Transfer Properties of Amino Acids from Water to Aqueous Sodium Sulfate Solutions at 298.15 K

Enthalpies of solution and densities of glycine, L-alanine, and L-serine in aqueous Solutions of Na2SO4 were measured at 298.15 K. Transfer enthalpies (Delta H-tr) and transfer partial molar Volumes (Delta V-tr(phi)0) of amino acids from water to aqueous solutions of Na2SO4 were derived. The Delta H-tr of L-alanine are positive, and the Delta H-tr of glycine and L-serine are negative. The transfer volume of all three of the amino acids are positive. The relative order in the negative Value of Delta H-tr of amino acids in the same concentration of Na2SO4 is L-serine < glycine < L-alanine, whereas the sequence of Delta V-tr(phi)0 is L-serine > glycine > L-alanine The results are discussed in terms of the cosphere overlap model.