Separation of phenylalanine and tyrosine by ion-exchange using a strong-base anionic resin. I. Breakthrough curves analysis

Dynamics of separations of the amino acids phenylalanine and tyrosine in fixed-bed ion-exchange column using the strongly basic resin PA 316 was investigated for different operating conditions. The flow rate, feed amino acid concentration and pH solution affect significantly the breakthrough time of the saturations curves. A mathematical model which takes into account axial dispersed plug flow, external and intraparticle mass transfer resistances, as well as non-constant selectivity coefficient data, enabled successfully to simulate the experimental breakthrough curves. The model was satisfactorily extended to prediction of the experimental dynamic behaviour of phenylalanine (Phe) and tyrosine (Tyr) mixtures where the ratio of the feed concentrations of both amino acids was changed. A most effective separation of the amino acids was achieved when the concentration of Phe in the feed solution is higher than that of Tyr.

► A strong anionic resin was used to selectively separate phenylalanine and tyrosine.
► The resin exhibited a better selectivity for tyrosine over phenylanine.
► Breakthrough curves were well described by a model with non-constant selectivity data.
► Saturation experiments were significantly affected by the operating conditions.