Interfacing capillary electrophoresis with inductively coupled plasma mass spectrometry for redox speciation of plutonium

A robust and efficient interface between a capillary electrophoresis (CE) and an ICP-MS for actinide speciation studies was developed. This interface was made of two stainless steel T-shape pieces connected to the ICPMS through a PFA-50 nebulizer. Fast separations (typically in less that 15 min) were obtained. The performances of the technique in terms of chemical separations carried out by the capillary electrophoresis and in terms of detection limits were investigated. Concerning the detection limit of the CE-ICP-MS system for plutonium, it was determined as 5 x 10(-10) mol L-1 or 9 x 10-(18) mol under our injection conditions. The coupling enables to separate at least three (111, V and VI) of the four plutonium oxidation states which can exist in aqueous solutions and to monitor oxidation and reduction processes.