Potassium Phosphate Salts-Based Aqueous Two-Phase Systems Applied in the Extraction of Gallic Acid from Guava

Aqueous two-phase systems (ATPS) consisting of potassium phosphate salt + alcohol or polyethylene glycol were investigated to extract gallic acid. The partitioning process was studied using purity gallic acid (GA). The constituents either promote the partition process of GA to bottom or top phase, leading to the creation of versatile systems. The salt acts as a drive force of process because it influences the value of phase pH, and consequently the deprotonation of biomolecule and its partition. The results using GA from guava are in close agreement with the model systems, validating the experimental data and supporting their applicability in real systems.     

Affinity Partitioning of Metal Ions in Aqueous Polyethylene Glycol/Salt Two-Phase Systems with PEG-Modified Chelators

Abstract

The systematic partitioning of metal ions in the presence of polyethylene glycol (PEG) chelate derivatives in PEG/salt two-phase systems is described. Results show that the partitioning is enhanced significantly, and this effect is apparently based on the characteristics of binding of the chelate and the nature of the metal ion in addition to the effect of the attached PEG molecule. Previous work with PEG-iminodiacetic acid has been extended with the chelating derivatives PEG-TED [tris(carboxymethyl)ethylene diamine], PEG-TREN-Cm [carboxy-methylated-tris(2-aminoethyl)amine], and PEG-ASP (aspartic acid). Their effectiveness to selectively partition the metal ions is demonstrated and discussed. The partition experiments were performed using two-phase systems of PEG (8000 MW), sodium sulfate, the PEG-chelating derivatives, and different concentrations of copper, nickel, and cobalt as model metal ions. Partition coefficients (ratio of top to bottom metal concentrations) greater than 1 were obtained for the metal ions with all the chelating derivatives tested. Selective enhancement of partitioning was observed in all cases. Based on the experimental results and theoretical principles, the method shows potential as an alternative mode to remove efficiently and selectively metal ions from solutions using aqueous two-phase systems and PEG-chelate derivatives.     

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。     

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。     

Partitioning Behavior of Tetracycline in Hydrophilic Ionic Liquids Two-Phase Systems

Ionic liquids-based aqueous two-phase system (ILs-ATPS) offers an alternative approach for the extraction of tetracycline (TC) through their partitioning between two phases. The procedure was composed of 1-butyl-3-methylimidazolium halide ([Bmim]X(X = Cl, Br)) and K₂HPO₄ using a liquid-liquid extraction technique. The influence factors on partition behavior of TC were optimized systematically, including the quality of salts and IL, the amount of TC, pH value, and temperature. The maximum extraction efficiency of TC could reach 99%. The interactions between the ATPS and TC have been examined by isothermal titration calorimetry. Extraction of antibiotics TC using ILs-ATPS could achieve nearly complete extractions in a single-step by way of the proper tailoring of their concentrations in the aqueous media.     

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.     

双水相萃取废液中成相物质聚乙二醇的回收利用

研究了双水相萃取废液中聚乙二醇的回收利用,旨在降低生产成本,减少COD排放,推动双水相萃取技术的工业应用进程。以聚乙二醇-硫酸铵[PEG-（NH4）2SO4]组成的双水相体系废液为原料,采用脱色、浓缩、洗涤除去杂质的工艺技术路线,确定了从双水相废液中回收成相聚合物PEG的最佳工艺（：1）利用H2O2法脱色,最佳脱色条件：H2O2浓度为6%,脱色温度为60℃,脱色时间为4 h,体系pH值为9.0,脱色率达到85%以上（;2）采取盐析法浓缩,最佳电解质种类为Na2SO4,最佳加入量为每10 mL废液3.0 g Na2SO4,此时PEG浓缩比为3.45,PEG损失率为0.31%。按照药用级PEG产品质量标准,对干燥后的回收物进行质量检测。结果表明：回收的PEG产品外观呈浅黄色蜡状,电导率为10.8μs/cm,凝固点为37～40℃,pH值（5%水溶液）为6.33,较纯品PEG无明显差异。     

黄芩甙在EOPO/盐双水相系统中的分配系数测定及关联

The partition coefficients of baicalin were measured in ethylene oxide and propylene oxide(EOPO)/salt aqueous two-phase systems at 298.15K,It was found that most of baicalin partitioned into EOPO-rich phase.The partition coefficients of baicalin varied from 10 to 120.The effect of various factors,including tie-line lngth,salt composition,molecular weight of EOPO,and solution pH,on the partition behavior was investigated on EOPO/salt systems.Furthermore the partition coefficients of baicalin were correlated using the modified Diamond-Hsu model.Good agreement with experimental data is obtained.The average relative deviations are less than 5.0%.     

聚乙二醇-硫酸铵双水相萃取结晶紫的研究

利用分光光度法研究了结晶紫在聚乙二醇-硫酸铵双水相体系中的萃取行为,探讨了质量配比(mPEG/m(NH4)2SO4)、温度、结晶紫浓度对结晶紫的分配系数(cup/clow)及萃取率的影响。结果表明,在一定的温度和结晶紫浓度下,随着质量配比的减小,结晶紫的分配系数增大,萃取率略有降低;在一定的质量配比和结晶紫浓度下,随着温度的升高,分配系数显著增大,萃取率基本保持不变;在一定的质量配比和温度下,随着结晶紫浓度的增大,分配系数显著减小,萃取率基本保持不变;在mPEG/m(NH4)2SO4为1.25∶1、结晶紫浓度为6.536×10-5 mol.L-1、温度为50℃的条件下,萃取率高达99.81%。     

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.     

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.

     

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.     

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...     

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.     

丙烯酰胺在聚乙二醇水溶液中可逆加成-断裂链转移聚合

结合双水相聚合和可逆加成-断裂链转移(RAFT)聚合,提出在聚乙二醇(PEG)水溶液中进行丙烯酰胺(AM)的RAFT双水相聚合,考察反应条件对聚合反应速率和产物分子量及分布的影响。结果表明:高引发剂浓度、单体浓度和聚合温度可以提高初始聚合速率和最终转化率,PEG和RAFT试剂浓度的增加会导致聚合速率减慢和最终转化率降低;峰值聚合速率随引发剂浓度、单体浓度和聚合温度的增加而增大,同时峰值聚合速率对应的时间提前;RAFT试剂浓度增加会推迟峰值聚合速率对应的时间,但可制得分子量分布较窄的产物;PEG浓度的增加会导致产物的分子量分布变宽。     

双水相亲和分离人体血清蛋白质的研究

本文采用七种活性染料为亲和配体,在双水相系统中分离人血清白蛋白、α球蛋白和β-球蛋白。实验结果表明这七种染料配体对白蛋白和β-球蛋白具有一定的亲和作用,对α-球蛋白的亲和力不显著。其中,配体活性金黄K-MG对所研究的蛋白质具有良好的亲和作用和选择性,是一种具有较高应用价值的染料配体。 本文还探讨了pH值、盐及温度等因素对三种蛋白质分配效果的影响。     

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%。     

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.     

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.     

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.