Moreira Maria J, Ferreira Licínio M
Department of Chemical Engineering, University of Coimbra, Polo II-Pinhal de Marrocos, 3030 Coimbra, Portugal.
J Chromatogr A. 2005 Oct 21;1092(1):101-6. doi: 10.1016/j.chroma.2005.02.017. Epub 2005 Feb 24.
This work deals with the influence of the ionic strength on the sorption of L-phenylalanine and L-tyrosine by a strong basic anion-exchange resin, converted to the hydroxide form with sodium hydroxide. Equilibrium uptake isotherms were obtained for phenylalanine and tyrosine by carrying out batch experiments at different ionic strength values of the solution. The model used to correlate these results is the modified Langmuir equation which has been applied with success to biological systems. Batch kinetic experiments were performed using a packed bed of differential length inserted in a liquid circulation loop and in which the ionic strength of the solution was varied. Moreover, an experiment at variable pH for tyrosine was also performed. Experimental transient concentration profiles were compared to those predicted by the pore diffusion model and enabled the estimation of the intraparticle diffusivities for phenylalanine and tyrosine.
本研究探讨了离子强度对强碱性阴离子交换树脂吸附L-苯丙氨酸和L-酪氨酸的影响，该树脂用氢氧化钠转化为氢氧化物形式。通过在溶液的不同离子强度值下进行间歇实验，获得了苯丙氨酸和酪氨酸的平衡吸附等温线。用于关联这些结果的模型是修正的朗缪尔方程，该方程已成功应用于生物系统。使用插入液体循环回路中的不同长度填充床进行间歇动力学实验，其中溶液的离子强度是变化的。此外，还进行了酪氨酸在可变pH下的实验。将实验瞬态浓度分布与孔扩散模型预测的分布进行比较，从而能够估算苯丙氨酸和酪氨酸的颗粒内扩散系数。
