Radiolytic Stability of TODGA: Characterization of Degraded Samples under Different Experimental Conditions

A Comparison of theγ-Radiolysis of TODGA and T(EH)DGA Using UHPLC-ESI-MS Analysis

“…3 is representative). This is in general agreement with Galán et al, [23] who found abundant production of the compounds labelled here as I, III, and IV in TODGA samples. Because there were no standards for these radiolysis products, the magnitudes of their signal intensities cannot be directly related to concentrations.…”

“…Galán et al [23] reported the same radiolysis products for dry and acid-contacted TODGA solutions, although their abundances varied. In that work, acidity apparently favored rupture of the ether bond, to generate compound III; that effect was not detected here.…”

“…A product detected here that was not reported previously was compound I, Downloaded by [New York University] at 23:55 14 June 2015 , which result from loss of a single side-chain followed by replacement with a hydrogen atom. However, Galán et al [23] did detect the de-alkylation product for irradiated TODGA. Curiously, the analogous radiolysis products, loss of two side-chains, were not detected in this or the previous work.…”

“…Given the low starting concentration of DGAs (0.05 M), the likely mechanism for radiological degradation would be by reaction of a direct radiolysis product of the diluent, n-dodecane, as postulated by Sugo et al [16] It must be noted that this is in contrast to the results of Galán et al, [23] who reported a protective effect for TODGA solutions pre-equilibrated with 3 M HNO 3 . There does not appear to be any difference in the degradation rates between TODGA and T(EH)DGA.…”

“…However, both Sugo et al [14] and Galán et al [23] identified dioctylamine (DOA) in irradiated TODGA. Sharma et al [15] identified the corresponding amine di(ethylhexyl)amine (D(EH)A), in the T(EH)DGA system.…”