TY - JOUR
T1 - Affinity partitioning of metal ions in aqueous polyethylene glycol/salt two-phase systems with PEG-modified chelators
AU - Aguiñaga-Díaz, P. A.
AU - Guzmán, R. Z.
N1 - Funding Information:
The authors would like to acknowledge the partial financial support of the Arizona Mining and Mineral Resources Research Institute under USBM Grant G111410.
PY - 1996
Y1 - 1996
N2 - 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 diamme], PEG-TREN-Cm [carboxymethylated-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.
AB - 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 diamme], PEG-TREN-Cm [carboxymethylated-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.
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U2 - 10.1080/01496399608001408
DO - 10.1080/01496399608001408
M3 - Article
AN - SCOPUS:0030153018
SN - 0149-6395
VL - 31
SP - 1483
EP - 1499
JO - Separation Science and Technology
JF - Separation Science and Technology
IS - 10
ER -