Temperature Dependent Solubility of α-Form L-Glutamic Acid in Selected Organic Solvents: Measurements and Thermodynamic Modeling
Temperature Dependent Solubility of α-Form L-Glutamic Acid in Selected Organic Solvents: Measurements and Thermodynamic Modeling
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DOI：
10.1021/ie200351b
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发表时间：
2011-07-06
影响因子：
4.2
通讯作者：
Du, Junqi
中科院分区：
文献类型：
--
作者：
Long, Bingwen;Li, Jing;Du, Junqi
采用静态分析法测定了α-型L-谷氨酸在甲醇、乙醇、正丙醇、丙酮、甲酸和二甲基亚砜（DMSO）6种有机溶剂中的溶解度。在278-355 K的温度范围内以约5 K的间隔进行测量，并通过重量法确定平衡浓度。结果表明，甲酸对α-谷氨酸的溶解度最高，其它溶剂的溶解度依次为水、丙酮、正丙醇、乙醇、甲醇、DMSO、乙酸。估算了L-谷氨酸的假设熔化焓和熔化温度。几种常用的热力学模型，包括经验范特霍夫方程和威尔逊，NRTL，和UNIQUAC方程，应用于关联的实验溶解度数据。发现上述模型的二元相互作用参数与温度呈线性关系，并回归了相关系数。结果表明，所有模型均能较好地再现实验溶解度，UNIQUAC方程的关联结果最好，总标准偏差为2.7 × 10 ~（-5）。
In this study the solubility of a-form L-glutamic acid in the six organic solvents methanol, ethanol, 1-propanol, acetone, formic acid, and dimethyl sulfoxide (DMSO) was measured by a static analytic method. The measurements were carried out over the temperature range 278-355 K at around 5 K intervals, and the equilibrium concentration was determined by the gravimetric method. The experimental results show that formic acid has the highest solubility to a-form L-glutamic acid while the other solvents have the solubility order water, acetone, 1-propanol, ethanol, methanol, DMSO, and acetic acid. The hypothetical enthalpy of fusion and melting temperature of L-glutamic acid are estimated. Several commonly used thermodynamic models, including the empirical van't Hoff equation and the Wilson, NRTL, and UNIQUAC equations, were applied to correlate the experimental solubility data. The binary interaction parameters of the above models are found to have a linear dependency on temperature, and the coefficients were regressed. It was found that all these models can satisfactorily reproduce the experimental solubility and the UNIQUAC equation can provide the best correlation results with an overall standard deviation of 2.7 x 10(-5).