Potentiometric Study of Dissociation Constants of Dihydroxybenzoic Acids at Reduced Ionic Strengths and Temperatures  

作　　者：Jorgen Rosenqvist Caroline M.Jonsson 

机构地区：[1]Department of Chemistry and Molecular Biology,University of Gothenburg,Gothenburg,Sweden

出　　处：《American Journal of Analytical Chemistry》2017年第2期142-150,共9页美国分析化学（英文）

基　　金：The Swedish Foundation for Strategic Environmental Research(Mistra)for financial support through the Mistra Environmental Nanosafety Program.

摘　　要：The dissociation behavior of two dihydroxybenzoic acid isomers, 2,3-DHBA and 3,4-DHBA, at 281 K and 293 K was determined by potentiometric titrations in 0.01 M NaCl and 0.03 M NaCl. Results showed that the dissociation enthalpy for the carboxylic group in DHBA is close to zero, resulting in dissociation constants that do not vary appreciably with temperature, whereas the dissociation constants for the first hydroxyl group vary significantly with temperature. Increasing ionic strength was found to result in increased values for the second dissociation constant, whereas the effect on the first dissociation constant was less clear.The dissociation behavior of two dihydroxybenzoic acid isomers, 2,3-DHBA and 3,4-DHBA, at 281 K and 293 K was determined by potentiometric titrations in 0.01 M NaCl and 0.03 M NaCl. Results showed that the dissociation enthalpy for the carboxylic group in DHBA is close to zero, resulting in dissociation constants that do not vary appreciably with temperature, whereas the dissociation constants for the first hydroxyl group vary significantly with temperature. Increasing ionic strength was found to result in increased values for the second dissociation constant, whereas the effect on the first dissociation constant was less clear.

关 键 词：2 3-Dihydroxybenzoic Acid 3 4-Dihydroxybenzoic Acid Dissociation Constant PKA Temperature Ionic Strength Surface Water 

分 类 号：O6[理学—化学]