物理化学学报 >> 1995, Vol. 11 >> Issue (07): 617-621.doi: 10.3866/PKU.WHXB19950710

研究论文 上一篇    下一篇

氨基酸质子化反应的滴定量热测定

刘士军,汪存信,吴绪亨,屈松生   

  1. 武汉大学化学系|武汉 430072
  • 收稿日期:1994-05-05 修回日期:1994-10-31 发布日期:1995-07-15
  • 通讯作者: 汪存信

The Determination of the Thermodynamic Functions of Protonation Reactions of Eight Kinds of Amino Acids by Titration Calorimetry

Liu Shi-Jun,Wang Cun-Xin,Wu Xu-Heng,Qu Song-Sheng   

  1. Department of Chemistry,Wuhan University,Wuhan 430072
  • Received:1994-05-05 Revised:1994-10-31 Published:1995-07-15
  • Contact: Wang Cun-Xin

摘要:

在298.2K和0.1mol•dm-3(KNO3)离子强度的实验条件下,用常规滴定量热法测定了八种氨基酸羧基质子化反应的平衡常数和反应焓变;用扩展的滴定量热法测定了这些氨基酸氨基质子化反应的平衡常数和反应焓变;并讨论了各热力学性质之间的关系.

关键词: 滴定量热法, 氨基酸, 质子化反应

Abstract:

The protonation reaction of eight kinds of amino acids-glycine, L-alanine, L-leucine, L-isoleucine, L-valine, L-phenylalanine, L-methionine, and L-tryptophan-at 298.15K and ionic strength I=0.1 (0.1 mol•dm-3 KNO3), have been studied by titration calorimetry. The thermodynamic functions of the protonation of these reactions were determined. The protonation of carboxyl group was studied by using nitric acid as titrant, and the protonation of amino group was studied by using imidazolium ion as titrant. The results are in good agreement with literature values.

Key words: Tiration calorimetry, Amino acid, Protonation reaction