α-氨基酸在丁酸钠水溶液中的体积性质(308.15K)

The Volumetric Properties of Some α-Amino Acids in Aqueous Sodium Butyrate Solutions at 308.15 K

Density data have been reported for glycine, DL-α-alanine, DL- α-amino-n-butyric acid, DL-valine and DL-leucin in aqueous solutions of 0. 5, 1. 0, 1. 5 and 2. 0 mol. kg - 1 sodium butyrde at 308. 15 K. The apparent molar volums V2. and standard partial molar volumes V2 for the amino acids in aqueous sodium butyrate solutions have been calculated. The linear correlation betwee V2 and the numbe of carbon atoms in the alkyl chain of the amino acids has been observed and utilized to estimate the contribuons of the chargh end groups (NH3+, COO- ), CH2 group and other alkyl chains of the nmino acids to V2. The results show that values for ( COO- ) inerease, while those for CH2 decrease, with sodium butyrate concentration-.The hydration number of the amino acids decreases With increasing electrolyte concentrations. These phenomena are discussed by means of the dehydration effect of electrolyte on the amino acids.