Acta Phys. -Chim. Sin. ›› 1999, Vol. 15 ›› Issue (07): 662-667.doi: 10.3866/PKU.WHXB19990716

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

Yan Zhen-Ning, Cheng Qing-Tang, Wang Jian-Ji, Liu Da-Zhuang   

  1. Department of Chemical Engineering,Tianjin University,Tianjian 300072|Department of Chemistry,Henan Normal University,Xinxiang 453002;Department of Chemical Engineering,Zhengzhou University of Technology,Zhengzhou 450002
  • Received:1998-10-15 Revised:1999-02-09 Published:1999-07-15
  • Contact: Wang Jian-Ji


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 butyrate at 308. 15 K. The apparent molar volums V2,? and standard partial molar volumes V2,?Θ for the amino acids in aqueous sodium butyrate solutions have been calculated. The linear correlation between V2 and the number of carbon atoms in the alkyl chain of the amino acids has been observed and utilized to estimate the contributions of the charged end groups (NH3+, COO- ), CH2 group and other alkyl chains of the nmino acids to V2,?Θ. The results show that values for ( COO- ) increase, 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.

Key words: Density, Standard partial molar volume, α-amino acid, Aqueous sodium butyrate solutions