Transfer Volumes of Glycine, L–Alanine, and L–Serine from Water to 1,2-Butanediol–Water Mixtures at 298.15 K

Densities of solutions of glycine, L–alanine, and L–serine have been measured by an oscillating-tube densimeter in 1,2-butanediol–water mixtures with 1,2-butanediol mass fractions ranging from 0 to 0.35 at 298.15 K. Apparent molar volumes and limiting partial molar volumes of each amino acid have been used to obtain the corresponding transfer volumes from water to different concentrations of 1,2-butanediol–water mixtures. The transfer volumes are positive for glycine and L–serine, and both positive and negative for L–alanine over the concentration range studied. The results are interpreted in terms of solute–solvent interactions. Substituent effects are also discussed.