Partial molal volumes and expansibilities of some amino acids in aqueous solutions

Partial molal volumes ((V) over bar(2)(0)) at infinite dilution of glycine, DL-alanine, beta-alanine, DL-alpha-amino-n-butyric acid, L-valine, L-Leuci ne, L-isoleucine, L-phenylalanine, L-serine, L-threonine, L-proline and L-g lutamic acid have been determined by density measurements using pycnometer at 298.15, 308.15 and 318.15 K. These data in conjunction with the reported values at other temperatures have been utilized to estimate the precise pa rtial molal expansibilities (partial derivative (V) over bar(2)(0)/partial derivative T)p at infinite dilution and the values of (partial derivative(2 )(V) over bar(2)(0)/partial derivative T-2)p by different procedures. These parameters have been used to predict the structural hydration effects, i.e . the structure-making and structure-breaking effects of solutes in solutio ns. The precise values of (partial derivative (V) over bar(2)(0)/partial de rivative T)p have been used to convert the partial molal adiabatic compress ibilities of the studied solutes to partial molal isothermal compressibilit ies at infinite dilution which is an ideal parameter for interpreting the r esults.