Polyethylene glycol (PEG)-aqueous biphasic systems (ABS) and PEG-grafted aqueous biphasic extraction chromatographic (ABEC) resins have been shown to remove inorganic species from environmental and nuclear wastes. The partitioning behavior of several iodide species (iodide, iodine, triiodide, iodate, and 4-iodo-2,6-dimethylphenol (I-DMP)) have been studied for PEG (MW 2000)-salt systems and ABEC resins. Iodide partitioning to PEG-rich phases or onto ABEC resins can be enhanced by derivatization with 2,6-dimethylphenol to form 4-iodo-2,6-dimethylphenol or by addition of I(2) to form triiodide. Conversely, iodide partitioning to the PEG-rich phase or onto ABEC resins is reduced by oxidation of iodide to IO(3)(-). Partitioning studies of iodide, iodate, and iodine in a PEG-ABS are compared to results using ABEC resins.
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http://dx.doi.org/10.1016/j.jchromb.2004.01.051 | DOI Listing |
J Chromatogr A
August 2023
Department of Chemistry and Biochemistry, University of Wisconsin - Milwaukee, Milwaukee, WI 53211, USA. Electronic address:
An aqueous biphasic system (ABS) comprising solutions of ammonium sulfate and polyethylene glycol-2000 (PEG-2000) in which the latter is supported on a porous polymeric substrate (Amberlite XAD-16) has been characterized by examining its performance in the removal of dyes from aqueous solution. Comparison of its behavior to that of a commercial sorbent (ABEC) consisting of a polyethylene glycol covalently bound to a polymer support indicates that the capacity, uptake kinetics, and efficiency of the supported ABS are comparable or superior to that of the ABEC resin. In addition, results obtained at various PEG-2000 concentrations and with PEGs of a range of molecular weights demonstrate that in contrast to ABEC resin, the behavior of a supported ABS can be readily "tuned" to provide the desired dye retention.
View Article and Find Full Text PDFNucl Med Biol
May 2012
Nuclear Medicine, TRIUMF, Vancouver, BC, Canada.
Introduction: The shortage of reactor-produced molybdenum-99 ((99)Mo, t(½)=66 h) has renewed interest in alternative production methods of its daughter isotope, technetium-99m ((99m)Tc, t(½)=6.02 h). While adsorption chromatography serves as a mechanism for selective elution of sodium pertechnetate from technetium generators, this method of purification is not sufficient for many alternative production methods.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
November 2006
Center for Green Manufacturing and Department of Chemistry, The University of Alabama, Tuscaloosa, AL 35487, USA.
Variation in operational temperatures has revealed differences in the partitioning behavior of probe solutes between the phases in aqueous biphasic systems (ABS) and the related aqueous biphasic extraction chromatographic resin (ABEC). This difference has been studied using the hydrophobic anion, 99TcO4-, as a probe and (NH4)2SO4 as the kosmotropic salt. Distribution of the hydrophobic anion 99TcO4- to the PEG-rich phase in a MePEG-5000/(NH4)2SO4 ABS increases with increasing temperature, but decreases are observed in batch uptakes of this anion to ABEC resins from (NH4)2SO4 solutions.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
July 2004
Department of Chemistry and Center for Green Manufacturing, The University of Alabama, Tuscaloosa, AL 35487, USA.
Polyethylene glycol (PEG)-aqueous biphasic systems (ABS) and PEG-grafted aqueous biphasic extraction chromatographic (ABEC) resins have been shown to remove inorganic species from environmental and nuclear wastes. The partitioning behavior of several iodide species (iodide, iodine, triiodide, iodate, and 4-iodo-2,6-dimethylphenol (I-DMP)) have been studied for PEG (MW 2000)-salt systems and ABEC resins. Iodide partitioning to PEG-rich phases or onto ABEC resins can be enhanced by derivatization with 2,6-dimethylphenol to form 4-iodo-2,6-dimethylphenol or by addition of I(2) to form triiodide.
View Article and Find Full Text PDFJ Chromatogr B Biomed Sci Appl
June 1998
Department of Chemistry, The University of Alabama, Tuscaloosa 35487, USA.
Poly(ethylene glycol)-based aqueous biphasic systems (PEG-ABS) can be utilized to separate and recover metal ions in environmental and hydrometallurgical applications. A concurrent study was conducted comparing the partitioning of mercury between aqueous layers in an ABS [Me-PEG-5000/(NH4)2SO4] and partitioning of mercury from aqueous solutions to aqueous biphasic extraction chromatographic (ABEC-5000) resins. In ammonium sulfate solutions, mercury partitions to the salt-rich phase in ABS, but by using halide ion extractants, mercury will partition to the PEG-rich phase after formation of a chloro, bromo or iodo complex.
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