双水相萃取技术研究现状

近年来,双水相萃取(ATPE)已经发展成由计算机控制、在常规萃取设备中、能连续操作的分离技术。介绍了传统双水相体系(ATPS)和新型ATPS的特征、分相机理、工业应用的优缺点,指出寻找低成本易回收可循环利用的ATPS组成物质和对预分离物质有更高选择性的ATPS组成物质是研发新型ATPS的方向。论述了ATPS液液平衡的热力学模型、分配系数的关联方法,指出提高选择性及分离效率是ATPE应用研究的方向,指出总结分配系数影响因素规律、修正液液平衡的热力学模型是ATPE理论研究的方向。     

双水相体系萃取木瓜蛋白酶的研究

采用聚乙二醇(PEG)/(NH4)2SO4双水相体系对木瓜蛋白酶进行萃取分离,研究了PEG相对分子量、PEG质量分数、(NH4)2SO4质量分数和pH值对木瓜蛋白酶分配系数及酶活力回收率的影响.结果表明,最佳萃取条件为:PEG4000质量分数6%、(NH4)2SO4质量分数18%、pH值6.0,在此条件下,木瓜蛋白酶的...     

双水相体系酶法合成L-苯丙氨酸的研究

以天冬氨酸转氨酶为催化剂,开展了双水相体系中苯丙酮酸转氨反应制备L-苯丙氨酸的研究。双水相体系质量组成为聚乙二醇4 000(20%)/Na2HPO4(16%)。苯丙酮酸钠盐、细胞和L-苯丙氨酸在双水相体系中的分配系数分别为8.03,31.7和0.74。当底物浓度为43.4 g/L时,该体系酶法合成L-苯丙氨酸得率为78.1%,比在水溶液体系中提高了27.4%。     

Extraction of Puerarin using Ionic Liquid Based Aqueous Two-Phase Systems

Various ionic liquid-based aqueous two-phase systems (IL-ATPS) were evaluated to extract puerarin. The results indicated that the nature of ILs, the salting-out ability of salt, and the acidity and basicity of the salt-rich solution had important influence on the extraction efficiency. Various factors were optimized systematically, that is, the amount of IL, salt, puerarin, and short-chain alcohol. Under the optimal experimental conditions (the amount of K₂HPO₄ 0.30–0.42 g/mL, [Bmim]Br 0.30–0.36 g/mL and 1.0 mL puerarin stock solution), the extraction efficiency of puerarin was over 99% by a single-step extraction, which indicated that the evaluated IL-ATPS was a prospective extraction medium. Finally, the IL-ATPS was successfully used to extract puerarin from Radix Puerariae Lobatae extracts.     

Tunable Aqueous Polymer Phase Impregnated Resins: A Combination of the Extractant Impregnated Resin Principle and Aqueous Two-Phase Systems

This scientific note introduces a concept supposed to enhance aqueous two-phase extraction by immobilizing one of the two phases of an aqueous two-phase system in porous particles. This approach, developed by the author, is based on solvent impregnated resins. The resulting so-called (tunable) aqueous polymer phase impregnated resins might avoid drawbacks of aqueous two-phase extraction, such as long phase separation times due to persistent emulsification. Due to the novelty of the idea and resulting current lack of fundamental studies, the idea is put up to discussion in order to initiate scientific exchange and hopefully widespread investigation of its true potential.     

Phase Behavior of Ionic Liquid-Based Aqueous Two-Phase Systems

As an environmentally friendly separation medium, the ionic liquid (IL)-based aqueous two-phase system (ATPS) is attracting long-term attention from a growing number of scientists and engineers. Phase equilibrium data of IL-based ATPSs are an important basis for the design and optimization of chemical reactions and separation processes involving ILs. This article provides the recent significant progress that has been made in the field and highlights the possible directions of future developments. The effects of each component (such as salting-out agents and ILs) on the phase behavior of IL-based ATPSs are summarized and discussed in detail. We mainly focus on the phase behavior of ATPSs by using ILs, expecting to provide meaningful and valuable information that may promote further research and application.     

双水相萃取技术的应用进展

主要介绍了双水相萃取的基本要点及应用特点,综述了近三年来双水相萃取技术在生物工程、药物成分提取分离、环境中有害物分离测定及与其它方法配合使用等方面的应用,探讨了双水相萃取技术的应用前景.     

Separation and Purification of Aloe Anthraquinones Using PEG/Salt Aqueous Two-Phase System

The anthraquinones were extracted from Curacao aloe leaves. Aqueous two-phase system (ATPS) of polyethylene glycol (PEG)/salt, coupled with spectrophotometry and high performance liquid chromatography (HPLC) were employed for the first time as an attractive alternative for the downstream processing of aloe anthraquinones, mainly for the removal of the impurities without additional steps. The influence factors such as molecular mass and concentration of PEG, type, and concentration of neutral salt, temperature, and pH on the phase partition behavior of ATPS had been studied. Under the optimal condition, the highest extraction yield 90.54% was obtained in PEG phase using PEG-6000/(NH₄)₂SO₄ system to a mass ratio of 2:1 at 40°C, pH 3.0 with 0.6 g sodium chloride added. The reverse extraction of anthraquinones from the PEG phase was achieved with a recovery of 70.15% by adjusting the pH. Meanwhile, the PEG could be recycled. The major components in aloe anthraquinones of aloe-emodin and chrysophanol were analyzed by HPLC before and after ATPS extraction process. Compared with conventional purification methods, this technique can be completed in one operation; besides it is low-cost and environmentally friendly.     

双水相分配技术提取生物小分子的进展

近来，双水相分配技术愈来愈受到人们的关注，评述了用这项技术提取生物小分子的最新进展。考察了聚合物分子量及其分布，盐种类，结线长度，相比及添加剂对生物物质在双水相系统中分配的影响，还进行了模拟料液与不同批次发酵液的对比实验。探讨了生物小分子在双水相系统中的分配机理。     

离子液体双水相萃取山楂黄酮和多糖的研究

采用分光光度法研究了山楂黄酮和多糖在[Bmim]BF4/(NH4)2SO4双水相体系的分配行为,探讨了离子液体浓度、(NH4)2SO4浓度、山楂用量和超声时间等因素对山楂黄酮和多糖萃取率的影响。确定最佳萃取条件为:离子液体[Bmim]BF4浓度0.26~0.30g·mL-1,(NH4)2SO4浓度0.08~0.10g·mL-1,山楂用量0.14~0.17g,超声时间15~20min,在此优化条件下,双水相上相中黄酮的萃取率为86.4%~96.0%、下相中多糖的萃取率为75.2%~76.0%。     

两种双水相体系提取枇杷叶中黄酮的工艺研究

以枇杷叶为原料,利用双水相体系提取黄酮。考察了聚乙二醇-硫酸铵体系和乙醇-硫酸铵体系中各物质用量、料液比(g∶mL,下同)、pH值、提取温度、提取时间等条件对提取效率的影响,并对两种体系的提取效率进行了比较。结果表明:聚乙二醇-硫酸铵体系中,在聚乙二醇用量为2.0g、硫酸铵用量为1.5g、料液比为0.3∶10、pH值为9、提取温度为40℃、提取时间为1.5h的条件下,提取效率最高,达5.80%;乙醇-硫酸铵体系中,在无水乙醇用量为4.0mL、硫酸铵用量为1.8g、料液比为0.2∶10、提取温度为40℃、提取时间为1.0h的条件下,提取效率最高,达7.49%;可见乙醇-硫酸铵体系的黄酮提取效率高于聚乙二醇-硫酸铵体系。     

双水相萃取技术及其在药物分离中的应用

双水相萃取技术作为一种新型的分离技术用于药物提取分离具有广阔前景。介绍了双水相体系的组成,双水相萃取技术原理、工艺过程、应用等。     

Thermoseparating Aqueous Two-Phase System for the Separation of Alkaline Proteases from Fish Viscera

The objective of this study was to isolate alkaline proteases from farmed giant catfish viscera by using a thermoseparating aqueous two-phase system (T-ATPS). Different phase partitioning parameters—type of salts, NaCl addition, and temperature—were optimized. The optimum system contained 40% EOPO3900-10% MgSO₄ with 17%NaCl, induced phase separation at 55°C, and provided the highest recovery (77.98 %) and purity (PF: 21.50-fold) with a partition coefficient (K_E) of 11.90 and a volume ratio (V_R) of 0.19. In the recycling step, the mixture of the bottom salt-rich phase and bottom EOPO-rich phase in the ratio of 0.5:1.5 (w/w) provided the highest recovery and purity. Hence, the total recovery of 91.62% was obtained from the separation system. Three major clear zones (24, 36, and 130 kDa) can be distinctively observed on casein-substrate gel electrophoresis for protease activity staining. Major protein components of perilla seed hydrolysates were completely hydrolyzed by the alkaline proteases at 70 units while those of red kidney bean isolate were more resistant to protein hydrolysis. Fifty units of Flavourzyme® hydrolyzed completely both plant proteins into small peptides or amino acids. As a result, T-ATPS could be used as an alternative method for the separation of enzymes from various sources with acceptable recovery. In addition, the obtained alkaline proteases can be further used in preparation of protein hydrolysates.     

Extraction and Recovery of Rutin from Acerola Waste using Alcohol-Salt-Based Aqueous Two-Phase Systems

Extraction of rutin from acerola waste was investigated using alcohol-salt-based aqueous two-phase systems (ATPS). Initially, the partitioning was studied using model systems with pure and commercial rutin. The impact of the ATPS constituents and composition, initial amount of rutin, temperature and addition of electrolytes was evaluated. Rutin can be recovered either in the alcohol-or-salt-rich phase depending on the salt used. To validate the optimization process, rutin extraction from acerola waste was carried out further. The results obtained with the real samples are in close agreement with the model systems and validate the optimization tests and support their applicability in bioresource-related processes.     

高稳定性双水相共聚物PAM-AMPS的合成与表征

采用双水相聚合技术,以硫酸铵水溶液为反应介质,过硫酸铵和亚硫酸氢钠氧化还原体系为引发剂,丙烯酰胺(AM)和2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为反应单体,聚2-丙烯酰胺基-2-甲基丙磺酸(PAMPS)为稳定剂,制备了稳定的阴离子聚丙烯酰胺(PAM-AMPS)双水相分散液。采用FTIR、XRD、TG及DTA对产物进行了表征,并对其分散液进行了TEM与稳定性分析。结果表明:共聚物PAM-AMPS为无定形态的非晶聚合物,且热稳定性好;PAM-AMPS双水相分散液稳定性能优良,动力学不稳定指数(TSI)≤0.4,分散相为球形或椭球形液滴,平均粒径为186.2 nm。流变测试显示:ρ(NaCl)=2×10~4mg/L时,PAM-AMPS双水相分散液质量分数(以体系总质量计,下同)从0.2%增至1%,该混合体系黏度从8.22 Pa·s增到60.74 Pa·s;NaCl质量浓度从1×10~4mg/L增至5×10~4mg/L时,含质量分数0.2%的PAM-AMPS双水相分散液的混合体系黏度从10.80 Pa·s降至5.94 Pa·s。因而PAM-AMPS双水相分散液表现出优良的稠化及耐盐性能。     

Aqueous Two-Phase Extraction of Lactic Acid: Optimization by Response Surface Methodology

In this study a suitable alcohol/salt aqueous two-phase (ATP) system was selected for the recovery of lactic acid from an aqueous solution. From the different ATP systems studied, the ethanol/dipotassium hydrogen phosphate ATP system appeared to be favorable. To examine the potential of this ATP system, the extraction yield of lactic acid in aqueous solutions was optimized with the response surface methodology. The parameters studied were concentrations of ethanol (22.00–38.80%, w/w), dipotassium hydrogen phosphate (15.00–31.80%, w/w) and lactic acid (26.36–93.64 g/L). The optimum conditions were found to be 30.23% w/w ethanol, 18.40% w/w dipotassium hydrogen phosphate, and 80 g/L lactic acid. Under these conditions, a favorable extraction yield of lactic acid was obtained. The maximum partition coefficient of lactic acid and extraction yield was determined as 2.26 and 87%, respectively. The optimum extraction conditions were then used to guide the recovery of lactic acid from a real fermentation broth. As a result, the partition coefficient and extraction yield of lactic acid reached 2.06–80%, respectively.     

Predicting Partitioning in Aqueous Two-Phase Systems and the Effects of Temperature Changes

Abstract

The use of aqueous two-phase extraction can be attractive for some separations, but the choice of such systems is frequently done in an empirical manner. Predictive models are needed for optimal design, but previous ones appear to have limitations. In addition, these systems have usually been used previously at temperatures around 25°C; however, it is possible that better separations may be achieved at other temperatures. An equation is developed here which can predict partitioning for a wide range of solutes. The effect of temperature on partitioning has been determined, and this can also be predicted by using the equation. Thus, this model may prove quite useful in designing and optimizing extractive separations.

     

Partitioning of Propionic Acid in Polyethylene Glycol/ Different Salts of Sulfate Aqueous Two-Phase Systems

The extraction of propionic acid has been studied by liquid–liquid extraction with poly ethylene glycol /different salts of sulfate aqueous two-phase system (ATPS). In this study, a multilevel factorial design was applied to evaluate the effects of four independent variables (PEG molecular weight, type of salt, salt concentration, and temperature) on propionic acid extraction yield. The statistical significance of each factor was evaluated by an analysis of variance. The results indicated that the type and concentration of salt were the major contributing factors to propionic acid extraction. The PEG4000/ MnSO₄ system was suitable for the extraction of propionic acid from dilute water.     

Application of Water-Miscible Alcohol-Based Aqueous Two-Phase Systems for Extraction of Dyes

The water-miscible alcohols (ethanol, 1-propanpol, 2-propanol) were used to form aqueous two-phase systems with K₂HPO₄ and Na₂HPO₄. Meanwhile, the organic citrates were also investigated as the phase-separation salts. The effects of the types and concentrations of phase-forming substances as well as temperature on the formation of aqueous two-phase systems were discussed. The alcohol (ethanol, 1-propanpol, 2-propanol)–salt (K₂HPO₄, K₃C₆H₅O₇, (NH₄)₃C₆H₅O₇) aqueous two-phase systems were used to extract Rhodamine B and methyl orange in aqueous solution. It proved that the water-miscible alcohol–salt (inorganic salt, organic salt) aqueous two-phase systems can be both used to extract hydrophilic targets directly without adding any reaction reagents. The aqueous two-phase extraction process was also discussed.     

Production of Alkaline Protease by Bacillus thuringiensis H 14 in Aqueous Two-Phase Systems

Alkaline protease production by Bacillus thuringiensis H 14 was studied in aqueous two-phase systems composed of PEG X (X = 9000, 6000, 4000) and potassium phosphate. The top phase is continuous and rich in PEG while the bottom phase is dispersed and is rich in phosphate, microbial cells being mainly retained in the bottom phase. The alkaline protease produced during fermentation, partitioned into the upper phase (about 80%) and total protease produced were about 2·80 and 2·26 times higher than that of homogeneous fermentation when the fermentations were carried out in aqueous two-phase systems from the beginning and made after 45 h of inoculation respectively. © 1997 SCI.