Separation of Plutonium and Neptunium Species by Capillary Electrophoresis−Inductively Coupled Plasma-Mass Spectrometry and Application to Natural Groundwater Samples

Abstract

Capillary electrophoresis (CE) was coupled to ICPMS in order to combine the good performance of this separation technique with the high sensitivity of the ICPMS for the analysis of plutonium and neptunium oxidation states. The combination of a fused-silica capillary with a MicroMist AR 30-I-FM02 nebulizer and a Cinnabar small-volume cyclonic spray chamber yielded the best separation results. With this setup, it was possible to separate a model element mixture containing neptunium (NpO2(+)), uranium (UO2(2+)), lanthanum (La3+), and thorium (Th4+) in 1 M acetic acid. The same conditions were also suitable for the separation of various oxidation states of plutonium and neptunium in different aqueous samples. All separations were obtained within less than 15 min. A detection limit of 50 ppb identical with 2 x 10(-7) M (3-fold standard deviation of a blank) was achieved. To prove the negligible disturbance of the plutonium and neptunium redox equilibria during the CE separations, plutonium and neptunium speciation by CE-ICPMS in acidic solutions was compared with the results of UV/visible absorption spectroscopy and was found to be in good agreement. The CE-ICPMS system was also applied to study the reduction of Pu(VI) in a humic acid-containing groundwater at different pH values.

Detection and quantification of Pu(III, IV, V, and VI) using a 1.0-meter liquid core waveguide

“…This CE-ICP-MS system allows for the separation of actinides along the CE column and detection with the ICP-MS. The limits of detection for this system were reported as 0.2 µM for a single oxidation state of an actinide [9]. While providing a limit of detection superior to UV-VIS spectroscopy, this method requires the use of expensive ICP-MS and CE systems.…”

“…This method uses a tunable laser system to scan through the wavelengths of interest and the signal is detected using a piezoelectric transducer [8] [9]. This CE-ICP-MS system allows for the separation of actinides along the CE column and detection with the ICP-MS.…”

Défis actuels et à venir en matière d'analyse de traces et d'ultra-traces

“…Cette méthode est élégante et sensible, mais elle reste tributaire du caractère fluorescent de certains éléments (uranium, terres rares, curium), elle n'est donc pas universellement applicable. Elle est concurrencée pour la spéciation par la spectrométrie de masse, de manière directe, dans une source de type électrospray [29], séparation préalable (HPLC) [30] ou élec-trophorèse capillaire [31,32] puis transfert dans la source d'un ICPMS. En ce qui concerne les méthodes mettant en oeuvre une introduction directe de l'échantillon dans la source d'un spectromètre de masse, il est possible de calculer la stabilité des espèces produites dans la source et de comparer avec les spectres de masse enregistrés.…”

Rapid Separation and Quantification of Iron in Uranium Nuclear Matrix by Capillary Zone Electrophoresis (CZE)

“…These include employing non-aqueous media [16,17], use of partial or complete complexation techniques [18,19], using CE in conjunction with ICP-MS [20][21][22] and use of quantitative microchip CE [23]. Despite the increased applications to inorganic materials, the applica-tion of CE in nuclear industry has been somewhat limited [24,25].…”