simulation of the chromatographic separation process on the basis of large scale liquid chromatography FAD-SMT model and adsorption rate theory. The research results show that the asymmetric degree of the chromatographic elution is not only influenced by the thermodynamics properties and the dynamics properties of adsorbent, but also directly influenced by the column design, loading condition and the operation parameters of the chromatographic separation. The asymmetric degree of the chromatographic elution peaks increases with the increasing in the non-linear degree of absorption isotherm, with the decreasing in the lumped mass transfer coefficients, with the decreasing in the absorption capacity of the adsorbent, with the increasing in the axial dispersion coefficients, with the increasing in the volume and concentration of feed, and with the increasing in the fluid velocity.