Metal Ion Separations in Polyethylene Glycol-Based Aqueous Biphasic Systems

Phase diagrams of aqueous two-phase systems formed by polyethylene glycol+ammonium sulfate+water: equilibrium data and thermodynamic modeling

“…Particularly, ATPS formed by PEG + (NH 4 ) 2 SO 4 + H 2 O has been studied for a long time [14,15]. These ATPS have been used in the extraction of various analytes, such as ionic species [16,17], small molecules [18], and also in the partition proteins [19]. These ATPS in general, have physicochemical properties which vary considerably with molecular weight PEG.…”

Application of polyethylene glycol-based aqueous biphasic reactive extraction to the catalytic oxidation of cyclic olefins

“…1) are connected by the tie line AB, such that any system composition along that tie line will phase separate into an upper phase of composition A and a lower phase of composition B. Since solute preference between the two phases can be affected by varying phase divergence described by the tie-line length (TLL), the differences in phase preference between precursor and product in a given reaction can be adjusted by controlling the ABS system composition [3,15]. In a typical reaction for this study (Fig.…”

“…More recently, we have investigated the partitioning and separation of organic hydrocarbon species [10][11][12][13] and metal ions [14][15][16][17] in ABS to obviate the need for volatile organic solvents (VOCs) in liquid/liquid partitioning. Other researchers have now started to examine low molecular weight liquid polyethylene glycol (PEG) as new solvent systems for reactive chemistry, e.g., for osmium tetroxide catalyzed asymmetric dihydroxylation [18], polyoxometallate catalyzed aerobic oxidation [19], hydrolysis reactions [20,21], and as alternative phase transfer catalysts (PTC) [22].…”

Effects of speciation on partitioning of iodine in aqueous biphasic systems and onto ABEC® resins

“…The iodide tracer as Na 125 I and the technetium tracer as NH 4 99 TcO 4 in 0.1 M NH 4 OH were obtained from Amersham Life Science, Inc. (Arlington Heights, IL, USA) and used as received. Iodide as Na 129 I was obtained from Isotope Products Laboratories (Burbank, CA, USA).…”

“…Aqueous biphasic systems (ABS) have been used as a gentle liquid/liquid separation methodology for large and small biomolecules [1], however, there is an increasing number of applications of ABS to liquid/liquid separation of inorganic ions and organic molecules [2][3][4][5][6][7]. Earlier results utilizing both polyethylene glycol (PEG)-ABS and the related aqueous biphasic chromatographic resin (ABEC) to separate and recover iodide from environmental and nuclear wastes [3] for either remediation or analysis, prompted this study to analyze the effects of iodine speciation on the liquid/liquid distribution values and compare them to ABEC batch uptakes.…”