Thermochemical investigation of interaction of L-serin with glycerol, ethylene glycol, and 1,2-propylene glycol in aqueous solutions

By the method of dissolution calorimetry integral enthalpies of dissolution ΔsolHm of L-serine are measured in the mixtures of water with glycerol, ethylene glycol, and 1,2-propylene glycol at the concentration of the organic solvent up to 0.42 mole fraction. The standard values of enthalpies of dissolution (ΔsolH0) and transfer (ΔtrH0) of amino acids from water to mixed solvents are calculated. The calculated values of the enthalpy coefficients of pair interactions of L-serine with the molecules of co-solvents are positive. The data obtained are interpreted in terms of prevalence of different types of interactions in solutions and the influence of nature of co-solvents on the thermochemical characteristics of the dissolved amino acids.