Solubilities of vegetable oils in aqueous ethanol and ethanol-hexane mixtures

Summary The solubility of vegetable oils in aqueous ethanol depends on the concentration of alcohol and temperature of the system. At ordinary temperatures even absolute alcohol is not a good solvent for vegetable oils since the solubility is even less than 10 g. of oil per 100 g. of alcohol. Mowrah, safflower, peanut, and cottonseed oils are soluble in absolute alcohol at 70°C. All the oils investigated are found to be miscible above the boiling point of alcohol even if the concentration is 98%. In 95% ethanol they are miscible between 90° and 100°C. Addition of a good solvent, like n-hexane, increases the solubility of oils, and the solubility temperatures are lowered. From the results obtained by various methods of solubility determination it is found that the apparatus employed in the present work yields more reliable results by eliminating the visual observation of turbidity temperatures, ensuring vigorous stirring and allowing sufficient amount of time to attain equilibrium conditions in determining the solubilities of vegetable oils. Presented at fall meeting, American Oil Chemists' Society, Cincinnati, O., September, 30–October 2, 1957.     

Alcoholic extraction of vegetable oils. II. Solubilities of corn,linseed, and tung oils in aqueous ethanol

Summary Solubilities of corn, linseed, and tung oils in aqueous alcoholic solutions at various temperatures have been determined by a direct and simple method. The solubility curves for the three oils in aqueous alcoholic solutions are presented. The critical solution temperatureversus alcohol composition data have been plotted for the three oils. It is observed that the critical solution temperature increases with the water content of the alcohol and that the relationship is linear in each case. Similar results were obtained for cottonseed, peanut, sesame, and soybean oils previously (1). The pressure in the system, increases with temperature; the maximum is approximately 20 p.s.i.g. Presented at the Philadelphia fall meeting, American Oil Chemists’ Society, October 11, 1955.     

Alcoholic extraction of vegetable oils. I. Solubilities of cottonseed,peanut, sesame,and soybean oils in aqueous ethanol

Summary Solubilities of cottonseed, peanut, sesame, and soybean oils in aqueous alcoholic solutions at various temperatures were determined directly. Solubility curves for the four oils in aqueous alcoholic solutions are presented. The critical solution temperaturesversus alcoholic concentrations data have been plotted and are in complete agreement with the previously published data of Japanese workers in each case. It is observed that the critical solution temperature increases with the moisture content of the alcohol, and in each case the relationship is linear. The pressure in the system also varies directly with the temperature, the maximum being approximately 20 p.s.i.g.     

Effect of ethanol on plasma triglycerides in male and female rats

A single large dose of ethanol was given to fasted rats and to rats fed a fat-free diet containing orotic acid. An increased plasma triglyceride concentration after ethanol feeding was consistently found in fasted male rats, while the results in fasted female rats varied between the experiments. The total rate of triglyceride secretion into the plasma in fasted rats was estimated as the Triton-induced hypertriglyceridemia 6–7.5 hr after ethanol feeding. The effect of ethanol on the triglyceride secretion from extrahepatic sources was estimated in the same way in rats, with the hepatic triglyceride secretion blocked by orotic acid. Ethanol enhanced the Triton-induced hypertriglyceridemia in both male and female fasted rats, but to a greater extent in male rats. Ethanol did not stimulate the extrahepatic triglyceride secretion during this period.     

Solubilities of solanesol in acetonitrile,ethanol and n-hexane from 285 to 310K

Using a laser monitoring observation technique, we measured the solubilities of solanesol in acetonitrile, ethyl alcohol and n-hexane by a synthetic method at temperatures ranging from 285 to 310 K at atmospheric pressure. Empirical equations were proposed and the calculated results show good agreement with the experimental solubilities.     

Alcoholic extraction of vegetable oils. III. Solubilities of babassu,coconut, olive,palm, rapeseed,and sunflower seed oils in aqueous ethanol

Summary Solubilities of babassu, coconut, olive, palm, rapeseed, and sunflower seed oils in aqueous alcoholic solutions at various temperatures were determined by a direct and simple method. Solubility curves for the six oils are presented. The critical solution temperatures increase with the water content of the alcohol, and in each case the relationship is linear. The pressure in the system also varies with the temperature, the maximum being about 20 p.s.i.g.     

Solubilities and diffusivities of N2O and CO2 in aqueous sulfolane solutions

The solubilities of N₂O and CO₂ in aqueous sulfolane solutions and pure sulfolane solvent, and the diffusivities of N₂O in aqueous sulfolane solutions were measured and correlated over the temperature range from 20° to 85°C; also, the data for density and viscosity that were needed in this experimental work were measured. This experiment revealed that the parameter of N₂O analogy method depends not only on the temperature, but also on the character of the solvent. Therefore, different solvents possess different analogy parameters. Only for dilute aqueous solutions can the parameter be replaced by the analogy parameter of water. The results also proved that the sum of volume fractions contribution is a simple method to estimate the solubility in aqueous sulfolane solutions over the whole range of the concentrations and experimental temperatures, with an average deviation of less than 4·0%.     

Growth rates of ibuprofen crystals grown from ethanol and aqueous ethanol

To quantify the crystallization of racemic ibuprofen [2-(4-isobutyl-phenyl)-propionic acid] from aqueous ethanol it is necessary to know the growth rate kinetics. Growth rates were measured by adding SPG (size proportional growth) seed crystals to an isothermal non-nucleating batch crystallization and sampling during the batch. The supersaturation was measured by refractive index and the crystal size by laser light scattering (Malvern). To ensure the batch was non-nucleating the supersaturation was kept within the narrow secondary MZ (metastable zone). Measurements were made at three temperatures, 10, 25 and 40 °C. The growth rate was proportional (first order kinetics) to the solution supersaturation, expressed in mass ratio of ibuprofen to ethanol units. Despite the narrow MZ, the initial growth rates were substantial (up to 1 μm/min). Temperature has a large effect on growth rate with an activation energy of 13.7 kJ/mol. The water content affects the growth rate coefficient differently depending on the temperature.     

Alcoholic extraction of vegetable oils. Part IV. Solubilities of vegetable oils in aqueous 2-propanol

Summary Solubilities of 14 vegetable oils in four different concentrations of aqueous 2-propanol at various temperatures were determined by a direct and simple method. Comprehensive solubility data of these oils and the critical solution temperatureversus 2-propanol composition data are presented in tabular form. Solubility of each oil in aqueous 2-propanol increases with temperature until the critical solution temperature is reached, at and above which oil and the solvent are miscible in all proportions. Further the critical solution temperatures of all the oils with aqueous 2-propanol solutions increased with the increase in water content of 2-propanol solutions. There appears to be a general relation between fatty acid contents of the oils and critical solution temperatures which needs further study. Presented at the 30th fall meeting, American Oil Chemists' Society, September 24–26, 1956, Chicago, Ill.     

Supercritical fluid extraction of ethanol from aqueous solutions

The recovery of ethanol from aqueous solutions was studied by using supercritical carbon dioxide. At 333.2 K and 10.0 MPa, vapor–liquid equilibrium data of the mixture CO₂+ethanol+water were determined. No azeotrope was observed. Theoretical calculation of equilibrium stages was performed and compared with countercurrent column experiments. Separation of extract and solvent was optimized by multistage solvent distillation. The height of one theoretical stage was found to depend on the ethanol content of the liquid phase. Moreover, flooding point measurements were carried out with ethanol+water mixtures of different composition.     

Fractionation of crude soybean lecithin with aqueous ethanol

Aqueous ethanol was used to fractionate soybean PC and PI, which have dissimilar solubilities in this solvent. The effects of oil and moisture contents of the crude lecithin, ethanol-to-lecithin ratio, and dispersion temperature on the efficiency of phospholipid (PL) fractionation were investigated. Yield, purity, recovery, and PL class composition were examined. Yield was defined as the amount of fractionated material, divided by the acetone-insoluble (AI) matter in the starting material; purity was the percentage of PL (PC+PE+PI) as quantified by HPLC in the fraction; and recovery was the amount of PL quantified relative to the quantity of AI matter. Higher oil contents significantly increased the yield of the PC fraction, but they significantly decreased yield, purity, and recovery of the PI fraction. They also significantly affected the PL composition of the PC fraction. Higher moisture contents significantly decreased the yield but slightly increased the purity of PC fractions. Higher temperatures significantly increased the yield and recovery of the PC fraction. They also affected the relative proportion of PL classes in the PC and PI fractions. The ethanol-to-lecithin ratio significantly affected yield, purity, and recovery as well as the relative proportions of PL in both PC and PI fractions. A combination of multiple fractionation and high-low temperature treatment was also examined. Fractionating twice with ethanol increased the purity of the PC fraction. High-low temperature fractionation increased the purity and PC percentage in the PC fraction.     

超临界流体萃取的平衡溶解度

由溶剂化缔合观点,推导出了计算难挥发物质在超临界流体(SCF)中平衡溶解度的缔合模型.利用文献数据对缔合模型的适用性进行了考察,得到了较满意的结果.以缔合模型为基础,对SCF的溶解能力及其随诸因素影响的变化规律进行了分析和讨论,由此得出的一些推论均能和实验现象一致.     

An aqueous ethanol extraction process for cottonseed oil

A bench-top process for the extraction of cottonseed flakes with aqueous ethanol has been developed. The process consists of cottonseed meat flaking, drying and extraction with boiling, aqueous ethanol (95% by volume) at atmospheric pressure. The resulting miscella is chilled, producing free oil, emulsified oil and mucilaginous gum. The heterogeneous solution is processed through a phase separator where free and emulsified oil and gum are separated from oil-lean miscella. The oil and gum phases are treated with caustic soda and centrifuged to produce semirefined oil containing about 4% volatiles. The miscella phase, containing about 3.3% lipid-like material and 1% petroleum ether insolubles, is reheated and recycled to the extractor. After the marc is pressed foots are added, and it is desolventized to produce a meal having a residual oil content less than 1%. Although not yet otpimized, the process shows potential for scaleup to pilot plant processing and adaptability to current oil mill solvent operations. Presented at the AOCS annual meeting, Chicago, May 1983.     

Solubilities of solids in supercritical fluids

The solubilities of several low-volatility compounds in supercritical fluids were measured. The fluids used were pure carbon dioxide or carbon dioxide modified with small amounts of organic liquids. Some enthalpies of solution of solids in carbon dioxide at a density of 0.80 g/mL are presented. The enthalpy of solution of fluoranthene in carbon dioxide was found to be less endothermic at higher CO₂ density. The order of solubilities in the modified fluids was the same as that in the pure liquid modifiers. The same apparatus was used to measure vapor pressures of some substances as well as solubilities.     

Hepatic origin of triglycerides in fatty livers produced by the continuous intragastric infusion of an ethanol diet

Male Wistar rats were maintained for 30 days on an independent and continuous intragastric infusion of ethanol and nutritionally defined liquid diet containing only a small amount of corn oil (CO-4.9% calories). Ethanol intake was progressively increased from 32% to 40.4% of the total calories to maintain a high degree of intoxication during this period. Rats in the control group were infused with an isocaloric diet in which alcohol was replaced by dextrose. The liver triglyceride (TG) content of rats given alcohol (61.5±16.4 mg/g) was ca. 10-fold greater than that of controls (5.9±2.1 mg/g) and similar to that observed previously in rats fed an ethanol diet containing high levels of fat (35% and 43% calories). In TG of fatty liver, the level of 18∶2 was small (3%), even though CO in the diet contained a high level of this acid. Furthermore, 16∶1 and 16∶0 contents were markedly elevated (16% and 40%, respectively) despite the fact that CO did not contain 16∶1 and had only a small amount of 16∶0. Liver TG having a fatty acid (FA) composition markedly different from that of CO and the presence of high levels of 16∶1 and 16∶0 indicate that the TG accumulated in the fatty liver originated from hepatic lipogenesis rather than from dietary fat.     

Plasticization of chitosan membrane for pervaporation of aqueous ethanol solution

The process of pervaporation in which two components diffuse through a nonporous polymer membrane was modelled when one of the penetrants can exert a plasticization action to the membrane material. Thereat a phenomenological model was employed for describing the plasticization effect on the diffusivities for penetrants in the membrane. The sorption equilibria and permeation fluxes for aqueous ethanol solutions in a chitosan membrane were measured, and the permeation fluxes for water were compared with those predicted by the proposed model. The concentration of sorbed water was linear with its weight fraction (x₄) in the feed solution, whereas the permeation flux of water was. affected by the plasticization action of sorbed water to the polymer. This plasticization effect on the diffusion process can be simulated in terms of the proposed phenomenological model.     

Polarographic reduction of pyrithioxine in aqueous buffers containing 5% of ethanol

The electroreduction of the cerebral metabolism activator pyrithioxine [3 3′-(dithio dimethylen) bis 5-hydroxy 6-methyl 4-pyridine methanol] was studied by dc and dp polarography in boric acid-free aqueous buffers containing 5% of ethanol. Over the pH range 2.0–9.0, one ave, A, or two waves, B and A, were obtained depening of the pyrithioxine concentration. B is characterized as a “main wave” and A as a Brdicka adsorption post-wave. At pH > 10, two waves, A′ and B′, were obtained, A′ displaying an adsorption-kinetic character. The mechanism of the electrode process in both pH ranges has been reduced from the dependence of the wave characteristics upon pH and from the results obtained by scan-direct and scan-reversal normal pulse polarography, cyclic voltammetry and uv spectroscopy.     

MBr(M=Na,K)在离子液体[Bmim]Br水溶液中的溶解度

为探索溴化1-丁基-3-甲基咪唑([Bmim]Br)离子液体对无机溴化物MBr(M=Na,K)在水中溶解度的影响,采用等温溶解平衡法在常压下测定了298.15~328.15 K范围内MBr在[Bmim]Br(1)+H₂O(2)溶液中的溶解度,考察了离子液体含量对溶解度的影响。实验结果表明,[Bmim]Br的加入会显著降低MBr(M=Na,K)在水中的溶解度,离子液体[Bmim]Br对KBr的盐析作用比对NaBr的盐析作用大。不同温度下的溶解度数据可用Pitzer混合电解质溶液模型进行关联,得到了混合离子相互作用参数以及MBr在混合溶剂中的平均活度因子和溶剂的渗透系数。模型计算的溶解度与实验结果吻合良好,平均活度因子和溶剂的渗透系数均随离子液体含量的增加而增加。     

液液萃取技术在低浓度乙醇水溶液样品检测前处理中的应用

采用液液萃取技术浓缩水中的低浓度乙醇后,用气相色谱法进行测定。首先优化以甲基叔丁基醚(MTBE)为萃取剂的萃取条件:初始乙醇溶液的质量分数win=1.032%、水相与有机相的体积比5∶1,萃取温度291.2 K,搅拌速度为200 r/min.在此基础上,分别加入固体无机盐和离子液体强化液液萃取过程,结果表明固体无机盐K2CO3的盐效应最为明显;随着盐浓度的增加,萃取后有机相中乙醇的质量分数wo也随之增大,从而实现对乙醇水溶液的显著浓缩作用。盐效应的分离机理进一步通过红外光谱分析和量子化学计算,从分子结构和分子间相互作用力方面进行解释,因而实验、理论分析和计算结果保持一致。该样品检测前处理方法具有重现性好、准确度高、快速、简便的特点,且无工业放大效应,为分析水中低浓度有机物提供参考价值。本文中将化工分离过程强化技术应用于样品检测前处理中,体现了化学工程与分析化学的跨学科结合。