Solvent Extraction and Fluorescence Spectroscopic Investigation of the Selective Am(III) Complexation with TS-BTPhen

Kaufholz, Peter, Modolo, Giuseppe, Wilden, Andreas, Sadowski, Fabian, Bosbach, Dirk, Wagner, Christoph, Geist, Andreas, Panak, Petra, Lewis, Frank and Harwood, Laurence (2016) Solvent Extraction and Fluorescence Spectroscopic Investigation of the Selective Am(III) Complexation with TS-BTPhen. Solvent Extraction and Ion Exchange, 34 (2). pp. 126-140. ISSN 0736-6299

Preview

Text Revised Version.pdf - Accepted Version Download (971kB) | Preview

Abstract

An americium(III) selective separation procedure was developed based on the coextraction of trivalent actinides (An(III)) and lanthanides (Ln(III)) by TODGA (N,N,N′,N′-tetraoctyl-diglycolamide), followed by Am(III) selective stripping using the hydrophilic complexing agent TS-BTPhen (3,3′,3ʺ,3ʺ′-[3-(1,10-phenanthroline-2,9-diyl)-1,2,4-triazine-5,5,6,6-tetrayl]tetrabenzenesulfonic acid). Distribution ratios were found at an acidity of 0.65 mol L−1 nitric acid that allowed for the separation of Am(III) from Cm(III) (DCm > 1; DAm < 1), giving a separation factor between curium and americium of SFCm/Am = 3.6 within the stripping step. Furthermore, Am(III) was readily separated from the lanthanides with the lowest selectivity for the Ln(III)/Am(III) separation being lanthanum with a separation factor of SFLa/Am = 20. The influence of the TS-BTPhen concentration on Am(III) distribution ratios was studied, giving a slope (logD vs. log[TS-BTPhen]) of approximately −1 for the stripping of Am(III) with TS-BTPhen from the TODGA-based organic phase. Time-resolved laser fluorescence spectroscopy (TRLFS) measurements of curium(III) were used to analyze the speciation of Cm(III)-TS-BTPhen complexes. Both 1:1 and 1:2 complexes were identified in single-phase experiments. The formation of the 1:1 complex was suppressed in 0.5 mol L−1 nitric acid but it was significantly present in HClO4 at pH 3. Conditional stability constants of the complex species were calculated from the TRLFS experiments.

Actions (login required)

View Item

Downloads