Measurement and Correlation of the Solubility of Vanillic Acid in Eight Pure and Water + Ethanol Mixed Solvents at Temperatures from (293.15 to 323.15) K

Abstract

The solubility of vanillic acid in eight pure solvents, including ethanol, 1-propanol, 2-propanol, n-butanol, isobutanol, acetone, methyl acetate, water, and binary mixtures of water + ethanol have been measured at (293.15 to 323.15) K and atmospheric pressure by using a gravimetric method. The experimental solubility in the pure solvents was correlated by the modified Apelblat equation, van't Hoff equation, λh equation, nonrandom two-liquid (NRTL) equation, universal quasichemical (UNIQUAC) equation, and Wilson equation. The solubility in the binary mixed solvents was correlated by the modified Apelblat equation and the Jouyban−Acree equation. The correlated values based on all the selected equations showed good agreement with the experimental values, and the correlated data of the modified Apelblat equation show the best agreement with the experimental data.

Solvent and temperature effects on the solubility of syringic, vanillic or veratric acids: Experimental, modeling and solid phase studies

“…The melting temperatures and enthalpies found in literature [16,21,23,[57][58][59][60] along with the values measured in this work by DSC, and by the visual method, are summarized in Table 3. Exemplificative thermograms for the DSC measurements are shown in Fig.…”

“…The prediction analysis was also extended to the binary systems previously studied by different authors [17,20,21,24]. In Fig.…”

“…Since no modification in the crystalline structures was observed by X-ray diffraction and the measured solubilities were generally not too high, the Abraham solvation model was applied to describe the SLE of Table 3 The melting temperatures and enthalpies of the studied acids from the literature [16,21,23,57,58,61] and measured in this work.…”

“…The obtained ARDs for the correlation step were 21% for syringic acid, 15% for vanillic acid and 5% for veratric acid. Predictions were also performed for the solubility data measured in this work (1-propanol, DMF, 1,2-propanediol) and for the data available in literature [17,20,21,24], showing a global ARD of 43%. For these first set of simulations, the parameters obtained are in Table S3 of SI.…”

“…In this work, the solubility of the selected acids was measured in water and organic solvents (methanol, ethanol, 1-propanol, 2-propanol, 2-butanone, ethyl acetate, acetonitrile, dimethylformamide -DMF, 1,2propanediol, 1,3-propanediol and 1,3-butanediol) at 298.2 K and 313.2 K. For many of the studied binary systems, no solubility data have been reported yet, but whenever possible, the new solubility data were critically compared to the data available in literature. Besides a few studies concerning veratric [16,17], vanillic [18][19][20][21], and syringic acids [22][23][24] solubility, other works focused on aromatic acids with similar structures, such as o-anisic acid (2-methoxybenzoic acid) [25], p-anisic acid (4-methoxybenzoic acid) [25], 2,4-dimethoxybenzoic acid [26], 3,5-dimethoxybenzoic acid [27] and 3,4,5-trimethoxybenzoic acid [28]. In order to obtain a more complete picture of the solid-liquid equilibrium (SLE), the melting properties of the solutes were measured by Differential Scanning Calorimetry (DSC) as well as solid phase studies were carried out by X-Ray Diffraction (XRD).…”