Aqueous two-phase partitioning of cephalosporin antibiotics: effect of solute chemical nature

Extraction and separation of anthocyanins from Kushui rose by ethanol-(NH4)2SO4 aqueous two-phase system

Simultaneous extraction of anthocyanins and removal of sugars from Kushui rose was performed using an ethanol-ammonium sulphate aqueous two-phase system (ATPS). The effects of different parameters, such as type of salt, concentrations of salt and ethanol, temperature and pH on the partition coefficient and recovery of anthocyanins in the top system and sugars in the bottom system were studied. Furthermore, an experimental design of a three-level three-factor Box-Behnken design response surface methodology (RSM) was used to obtain optimal extraction conditions. The maximum partition coefficient (5.64) and recovery (78%) of anthocyanins in the top system within the investigated range were obtained at 22% (w/w) concentration of ammonium sulphate, 25% (w/w) concentration of ethanol, pH 5 and 33.5 °C. During the discussion of the main factors, the maximum recovery of sugars reached 70.09%. The HPLC profile of anthocyanins obtained from the ATPS top phase was similar to that of anthocyanins extracted by ethanol, which indicated that the ethanol-ammonium sulphate ATPS was suitable for the extraction of anthocyanins. On the basis of the anthocyanin stability experiment, anthocyanins extracted from Kushui rose should be stored at low pH and temperature.

Aqueous Two-Phase Systems and Microfluidics for Microscale Assays and Analytical Measurements

Phase separation is a common occurrence in nature. Synthetic and natural polymers, salts, ionic liquids, surfactants, and biomacromolecules phase separate in water, resulting in an aqueous two-phase system (ATPS). This review discusses the properties, handling, and uses of ATPSs. These systems have been used for protein, nucleic acid, virus, and cell purification and have in recent years found new uses for small organics, polysaccharides, extracellular vesicles, and biopharmaceuticals. Analytical biochemistry applications such as quantifying protein-protein binding, probing for conformational changes, or monitoring enzyme activity have been performed with ATPSs. Not only are ATPSs biocompatible, they also retain their properties at the microscale, enabling miniaturization experiments such as droplet microfluidics, bacterial quorum sensing, multiplexed and point-of-care immunoassays, and cell patterning. ATPSs include coacervates and may find wider interest in the context of intracellular phase separation and origin of life. Recent advances in fundamental understanding and in commercial application are also considered.

Aqueous two-phase systems as a tool for bioseparation – emphasis on organic acids

Aqueous two-phase systems (ATPS) are universally recognized as an excellent alternative to the conventional separation techniques in the biotechnology, because of their undoubted advantages such as mild and biocompatible conditions, high water content, low interfacial tension, ease of process integration and scale up, etc. The formation of ATPS is due to the incompatibility of two polymers in a common solution. Other types of ATPS are formed by polymer/salt, ionic and/or non-ionic surfactants, inorganic salt/short-chain alcohols, and based on room temperature ionic liquids. ATPS are successfully used (even in large scale) for cells, enzyme and protein separation, while their application for recovery of small molecules such as organic acids, antibiotics, alcohols is more complicated as they are usually hydrophilic and tend to distribute evenly between the phases. The purpose of this paper is to overview and summarize the efforts made for the application of different types of ATPS for the separation of organic acids.

Improving the extraction and purification of immunoglobulin G by the use of ionic liquids as adjuvants in aqueous biphasic systems

Immunoglobulins G (IgG) could become widespread biopharmaceuticals if cost-efficient processes for their extraction and purification are available. In this work, aqueous biphasic systems (ABS) composed of polyethylene glycols and a buffered salt, and with ionic liquids (ILs) as adjuvants, have been studied as alternative extraction and purification platforms of IgG from a rabbit serum source. Eleven ILs were investigated to provide insights on the chemical features which maximize the IgG partitioning. It is shown that in polymer-salt systems pure IgG preferentially partitions to the polymer-rich phase; yet, the complete extraction was never attained. Remarkably, after the addition of 5wt% of adequate ILs to polymer-salt ABS, the complete extraction of pure IgG in a single-step was accomplished. The best systems and conditions were then applied to the extraction and purification of IgG directly from rabbit serum samples. The complete extraction of IgG in a single-step was maintained while its purity in the polymer-rich phase was enhanced by ca. 37% as compared to the IL-free ABS. The antibody stability was also evaluated revealing that appropriate ILs are able to maintain the IgG stability and can be used as phase-forming components of ABS when envisaging the purification of high-cost biopharmaceuticals.

Partitioning of Cephalexin in Ionic Liquid Aqueous Two-Phase System Composed of 1-Butyl-3-Methylimidazolium Tetrafluoroborate andZnSO4

Ionic liquid aqueous two-phase system (ILATPS) was applied in the extraction and separation of hydrosoluble antibiotics. The partitioning behavior of cephalexin (CEX) in 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF4)-ZnSO4aqueous two-phase system was studied by the partitioning parameter of the extraction efficiency. The effect of the volume of [Bmim]BF4, the concentration of ZnSO4, temperature, pH, and the volume of ZnSO4solution was discussed concretely. When the volume of [Bmim]BF4was 2 mL and the concentration of ZnSO4was 35%, the extraction efficiency of CEX could reach 92.64% with pH unadjusted. The effect of the volume of [Bmim]BF4on the extraction efficiency was higher than that of the concentration of ZnSO4. The temperature influenced not only the formation of aqueous two-phase system but also the extraction efficiency of CEX. The target was found to be preferentially extracted to the [Bmim]BF4-rich phase at the pH below 4.3. The partition of CEX to the top phase was enhanced by increasing the volume of [Bmim]BF4, the concentration of ZnSO4, and temperature; however, the partition of CEX to the top phase increased by decreasing the pH.

Separation of clavulanic acid from fermented broth of amino acids by an aqueous two-phase system and ion-exchange adsorption

The clavulanic acid is a substance which inhibits the β-lactamases used with penicillins for therapeutic treatment. After the fermentation, by-products of low molecular weight such as amino acids lysine, histidine, proline and tyrosine are present in the fermented broth. To remove these impurities the techniques of extraction by an aqueous two-phase system of 17% polyethylene glycol molecular weight 600 and 15% potassium phosphate were used for a partial purification. A subsequent ion-exchange adsorption was used for the recuperation of the clavulanic acid of the top phase and purification getting a concentration factor of 2 and purification of 100% in relation to the amino acids lysine, histidine, proline and tyrosine.

Extraction and mechanism investigation of trace roxithromycin in real water samples by use of ionic liquid-salt aqueous two-phase system

The ionic liquid, as a green solvent, has several advantages over the organic solvents in traditional liquid-liquid extraction. Aqueous two-phase system (ATPS) consisting of a hydrophilic ionic liquid (1-butyl-3-methylimidazolium tetrafluoraborate, [Bmim]BF(4)) and Na(2)CO(3), which is a novel, simple, non-toxic and effective sample pretreatment technique coupled with molecular fluorescence spectrophotometry, was developed for the simultaneous separation, enrichment and rapid analysis of roxithromycin. The extraction yield of roxithromycin in [Bmim]BF(4)-Na(2)CO(3) aqueous two-phase system is influenced by the types of salts, concentrations of Na(2)CO(3) and [Bmim]BF(4), as well as the extracting temperature. Under the optimum conditions, the average extraction efficiency is up to 90.7%. The mechanism of ionic liquid-salt ATPS formation was discussed by hydration theory, and the extraction mechanism of the [Bmim]BF(4)-salt ATPS was investigated by FT-IR spectroscopy and UV-vis spectroscopy. The results demonstrate that no chemical (bonding) interactions are observed between ionic liquid and roxithromycin, while the nature properties of the roxithromycin are not altered. This method was practical when applied to the analysis of roxithromycin in real water samples with the detection limit of 0.03 microg mL(-1), relative standard deviation (RSD) of 1.9% (n=13), and linear ranges of 1.00-20.00 microg mL(-1). The proposed extraction technique will be promising in the separation of other small biomolecules.

Recovery and Purification of Nicotine from Waste Tobacco by Aqueous Two-Phase System/Reverse Extraction

A two-step process has been developed for the purification of nicotine from waste tobacco using an aqueous two-phase system and solvent reverse extraction. The partitioning behavior of nicotine was investigated in an isopropyl alcohol/ (NH4)2SO4 aqueous two-phase system. The effects of the addition of salt, pH and temperature on the partitioning behavior of nicotine were studied. The recovery rate of nicotine was 96.1% with a purity of above 99% when optimal conditions were used [(NH4)2SO4 25%, pH 9, temperature 35°C, isopropyl alcohol 5 mL].

Separation and purification of Aloe polysaccharides by a combination of membrane ultrafiltration and aqueous two-phase extraction

A two-step process was developed for the purification of polysaccharides from the pulp of Aloe varavia using aqueous two-phase system (ATPS) extraction and a novel copolymer ultrafiltration membrane. The first step was ATPS under optimal separations conditions using a total composition of 18% PEG2000, 25% ammonium sulfate, pH 3.0, and 0.3 M NaCl. To form the copolymer membrane, poly(acrylonitrile-acrylamide-styrene) was prepared by solution polycondensation using azoisobutyronitrile as initiator. Then, membranes were formed from the dissolved copolymer by the phase inversion method. Copolymer structure was investigated by infrared spectrum and thermogravimetric analysis (TGA). The copolymer membrane surface and cross section were observed by scanning electron microscopy. The water flux of this membrane was 26.33 mL/(cm(2) h), and retention was 96% for bovine serum albumin and 34% for dextran T40000. The separation and purification of aloe polysaccharide were carried using this copolymer membrane following ATPS. The TGA of aloe polysaccharide demonstrated a high purity of the polysaccharide. By gas chromatographic analysis, it was shown that mannose is the main monosaccharide in the aloe polysaccharide, and only a few glucose residues are present.