The solubility of α -ketoglutaric acid in water, ethyl acetate, n-butyl acetate, and the mixed solutions of these three solvents and pyruvic acid, namely water and pyruvic acid, ethyl acetate and pyruvic acid, and n-butyl acetate and pyruvic acid, was determined by the static method under normal pressure ranging from 278.15 to 293.15 K. The experimental results show that the solubility of α-ketoglutaric acid in these solvents is positively correlated with the temperature. The order of solubility in pure solvents at 284.15 K is as follows: water (12.75 × 10–2) > ethyl acetate (4.182 × 10–2) > n-butyl acetate (3.367 × 10–2). Moreover, an increase in the pyruvic acid mole fraction (yb) decreases the solubility of α-ketoglutaric acid in the three mixed solvent systems. Solubility data in pure solvents and mixed solutions are fitted with Apelblat equation, Yaws equation, van’t Hoff model, and (CNIBS)/Redlich–Kister equation, and the fitting performances are good. Furthermore, the apparent thermodynamic parameters <InlineEquation ID="IEq1"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10953_2025_1487_Article_IEq1.gif" Format="GIF" Height="21" Rendition="HTML" Resolution="72" Type="Linedraw" Width="53" /> </InlineMediaObject> <EquationSource Format="TEX">$\Delta_{\text{sol}} H_{\text m}^{^\circ }$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <msub> <mi mathvariant="normal">Δ</mi> <mtext>sol</mtext> </msub> <mmultiscripts> <mi>H</mi> <mrow> <mtext>m</mtext> </mrow> <mmultiscripts> <mrow /> <mrow /> <mo>∘</mo> </mmultiscripts> </mmultiscripts> </mrow> </math></EquationSource> </InlineEquation> <InlineEquation ID="IEq2"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10953_2025_1487_Article_IEq2.gif" Format="GIF" Height="21" Rendition="HTML" Resolution="72" Type="Linedraw" Width="52" /> </InlineMediaObject> <EquationSource Format="TEX">$\Delta_{\text{sol}} G_{\text m}^{^\circ }$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <msub> <mi mathvariant="normal">Δ</mi> <mtext>sol</mtext> </msub> <mmultiscripts> <mi>G</mi> <mrow> <mtext>m</mtext> </mrow> <mmultiscripts> <mrow /> <mrow /> <mo>∘</mo> </mmultiscripts> </mmultiscripts> </mrow> </math></EquationSource> </InlineEquation> and <InlineEquation ID="IEq3"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10953_2025_1487_Article_IEq3.gif" Format="GIF" Height="21" Rendition="HTML" Resolution="72" Type="Linedraw" Width="49" /> </InlineMediaObject> <EquationSource Format="TEX">$\Delta_{\text{sol}} S_{\text m}^{^\circ }$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <msub> <mi mathvariant="normal">Δ</mi> <mtext>sol</mtext> </msub> <mmultiscripts> <mi>S</mi> <mrow> <mtext>m</mtext> </mrow> <mmultiscripts> <mrow /> <mrow /> <mo>∘</mo> </mmultiscripts> </mmultiscripts> </mrow> </math></EquationSource> </InlineEquation> have been calculated using the Van’t Hoff equation. Both <InlineEquation ID="IEq4"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10953_2025_1487_Article_IEq1.gif" Format="GIF" Height="21" Rendition="HTML" Resolution="72" Type="Linedraw" Width="53" /> </InlineMediaObject> <EquationSource Format="TEX">$\Delta_{\text{sol}} H_{\text m}^{^\circ }$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <msub> <mi mathvariant="normal">Δ</mi> <mtext>sol</mtext> </msub> <mmultiscripts> <mi>H</mi> <mrow> <mtext>m</mtext> </mrow> <mmultiscripts> <mrow /> <mrow /> <mo>∘</mo> </mmultiscripts> </mmultiscripts> </mrow> </math></EquationSource> </InlineEquation> and <InlineEquation ID="IEq5"> <InlineMediaObject> <ImageObject Color="BlackWhite" FileRef="10953_2025_1487_Article_IEq2.gif" Format="GIF" Height="21" Rendition="HTML" Resolution="72" Type="Linedraw" Width="52" /> </InlineMediaObject> <EquationSource Format="TEX">$\Delta_{\text{sol}} G_{\text m}^{^\circ }$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <msub> <mi mathvariant="normal">Δ</mi> <mtext>sol</mtext> </msub> <mmultiscripts> <mi>G</mi> <mrow> <mtext>m</mtext> </mrow> <mmultiscripts> <mrow /> <mrow /> <mo>∘</mo> </mmultiscripts> </mmultiscripts> </mrow> </math></EquationSource> </InlineEquation> are positive values, indicating that the dissolution of α-ketoglutaric acid in these systems is an endothermic process. The solvent–solvent interactions in the mixed solvent systems are investigated by using the Materials Studio to calculate the molecular electrostatic potential through the DMol3 module and the radial distribution function through the Forcite module, and the order of the interaction strengths is consistent with that of solubility size.

Solubility of α-ketoglutaric acid in Three Solvents and Mixture Solutions of Pyruvic acid from 278.15 K to 293.15 K: Determination, Molecular Simulation, and Thermodynamic Analysis

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发表日期：

2025年7月31日

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Xiaochen He,
Kui Chen,
Lijun Ji,
Bin Wu,
Yanyang Wu,
Fan Mao

摘要

The solubility of α -ketoglutaric acid in water, ethyl acetate, n-butyl acetate, and the mixed solutions of these three solvents and pyruvic acid, namely water and pyruvic acid, ethyl acetate and pyruvic acid, and n-butyl acetate and pyruvic acid, was determined by the static method under normal pressure ranging from 278.15 to 293.15 K. The experimental results show that the solubility of α-ketoglutaric acid in these solvents is positively correlated with the temperature. The order of solubility in pure solvents at 284.15 K is as follows: water (12.75 × 10^–2) > ethyl acetate (4.182 × 10^–2) > n-butyl acetate (3.367 × 10^–2). Moreover, an increase in the pyruvic acid mole fraction (y_b) decreases the solubility of α-ketoglutaric acid in the three mixed solvent systems. Solubility data in pure solvents and mixed solutions are fitted with Apelblat equation, Yaws equation, van’t Hoff model, and (CNIBS)/Redlich–Kister equation, and the fitting performances are good. Furthermore, the apparent thermodynamic parameters $\Delta_{\text{sol}} H_{\text m}^{^\circ }$ $Δ_{sol} H_{m}^{^{\circ}}$ $\Delta_{\text{sol}} G_{\text m}^{^\circ }$ $Δ_{sol} G_{m}^{^{\circ}}$ and $\Delta_{\text{sol}} S_{\text m}^{^\circ }$ $Δ_{sol} S_{m}^{^{\circ}}$ have been calculated using the Van’t Hoff equation. Both $\Delta_{\text{sol}} H_{\text m}^{^\circ }$ $Δ_{sol} H_{m}^{^{\circ}}$ and $\Delta_{\text{sol}} G_{\text m}^{^\circ }$ $Δ_{sol} G_{m}^{^{\circ}}$ are positive values, indicating that the dissolution of α-ketoglutaric acid in these systems is an endothermic process. The solvent–solvent interactions in the mixed solvent systems are investigated by using the Materials Studio to calculate the molecular electrostatic potential through the DMol³ module and the radial distribution function through the Forcite module, and the order of the interaction strengths is consistent with that of solubility size.