对氨基水杨酸在有机溶剂中的溶解度与热力学性质研究

采用重量分析法在300.15～324.05 K温度范围内测定对氨基水杨酸在乙醇、正丙醇、异丙醇、正丁醇、异丁醇、丙酮、醋酸甲酯、醋酸乙酯8种纯溶剂中的溶解度。结果显示对氨基水杨酸的溶解度随着温度的升高而单调递增。将实验测定的溶解度数据与6种理论方程(Apelblat、van’t Hoff、λh、NRTL、Wilson、UNIQUAC)进行关联，在纯溶剂中关联结果的平均相对误差分别为0.79%、2.36%、2.71%、1.64%、1.72%、1.61%。结果表明，6种热力学模型对对氨基水杨酸的溶解过程都有很好的关联效果，其中Apelblat方程的关联效果最佳。运用汉森溶解度参数分析对氨基水杨酸的溶解行为；采用van’t Hoff方程计算对氨基水杨酸溶解过程中溶解焓ΔH_sol、溶解熵ΔS_sol、溶解吉布斯自由能ΔG_sol等热力学参数，结果显示对氨基水杨酸的溶解是一个吸热、非自发的过程。     

酒石酸钠二水合物的溶解度测定及关联

用动态法测定了酒石酸钠二水合物在不同质量配比的乙醇-水混合溶剂中的溶解度,以期为酒石酸钠二水合物提供结晶热力学数据。结果表明:酒石酸钠二水合物在乙醇-水混合溶剂中的溶解度随水质量分数和温度的增加而增加,但随着水质量分数的增加,升高温度对酒石酸钠溶解度的增加量逐渐变小。采用Modified Apelblat,Van't-JA及Apel-JA方程对溶解度数据进行了关联,均方根偏差最大为6.24×10~(-4)。所选热力学方程均能很好的关联溶解度数据,其中Modified Apelblat方程的关联效果最好。此外,采用Van't Hoff方程计算了酒石酸钠二水合物在乙醇-水混合溶剂中的表观溶解热力学数据,数据表明其溶解过程为非自发的吸热过程。     

胆酸在5种溶剂中的溶解度测定及关联

采用重量法测定了胆酸在甲醇、乙醇、乙酸乙酯、冰醋酸和正丙醇中的溶解度数据，并采用Modified Apelblat模型、λh模型、二次多项式模型和三参数van’tHoff模型对溶解度数据进行了拟合。通过修正的van’tHoff方程分析溶解过程的热力学参数(吉布斯自由能变Δ_mixG、焓变Δ_mixH和熵变Δ_mixS)，并计算了焓相对贡献ζH和熵相对贡献ζ_TS。结果表明，二次多项式模型对溶解度的关联效果最好。在研究所采用的溶剂体系中，Δ_mixH>0，Δ_mixS>0，Δ_mixG>0，说明胆酸的溶解是非自发、不可逆的吸热过程。焓的相对贡献ζ_H远大于熵的相对贡献ζ_TS，说明胆酸在所选的溶剂的溶解过程中，溶解焓变Δ_solH对溶解吉布斯能变Δ_solG的贡献大于溶解熵变Δ_solS。这些溶解度和热力学性质可为胆酸结晶工艺提供重要...     

地高辛在不同溶剂中的溶解度测定及关联

在278. 15～323. 15 K下采用静态平衡法测定了地高辛在乙醇、甲醇、异丙醇、甲醇-水体系(甲醇体积分数为80%)及乙醇-水体系(乙醇体积分数为80%、60%、40%、20%)中的溶解度数据,采用Apelblat方程、多项式经验方程和λh方程对地高辛的溶解度进行关联。实验结果表明,8种溶剂中,地高辛的溶解度均随温度的升高而增加,在80%乙醇水混合溶剂中溶解度最大,在20%乙醇水中溶解度最小,几种热力学模型对地高辛的关联效果也很好。经热力学理论分析,计算溶解焓与溶解熵可知地高辛的溶解过程为吸热过程。地高辛溶解度的测定及关联为其工业化纯化溶剂的选择提供重要理论依据。     

碳酸锂在水中的溶解度和超溶解度的测定及热力学分析

固体溶质在溶剂中的溶解度和超溶解度数值决定了结晶介稳区的宽度,而溶质结晶分离过程又是在介稳区中进行操作,因此固体溶质的溶解度和超溶解度在工业结晶中是很重要的基础数据。本文以碳酸锂为溶质,在标准压力条件和283.15~318.15K温度条件下,用重量分析法测定其在水中的溶解度;用激光动态法测定其在一定温度条件下在水中的超溶解度,从而得到碳酸锂在水溶液中的介稳区;结果显示,碳酸锂在水中的溶解度和超溶解度均随温度的升高而减小,介稳区宽度随温度的升高而变窄;其溶解度数据用Van't Hoff方程和修正的Apelblat方程进行了热力学关联计算,结果表明,两种热力学模型对碳酸锂在水中溶解度的关联效果都很好,其中Van't Hoff方程和修正的Apelblat方程的计算值与实验值的平均相对偏差分别为0.54%和0.20%。通过溶解热力学计算,得到碳酸锂在水中的溶解焓ΔH_d、熔解熵ΔS_d和溶液标准吉布斯自由能变ΔG_d,结果表明该溶解过程为放热熵减小的非自发过程,并且溶解熵变对溶解过程的影响较大。     

α-对氨基苯甲酸的固液平衡及热力学性质研究

为优化α-对氨基苯甲酸(PABA)的结晶工艺以及提供基础热力学数据,采用动态激光法在温度为283.15—313.15 K温度范围内测定了对氨基苯甲酸在2种混合溶剂(水+乙醇,水+甲醇)中的固液平衡数据。结果表明:PABA的溶解度随着温度和有机溶剂的增加而增加,并且在水+乙醇混合溶剂中高温时存在潜溶现象。用RK方程、Apelblat方程、λh方程对其在混合溶剂中的溶解度数据进行拟合关联,均取得较好结果:平均标准偏差(ARD%)分别为1.664%,2.878%;1.317%,1.245%;1.667%,2.232%。考虑活度系数,用NRTL计算了其混合热力学性质混焓、混合熵、混合吉布斯自由能,结果表明PABA的混合过程为自发的放热反应。     

缬沙坦在丁酮-异丙醚混合溶剂中溶解度测定及关联

溶解度数据对结晶动力学研究及结晶器优化起到重要作用,利用静态平衡法测定了缬沙坦在丁酮-异丙醚混合溶剂中278.15—323.15 K的溶解度。结果表明:缬沙坦在混合溶剂中的溶解度,随着温度和丁酮摩尔分数的变大而变大,随着异丙醚摩尔分数的变大而变小。采用Modified Apelblat、一般多项式和hybrid方程对溶解度数据进行关联,平均相对偏差分别为0.95%,0.25%,3.64%,其中一般多项式方程关联较好。用van't Hoff分析计算了缬沙坦在溶解过程中的热力学参数(焓变、熵变和吉布斯自由能),表明溶解过程为自发吸热熵驱动过程。     

缬沙坦在乙酸乙酯中的溶解度及介稳区

采用静态平衡法测定缬沙坦在乙酸乙酯中278.15~323.15K的溶解度数据,利用Modified Apelblat、NRTL和λh方程分别对溶解度数据进行了关联,并通过van't Hoff分析计算了缬沙坦在溶解过程中的热力学参数（焓变、熵变和吉布斯自由能）。结果表明,缬沙坦在乙酸乙酯中的溶解度随着温度升高而显著增大,3个模型均具有较好的关联性,平均相对偏差分别为1.03%、3.87%、1.72%,Modified Apelblat方程对溶解度数据关联的效果最好;缬沙坦在乙酸乙酯中的溶解过程为自发吸热熵驱动过程,焓变在溶解过程中对吉布斯自由能贡献较大。利用激光法测定了缬沙坦在乙酸乙酯中的超溶解度,研究了不同搅拌速率、降温速率对结晶介稳区的影响。结果表明,随饱和温度的升高,介稳区显著变宽;搅拌速率越小、降温速率越快,介稳区越宽,降温速率的影响相对较小。     

喜树碱在二甲亚砜和甲醇(或乙醇)混合溶剂中溶解度的测定和关联

采用重量法测定了喜树碱(camptothecine,CPT)在二甲亚砜(dimethylsulfoxide,DMSO)+甲醇(或乙醇)混合溶剂中的溶解度,温度范围是274.50~326.00 K。在混合溶剂中CPT的溶解度随温度的升高而增大,随混合溶剂中DMSO摩尔分数含量的增大而增大。分别用修正Apelblat方程、λh方程和理想状态方程进行关联,关联效果令人满意,获得了相关模型参数。相对而言,λh方程关联的效果较好。根据溶解度数据和修正的Apelblat方程计算出溶解焓、溶解熵和吉布斯自由能。     

磷酸二氢钾在乙腈-水溶剂中溶解度的测定与关联

采用静态平衡法测定了293.15~318.15 K条件下磷酸二氢钾在乙腈-水溶剂中的溶解度,采用Apelblat模型对实验数据进行拟合,计算了磷酸二氢钾的溶解焓。结果表明：Apelblat模型能较好地关联磷酸二氢钾在乙腈-水溶剂中的溶解度,回归相关系数R²大于0.97;平均相对误差小于5%;在乙腈质量分数为0~0.838时,磷酸二氢钾的溶解焓为15.12~55.30 kJ/mol。得到了适用于磷酸二氢钾-乙腈-水体系的Apelblat模型,可为磷酸二氢钾的盐析结晶工艺提供热力学数据。     

Measurement and correlation of solubility and thermodynamic properties of N-acetyl-l-glutamine in some pure solvents and binary solvents at various temperatures

The solubility data of N-acetyl-l-glutamine in aqueous solution with different proportions of methanol and ethanol were determined with a static analytical method from 293.15 to 318.15?K. The data were then correlated by five models including the modified Apelblat equation, Van’t Hoff equation, local composition model (NRTL model), CNIBS/Redlich–Kister model, and Jouyban–Acree model. The results show that Van’t Hoff equation agrees well with the experimental data. When the ratio of methanol or ethanol in aqueous solution is in the range of 0.2–0.4, the solubility of N-acetyl-l-glutamine reaches its maximum. Besides, the melting temperature and fusion enthalpy of N-acetyl-l-glutamine were measured by the differential scanning calorimetry (DSC) and no polymorphism was found in the systems studied. The thermodynamic properties including enthalpy, entropy and Gibbs free energy during dissolution were calculated accordingly in this work.     

The solubility of cefquinome sulfate in pure and mixed solvents

Solid-liquid equilibrium data of cefquinome sulfate is important to develop industrial crystallization processes for cefquinome sulfate. The solubilities of cefquinome sulfate in five pure solvents (methanol, ethanol, ethylene glycol, acetic acid and water) from 277.15 to 305.15 K and in a binary acetone-water solvent from 278.15 to 293.15 K were measured at atmospheric pressure. The pure-solvent solubility data was correlated to the modified Apelblat and Van’t Hoff equations whereas the mixed-solvent system data was correlated to the modified Apelblat, Van’t Hoff, CNIBS/R-K and Jouyban- Acree models. It was found that the solubilities of cefquinome sulfate in all tested solvents decreased with the increasing of temperature. In addition, the thermodynamic properties of the dissolution processes, including standard Gibbs free energy, enthalpy and entropy changes, were calculated using the Van’t Hoff equation. It was found that the dissolution of cefquinome sulfate is exothermic.

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谷胱甘肽在水-乙醇混合溶剂中的溶解度测定及关联

采用称质量法测定了283.15～313.05 K下谷胱甘肽在不同配比的水-乙醇混合溶剂中的溶解度。实验结果表明,谷胱甘肽的溶解度随乙醇摩尔分数的增加而下降,随温度的升高而逐渐增大。分别用Apelblat简化方程和λh方程对溶解度数据进行关联,结果表明两种模型方程的回归效果均令人满意。利用van’t Hoff方程估算得到谷胱甘肽在水-乙醇中的溶解焓和溶解熵。两者均随乙醇摩尔分数的增加而增大。谷胱甘肽溶解度的测定及关联为其工业结晶过程设计和工艺优化提供理论依据,对工业生产具有重要的指导作用。     

赤藓糖醇在水中的结晶热力学及结晶过程研究

采用合成法测定了赤藓糖醇在水中的溶解度,并用修正的Apelblat方程和λh方程对其进行了关联,模型预测精度均可满足工业应用,采用修正的van’t Hoff方程和Apelblat方程计算了赤藓糖醇在水中的溶解焓、熵和吉布斯自由能;基于实验测定的结晶热力学数据,采用FBRM-PVM对赤藓糖醇冷却结晶过程进行了研究,研究结果为赤藓糖醇工业结晶过程的工艺优化和结晶设备的设计提供重要的基础数据。     

二硝酰胺盐溶解度的测定及拟合

为了研究适合二硝酰胺盐重结晶的溶剂,采用平衡法中的紫外分光光度法测试了3种二硝酰胺盐——脒基脲二硝酰胺盐(FOX-12)、二硝酰胺钾(KDN)和二硝酰胺铵(ADN)在不同溶剂中的溶解度;采用Apelblat方程与理想溶液模型拟合了溶解度数据;计算了二硝酰胺盐在不同溶剂中溶解时的热力学函数。结果表明,FOX-12在水中、KDN在乙醇水溶液中溶解度随温度变化明显,故水和乙醇水溶液可以分别作为FOX-12与KDN重结晶的溶剂;以乙醇作为溶剂时,由于存在氢键,故常温下ADN的溶解度大于10 g,而常温下FOX-12与KDN的溶解度小于1 g;Apelblat方程的拟合度(R 2)达到0.990以上,平均相对偏差(ARD)小于2%,表明Apelblat方程可以很好地关联溶解度数据。3种二硝酰胺盐在水、乙醇、异丙醇、乙醇水溶液、正丁醇中的溶解焓变和吉布斯自由能均为正值,表明溶解过程均为非自发的吸热过程。     

Solubility measurement and thermodynamic properties of sulfamonomethoxine in pure solvents and sulfamonomethoxine hydrate in acetone + water binary solvent at different temperature

The experimental solubility of sulfamonomethoxine in six different pure solvents (methanol,ethanol,1-propanol,l-butanol,ethyl acetate and acetone) and sulfamonomethoxine hydrate in acetone + water mixture solvents were measured from 294.55 K to 362.15 K by a laser dynamic method under atmospheric pressure.Experimental results indicated that the solubility data of sulfamonomethoxine increased with temperature increasing in pure solvents and the solubility followed this order:acetone ＞methanol ＞ ethanol ＞ ethyl acetate ＞ 1-propanol ＞ 1-butanol,but solubility in ethyl acetate was not affected significantly by temperature.In acetone + water mixture solvent,the solubility of sulfa-monomethoxine hydrate increased with temperature and the acetone concentration.Thermodynamic equations were applied to correlate solubility data of sulfamonomethoxine and sulfamonomethoxine hydrate including the modified Apelblat equation,λh equation,Wilson equation,NRTL equation,Van't Hoff-Jouyban Acree equation and modified Apel-Jouyban-Acree equation.Furthermore,thermodynamic properties △Gd,△Hd and △Sd of sulfamonomethoxine and sulfamonomethoxine hydrate in dissolution process were obtained and discussed with the modified Van't Hoff equation and Gibbs equation.     

Measurement and correlation of solubility of xylitol in binary water+ethanol solvent mixtures between 278.00 K and 323.00K

The solubility of xylitol in ethanol+water solvent mixtures was measured at temperatures ranging from 278.00 K to 323.00 K at atmospheric pressure by using a laser technique. The results of these measurements were correlated by the combined nearly ideal binary solvent CNIBS/Redlich-Kister equation. The experimental solubility and correlation equation in this work can be used as essential data and models in the purification process of xylitol. The variant 2 in the CNIBS/R-K models was confirmed to be more adaptable to predict solubility of xylitol in binary ethanol +water system. Using the experimentally measured solubilities, the thermodynamic properties of dissolution of xylitol, such as Gibbs energy, molar enthalpy of dissolution, and molar entropy of dissolution, were calculated.     

Experimental determination of solubilities and supersolubilities of 2,2′,4,4′,6,6′-hexanitrostilbene in different organic solvents

The laser monitor technique was used to determine solubilities and supersolubilities of HNS in N,N-dimethylformamide, dimethyl sulfoxide, acetonitrile, N-methyl-2-pyrrolidone and 1,4-butyrolactone. The experimental solubility values were correlated with λh equation, modified Apelblat equation and NRTL model. Furthermore, the dissolution enthalpy, dissolution entropy and the Gibbs energy of HNS were calculated by the experimental data. The results show that the solubilities of HNS in the above solvents increase with the increasing temperature. Besides, at the same temperature, the order of solubility is N-methyl-2-pyrrolidone dimethyl sulfoxide N,N-dimethylformamide 1,4-butyrolactone acetonitrile. The temperature dependence of predicted solubility is in agreement with the experimental data.     

Measurement of Disodium 5'‐Inosinate and Disodium 5'‐Guanylate in Aqueous Ethanol by Attenuated Total Reflection Ultraviolet Method

An online concentration monitoring method was established by using attenuated total reflection ultraviolet (ATR‐UV) coupled with a suitable partial least squares regression for a multi‐solute crystallization system, namely, disodium 5'‐inosinate (IMP) and disodium 5'‐guanylate (GMP) in aqueous ethanol. The results indicated that the established method accurately predicted the concentration of IMP and GMP in the solution. The solubility data was measured at various temperatures and ethanol/water mass ratios, and the experimental data was well correlated by applying the modified Apelblat equation and modified Jouyban‐Acree model. The implementation of cooling crystallization demonstrates that the developed calibration model is suitable for online concentration monitoring with reasonable accuracy and precision.