Journal Article

Measurement and Correlation of Solubility of L–Tryptophan in Aqueous Solutions with a Wide Range of pH and Different Monovalent Counterions from 283.15 to 323.15 K

Dai, Jiayu, Yin, Qiuxiang, Xiao, Yuntian, Yang, Wenchao, Liu, Liang, Cui, Pingping, Zhou, Ling, Jia, Lihong

2023

Overview

The aqueous solubility of L-tryptophan was measured with a wide range of pH (1.00–12.50) and different monovalent counterions (Na + , K + , Cl − and NO 3 - ) from 283.15 to 323.15 K by using a static equilibrium method. The results showed that the solubility of L-tryptophan increased with increasing temperature and the solubility–pH profile was a “U” shape with the lowest value at the isoelectric point. Additionally, the distribution of the ionic forms of L-tryptophan as a function of pH was obtained using the knowledge of the acid–base equilibria of amino acids, and it was found that the isoelectric points increased with temperature. Moreover, different counterions were introduced by using different acids or bases during pH adjustment and their effect on the solubility of L-tryptophan was investigated, which showed that more L-tryptophan could be dissolved in the presence of K + (or NO 3 - ) than Na + (or Cl − ). Besides, the modified Apelblat model and the NRTL model were successfully used to correlate the aqueous solubility data with all the average relative deviation less than 2.1%.

• Publisher: Springer US,Springer Nature B.V
• Subject: Accuracy / Amino acids / Aqueous solutions / Caustic soda / Chemistry / Chemistry and Materials Science / Chromatography / Condensed Matter Physics / Crystallization / Enzymes / Equilibrium methods / Fermentation / Geochemistry / Industrial Chemistry/Chemical Engineering / Inorganic Chemistry / Isoelectric points / Oceanography / pH effects / Physical Chemistry / Potash / Potassium / Sodium / Solubility / Solvents / Static equilibrium / Temperature / Tryptophan / Water