Sample preparation method for analysis of swipe samples by inductively coupled plasma mass spectrometry

Abstract

International nuclear safeguards have been applied for over 30 years to control nuclear activities. Following the recon of undeclared nuclear activities in Iraq in 1991, strengthening of the safeguards system became necessary (1995). From 1996 the detection of undeclared nuclear activities using sensitive and precise analysis of swipe samples became one of the most important parts of IAEA inspections. The aim of this study was the development of a fast and easy sample preparation and analysis method for the bulk uranium and plutonium analysis of swipe samples. For the sample preparation low power microwave-assisted digestion followed by extraction chromatography using TRU^® resin was applied. The concentration of analytes of interest and their isotopic composition were determined by inductively coupled plasma sector field mass spectrometry (ICP-SFMS). The analytical performance of the method is in good agreement with the requirements (accuracy, precision, repeatability) of the International Atomic Energy Agency–Network for Analytical Laboratories (IAEA–NWAL) and can be applied for routine analysis. The low detection limits achieved enable the determination of the isotope ratios and isotope concentrations of U and Pu (²³⁴U, ²³⁵U, ²³⁶U, ²³⁸U and ²³⁹Pu, ²⁴⁰Pu, ²⁴¹Pu) present in ultratrace concentration levels in swipe samples. The method was tested with real swipe samples collected at Hungarian radioactive source producing facilities.