芳香族氨基酸在732树脂上的三组分吸附平衡

A Study of Adsorption Equilibrium for Three Aromatic Amino Acids on H^+-form 732 Cation-exchange Resins

研究芳香族氨基酸(L-色氨酸、L-苯丙氨酸和L-酪氨酸)在氢型732树脂上的三组分吸附平衡过程。考察了初始pH和温度对吸附等温线的影响,并用扩展的Freundlich模型对三组分吸附平衡过程进行了拟合。结果表明,L-Tyr、L-Trp和L-Phe的平衡吸附量随pH的减小和温度的升高而降低;当pH=1.0(即料液中存在过多H+)时,则会显著降低氨基酸在树脂上的平衡吸附量;三组分吸附行为表明,L-Trp是该三组分吸附系统中的强吸附质,L-Phe次之,而L-Tyr最弱;扩展的Freundlich模型能够较好地描述3种氨基酸在氢型732树脂上的三组分吸附平衡过程,所得的三组分吸附平衡方程在α=0.001水平上高度显著,其平均相对误差在0.34%～2.80%之间。

The process of adsorption equilibrium was investigated for the solutions of three amino acids,which consist of L-tryptophan,L-tyrosine and L-phenylalanine,adsorbed on H＋-form 732 cation-exchange resins in a constant-temperature bath.The effects of both the initial pH value and the temperature on adsorption equilibrium were studied.The adsorption equilibrium isotherms were represented with the Freundlich equation.It is showed that the equilibrium amount of adsorption for L-Tyr,L-Trp and L-Phe reduced with the decrease of the initial pH value and with the increase of temperature.And the amount of adsorption decreased significantly due to the excess of H＋ when the initial pH was 1.0.The strongest adsorbate is L-Trp,the second is L-Phe,and the weakest is L-Tyr in the adsorption system.The adsorption equilibrium isotherms for L-Tyr,L-Trp and L-Phe on H＋-form 732 cation-exchange resins could be predicted well by the extended Freundlich equation.The equations were highly significant at α=0.001 level.The mean relative errors predicted by Freundlich equations were between 0.34 % and 2.80 %.