Densities of glycine,L-alanine and L-serine in various aqueous D-xylose solutions were measured at 298.15 K by an Anton Paar Model 55 densimeter.Apparent molar volumes,limiting partial molar volumes and hydration numbers for these amino acids were calculated.The transfer volumes from water to aqueous(D-xylose) solutions were obtained and discussed in terms of the structural hydration interaction model.The results show that all of the transfer volumes are positive,and increase with increasing xylose concentration;the side-chain contributions to the transfer volumes are highly related to the nature of side-chain groups;the hydration numbers for the three amino acids in solutions decrease with increasing xylose concentration.
