Partition Coefficients at Infinite Dilution from Flory-Huggins Theory

Abstract

An expression relating partition coefficients at infinite dilution to Flory-Huggins interaction parameters has been derived. The equation has been successfully applied to the partitioning of alcohols between water and cellulose acetate. The solvent-solute interaction parameter has a dominant effect on partition coefficients. For the systems studied, solvent-polymer interactions appear to be negligible.     

水、甲醇和乙醇溶剂在PVA膜材料中无限稀释扩散系数测定

用气相色谱法研究小分子溶剂与聚合物材料之间的相互作用是一种快速、准确和方便的方法,该方法可以测量多种小分子溶剂在聚合物中的溶解和扩散行为.采用该方法测定了水、甲醇、乙醇在固定液PVA中的保留时间和半峰宽,运用van Deemter模型进行数据处理,得到了上述几种小分子在PVA膜材料中的无限稀释扩散系数,获得了有意义的结果.     

An Alternative Method for Correlation and Evaluation of Mutual Diffusion Coefficients of Solutes in Organic Solvents at Infinite Dilution

Based on the linear free energy relationships theory and empirical equations, correlations of mutual diffusion coefficients of solutes in organic solvents at infinite dilution at various temperatures are proposed. Four homologues in 743 binary systems have been regressed and correlation equations for the diffusion coefficients are obtained. The mean relative deviations of the four equations are 8.63%, 8.57%, 2.96%, and 4.85%, and all of the squared correlation coefficients (R²) are larger than 0.96, indicating that the fittings are good. The results reveal that a simple form of the equation exhibits high estimation accuracy, definite theory meaning, wide applicability and wide temperature range. This study successfully combines macroscopic physical properties of substances with their molecular microstructure, providing an alternative approach for calculating of mutual diffusion coefficient.     

丙酮—环烷烃体系的无限稀释活度系数的气提法测定研究

如果溶剂是高挥发性物质,当用气提法测定无限稀释活度系数时需要加预饱和釜以消除气提时因溶剂量损失过大而带来的问题.本文就丙酮-甲基环戊烷、丙酮-环己烧和丙酮-甲基环己烷3个体系在298.2～318.2K温度范围内的γ~∞作了测定,用所得数据作全浓度范围的汽液平衡推算,与文献中实验值对比,发现Wilson方程结果最佳.     

五种不同类型土壤中有机化合物土壤吸附系数的预测

为了验证土壤柱液相色谱法测定农药的土壤吸附系数的普遍适用性和预测的准确性,采用了5种组成及性质差异较大、具有一定代表性的土壤样品,对在甲醇 水流动相条件下测定的保留因子与土壤吸附系数间的相关性进行了研究。结果表明,土壤柱液相色谱法是预测农药的土壤吸附系数的一种有效方法,适于多种类型土壤中农药土壤吸附系数的预测。     

非极性烷烃溶剂在聚乙烯膜中无限稀释扩散系数的测定

气相色谱法研究小分子溶剂与聚合物材料之间的相互作用是一种快速、准确、方便的方法,该方法可以用来研究多种小分子溶剂在聚合物中的溶解和扩散行为.通过气相色谱法测定了3种小分子烷烃溶剂(正庚烷、正壬烷和正癸烷)在固定液聚乙烯中的保留时间和半峰宽,用vanDeemter模型进行数据处理,得到3种小分子在聚乙烯膜中的无限稀释扩散系数.     

极性和非极性溶剂在聚乙烯中的无限稀释扩散系数的测定

 气相法研究小分子溶剂与高分子聚合物材料之间的相互作用是一个快速、准确、方便的方法 ,可以测量多种小分子溶剂在聚合物中的溶解、扩散参数。通过气相法测定了 5种小分子溶剂 (正己烷、正庚烷、正癸烷、乙醇和水 )在固定液聚乙烯中的保留时间和半峰宽 ,运用vanDeemter模型进行数据处理 ,得到上述 5种小分子在聚乙烯中的无限稀释扩散系数 ,获得了十分有意义的结果。     

Infinite Dilution Activity Coefficients and Gas-to-Liquid Partition Coefficients of Organic Solutes Dissolved in 1-Benzylpyridinium Bis(Trifluoromethylsulfonyl)Imide and 1-Cyclohexylmethyl-1-Methylpyrrolidinium Bis(Trifluoromethylsulfonyl)Imide

Infinite dilution activity coefficients and gas-to-ionic liquid partition coefficients were measured for a chemically diverse set of 48 or more organic solute probes dissolved in the ionic liquids 1-benzylpyridinium bis(trifluoromethylsulfonyl)imide ([BzPy][Tf₂N]) and 1-cyclohexylmethyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([ChxmPyrr][Tf₂N]) in the temperature range from 323.15 to 373.15 K using inverse gas chromatography. Selectivities and capacities for different separation problems were calculated from the measured chromatographic data. The measured partition coefficients were correlated using mathematical equations based on the Abraham general solvation parameter model. The derived Abraham model correlations back-calculated the observed partition coefficients to within 0.12 log₁₀ units.     

有机物在超临界二氧化碳中的无限稀释扩散系数的测定

利用经改造的超临界流体色谱仪测定不同温度和压力下苯、丙酮在超临界二氧化碳中的无限稀释扩散系数,开发出一个针对本科高年级学生的开放性实验,旨在加深学生对超临界流体及其性质的理解。在熟悉超临界流体色谱仪的工作原理、结构及其应用并掌握其操作方法的基础上,拓展学生视野和思维的深度及广度,提升学生的实验操作技能,培养高素质化学人才。     

三种芳烃溶剂在低密度聚乙烯膜材料中无限稀释扩散系数的测定

用气相色谱法测定了苯、甲苯和乙苯在固定液低密度聚乙烯中的保留时间和半峰宽,运用vanDeemter模型进行数据处理,得到3种芳烃小分子在低密度聚乙烯膜材料中的无限稀释扩散系数.     

Analysis of Fluorescent Compounds in Urine by Liquid Chromatography

Abstract

High speed separation of fluorescent compounds was examined. The retention time of 21 compounds was measured in two reversed phase modes and an ion-exchange mode liquid chromatography. Furthermore, urine samples of new-born babies, cancer patients and normal subjects were analyzed by the above systems. Several peaks were positively identified from the retention time, however there were many unknown fluorescent compounds. Among them, two peaks were found on the chromatograms in the reversed phase modes. These compounds were very polar and could not be identified, however the ratio of these peak height was used for classification of urine samples. Furthermore, indole-3-acetic acid and 5-hydroxyindole-3-acetic acid in urine were selectively analyzed on an ion-exchange resin with isocratic eluent after filtration.     

Determination of Carbonyl Compounds by High-Performance Liquid Chromatography

Carbonyl compounds in the form of 2,4-dinitrophenylhydrazones in alcoholic solutions were analyzed by high-performance liquid chromatography. This simple procedure is characterized by high sensitivity and reproducibility.     

气液色谱法测量芳烃在芳烃衍生物中的活度系数

用气液色谱法测量了C_6～C_8芳烃在芳烃衍生物中的无限稀活度系数。以Hildebrand-Scatchard-Flory-Huggins公式进行处理,得到了非极性或微极性溶剂的溶解度参数δ,以修正的Hildebrand-Scatchard-Flory-Huggins公式进行处理,得到了芳烃溶质与各极性溶剂相互作用常数ι_(12)。     

Simulated Moving-Bed Liquid Chromatography with Three Zones for Continuous Desalting of Organic Compounds

Aqueous solutions of DL-β-phenylalanine from a biotechnological process have been desalted by simulated moving bed preparative liquid-chromatography (SMB LC). During the design of a laboratory-scale continuous procedure four kinds of reversed-phase polymeric resin were compared. A suitable adsorbent was chosen and operating conditions were subsequently optimized by using equilibrium data obtained experimentally; productivity of the amino acid was used as the optimization target function. This enabled improvement of operating conditions determined in the first step of the procedure.