Amino acid rejection behaviour as a function of concentration

作者：Shirley Jason; Mandale Stephen^*; Williams Paul M

来源：Advances in Colloid and Interface Science, 2011, 164(1-2): 118-125.

DOI：10.1016/j.cis.2011.02.008

• Nanofiltration
• Increased rejection
• Amino acids
• Dimerisation
• Osmotic pressure

The solute rejection versus concentration behaviour of five different amino acids has been investigated using a Nitto Denko NTR7450 nanofiltration membrane. The experimental data for amino acid rejection was also compared against a combined steric and charge rejection model. At its isoelectric point, lysine was effectively neutral and its behaviour was well described by the model incorporating a steric function only. For phenylalanine, the combined model was found to fit the data well. In contrast there was poor agreement between the model and rejection data for glutamine, glutamic acid and glycine whose rejection values at first increased with concentration. This result implied that another governing process was in operation. Dimerisation as an explanation for the observed phenomena was also investigated. Size analysis of amino acid molecules as a function of the prevailing concentration using dynamic light scattering was limited but showed no evidence of dimerisation. This data was supported by osmotic pressure measurements which demonstrated no evidence of non-linearity in the relation between osmotic pressure and concentration.

• 出版日期2011-5-11