Preparation and characterization of L-phenylalanine modified chitosan resin for aromatic amino acid adsorption

A novel L-phenylalanine modified chitosan resin (PCR) was prepared for adsorption of aromatic amino acid from mixed amino acids solution. The structure and properties of PCR were observed by FTIR, C-13 NMR, AFM and SEM. PCR was found to swell rather than dissolve in acidic mediums from its solubility and swelling behavior experiments. Batch adsorption experiments were performed to evaluate the adsorption capacity, selectivity and reusability as well as its application to the removal of L-phenylalanine and tyrosine from mixed amino acids solution. The results indicated that the maximum adsorption capacity of PCR was 309.44 mg/g in sole L-phenylalanine solution at 25 A degrees C. The selectivity coefficient of L-phenylalanine, tyrosine and other amino acids on PCR indicated an overall preference for L-phenylalanine and tyrosine, which were much higher than that of non-modified chitosan resin. PCR could be reused for ten times with about 6.26% loss. This suggests that PCR is a very promising adsorbent for the selective removal of aromatic amino acid from mixed amino acids solution.