Solubility of trisodium citrate in water + methanol mixtures at various temperatures

Abstract

A laser based automated setup was employed to experimentally determine the solubility of anhydrous trisodium citrate in binary mixtures of water and methanol under atmospheric pressure within the temperature range of 293.2 K to 313.3 K. The measured mole fraction solubility of citrate was around 5 -- 10- 2 in pure water and decreased by one order of magnitude to 5 -- 10- 3 at mole fraction of methanol of 0.3 in the binary mixture; within the investigated composition of the mixed solvent the solubility remained then at a low level and was about 10- 4 at methanol mole fraction of 0.69. In all solvents the solubility increased with increasing temperature; the effect was more pronounced in the mixed solvents than in the pure aqueous solution. In order to extend the solubility data for practical applications, the experimental values were correlated to a semi-empirical combined model of Jouyban-Acree and van't Hoff, resulting in calculated solubilities which agreed with the experimental ones within a mean percentage deviation (MPD) of approximately 10.8%. © 2016 Elsevier B.V.