Abstract In this research, solubility of kojic acid in fourteen mono-solvents was obtained by laser monitoring approach at various temperatures under 0.1 MPa. The mole solubility of kojic acid exhibited a positive relation with temperature. Moreover, the solubility sequence of kojic acid at 298.15 K is: dimethyl sulfoxide (DMSO) > N-methylpyrrolidone (NMP) > N, N-dimethylacetamide (DMAC) > N, N-dimethylformamide (DMF) > 2-methoxyethanol > 2-ethoxyethanol > acetic acid > methanol > 1,4-dioxane > ethanol > water > n-propanol > acetone > ethyl acetate. The Hansen solubility parameter (HSP) and solvents polarity were applied to explore this solubility behaviour. The experimental solubility data was correlated with five thermodynamic models including two-Suffix Margules, NRTL-SAC, NRTL, modified Apelblat equation and UNIQUAC model, and the calculated results indicated that all of models had great fitting effects with the measured solubility data. Furthermore, the solution thermodynamic properties (ΔdisGo, ΔdisHo, ΔdisSo) of kojic acid in investigated solvents were calculated by van’t Hoff equation. The positive values of ΔdisHo and ΔdisSo indicated that the dissolution process of kojic acid in all the measured solvents was endothermic and entropy-driven.

中文翻译：

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十四种单一溶剂中的曲酸：溶解度数据、汉森溶解度参数和热力学性质

摘要 本研究采用激光监测方法，在0.1 MPa以下的不同温度下获得曲酸在14种单溶剂中的溶解度。曲酸的摩尔溶解度与温度呈正相关。此外，曲酸在298.15 K的溶解度顺序为：二甲亚砜（DMSO）> N-甲基吡咯烷酮（NMP）> N，N-二甲基乙酰胺（DMAC）> N，N-二甲基甲酰胺（DMF）> 2-甲氧基乙醇> 2-乙氧基乙醇 > 乙酸 > 甲醇 > 1,4-二恶烷 > 乙醇 > 水 > 正丙醇 > 丙酮 > 乙酸乙酯。应用汉森溶解度参数 (HSP) 和溶剂极性来探索这种溶解度行为。实验溶解度数据与五个热力学模型相关，包括两个后缀 Margules、NRTL-SAC、NRTL、修正Apelblat方程和UNIQUAC模型，计算结果表明，所有模型与实测溶解度数据拟合效果良好。此外，通过van't Hoff方程计算了曲酸在所研究溶剂中的溶液热力学性质（ΔdisGo、ΔdisHo、ΔdisSo）。ΔdisHo 和 ΔdisSo 的正值表明曲酸在所有测量溶剂中的溶解过程是吸热和熵驱动的。