Adsorption and Separation Behaviors of Various Amino Acids in a Gradient Chromatography

Abstract

Simulated moving bed(SMB) is a popular method to separate the amino acids. Solvent gradient SMB is an advanced SMB process with higher purity and lower desorbent consumption. To design such a process, the adsorption parameter and mass transfer coefficients are important quantitative information. In first chapter, the pulse test of blue dextran and sodium chloride were first carried out to measure the column void fraction. Then, the linear isotherm parameters of three amino acids (phenylalanine, tryptophan and tyrosine) were estimated by staircase frontal test. The experiments were conducted with a Capcell C18 column at different mobile phase composition. The adsorption parameter was correlated with the methanol concentration in mobile phase by three literature models (Snyder, Soczewinski and Abel model). The results show that Soczewinski model’s calculation result is close to the experiment result when the methanol content is from 20% (v/v) to 70% (v/v). When the methanol content was further extended to 5% (v/v), only the Abel model could be used to predict the isotherm parameters for three amino acids in the local system. The second chapter investigated the contribution of various mass transfer effects on the column separation efficiency. The mass transfer parameters of three amino acids were estimated with the established correlations. With the parameters obtained from the experimental in the previous chapter, simulation was conducted to check the staircase frontal test result. Then, the effects of various mass transfer parameters on the column efficiency were checked by analysis the column HETP value. Based on the aforementioned information, the optimal operation condition for SG-SMB can be determined in the further study.