物理化学学报 >> 2004, Vol. 20 >> Issue (01): 15-20.doi: 10.3866/PKU.WHXB20040104

研究论文 上一篇    下一篇

L-苏氨酸在糖及维生素C水溶液中的体积性质

赵长伟;马沛生;朱春英;赵树志   

  1. 天津大学化工学院,天津 300072
  • 收稿日期:2003-06-20 修回日期:2003-08-20 发布日期:2004-01-15
  • 通讯作者: 马沛生 E-mail:mapeisheng@tju.edu.cn

Volumetric Properties of L-threonine in Aqueous Glucose, Sucrose and L-ascorbic Acid Solutions

Zhao Chang-Wei;Ma Pei-Sheng;Zhu Chun-Ying;Zhao Shu-Zhi   

  1. School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072
  • Received:2003-06-20 Revised:2003-08-20 Published:2004-01-15
  • Contact: Ma Pei-Sheng E-mail:mapeisheng@tju.edu.cn

摘要: 用精密数字密度计和粘度计测定了L-苏氨酸在不同质量分数的葡萄糖、蔗糖及维生素C水溶液中的密度和粘度,计算了L-苏氨酸的极限偏摩尔体积、迁移偏摩尔体积、理论水化数和粘度B系数,讨论了溶剂组成变化对L-苏氨酸迁移偏摩尔体积、粘度B系数和理论水化数的影响.结果表明,随混合溶剂中共溶质含量的增加,迁移偏摩尔体积、粘度B系数随之增加;而由于葡萄糖、蔗糖及维生素C分子与L-苏氨酸荷电中心的直接相互作用,削弱了两性离子带电中心对周围水分子的电致收缩效应,造成了理论水化数随其含量的增加而减小.

关键词: L-苏氨酸, 葡萄糖, 蔗糖, 维生素C, 体积, 粘度

Abstract: Amino acids and their derivatives are useful as models of specific aspects of more complex proteins in aqueous solution. In this paper, densities and viscosities of L-threonine in glucose-water, sucrose-water and L-ascorbic acid-water mixed solvents have been measured at 298.15 K by an oscillating-tube densimeter and a viscositymeter . Limiting partial molar volume, transfer partial molar volume, number of hydration and viscosity B-coefficients of L-threonine have been calculated. The viscosity B-coefficients and the numbers of hydration of L-threonine mixed solvent vary with mass concentration of sugar or L-ascorbic acid. The transfer partial molar volumes from water to sugar-water or L-ascorbic acid-water mixtures have been obtained and discussed in terms of the structural hydration interaction model. The results indicate that the transfer partial molar volumes and viscosity B-coefficients of L-threonine increase with increasing of the mass concentration of sugar or L-ascorbic acid, and the hydration numbers of L-threonine decrease owing to the interaction of sugar or L-ascorbic acid with the zwitterionic groups. It is concluded that the degrees of the effect on volume and hydration number are related to the number of OH groups and the structure of mixture solvent.

Key words: L-threonine, Glucose, Sucrose, L-ascorbic acid, Volume, Viscosity