Solubility Determination and Thermodynamic Modeling of N-Acetylglycine in Different Solvent Systems

Abstract

N-Acetylglycine solubility in 12 monosolvents (water, methanol, ethanol, n-propanol, i-propanol, n-butanol, ibutanol, s-butanol, n-pentanol, acetone, acetonitrile, and 1,4dioxane) were determined by the static gravimetric method within the temperature range from 283.15 to 333.15 K under an ambient pressure of 98.8 kPa. In the meantime, the binary solvent mixture (methanol + acetonitrile) of different ratios was measured from 283.15 to 323.15 K. Analysis of the neat solvent data showed that the solubility behavior was influenced by the polarity, hydrogen bond, molecular structures, molecular steric hindrance, and so on. The KAT-LSER model was used to perform the multiple linear regression analysis on a pure solvent system to reveal the solvent effect on solubility. When the solvent composition was constant, a positive correlation of N-acetylglycine solubility with experimental temperature was found in all investigated pure and mixed solvent systems. At a given temperature, inflection points were found in the solubility curves for binary solvent systems as the mole fraction of methanol increased, which may be attributed to the cosolvency phenomenon. Six thermodynamic models, including the modified Apelblat, Yaws, Jouyban−Acree, Machatha, Apelblat−Jouyban− Acree, and Apelblat−Machatha models, were employed for fitting the solubility data. Article pubs.acs.org/jced

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