title: An improved extraction chromatographic resin for the separation of uranium from acidic nitrate media.
abstract: The preparation and characterization of a new extraction chromatographic resin exhibiting extraordinarily strong retention of hexavalent uranyl ion over a wide range of nitric acid concentrations and very high selectivity for U(VI) over Fe(III) and numerous other cations is described. This new material (designated U/TEVA-2) comprises a novel liquid stationary phase consisting of an equimolar mixture of diamyl amylphosphonate (DA[AP]) and Cyanex 923((R)) (a commercially available trialkyl-phosphine oxide, TRPO) sorbed on silanized silica or Amberchrom CG-71. Cyanex 923 is shown to be preferable to a related TRPO, Cyanex 925((R)), due to its lower viscosity and higher selectivity for U(VI) over Fe(III). The retention of uranyl nitrate by the U/TEVA-2 resin, as measured by the k' values (number of free column values to peak maximum) is >5000 from approximately 0.1 to 8 M HNO(3). The ability of the new resin to strongly and selectively retain U(VI) from such a wide range of acid concentrations, along with its favorable physical properties, make it a good candidate for application in the separation and preconcentration of U(VI) from complex environmental, biological, and nuclear waste samples for subsequent determination.
authors.affiliation: Chemistry Division, Argonne National Laboratory, Argonne, IL 60439, USA.
authors.forename: M L
authors.initials: ML
authors.lastname: Dietz
authors.forename: E P
authors.initials: EP
authors.lastname: Horwitz
authors.forename: L R
authors.initials: LR
authors.lastname: Sajdak
authors.forename: R
authors.initials: R
authors.lastname: Chiarizia