Rapid method for sequential determination of Pu and Am in soil and sediment samples by sector-field inductively coupled plasma mass spectrometry

Abstract

New method was developed to analyze Pu and Am sequentially for soil and sediment by inductively coupled plasma mass spectrometry (ICPMS). The developed method uses conc. HNO3 to leach Pu and Am, Fe(OH)3 coprecipitation to remove alkali and alkaline metals, extraction chromatographic separation using UTEVA, DGA and TEVA resins to remove interfering elements (IEs) and separate Pu and Am from each other, and sector field-ICPMS to measure Pu and Am. The analysis of four standard reference materials showed that both Pu isotopes and 241Am were accurately determined by this method, as a result of its excellent decontamination ability of IEs. Especially the high decontamination factor of Pu [DF(Pu), 4.2 × 102] in Am fraction and high DF(Am) (7.0 × 103) in Pu fraction sufficiently eliminated the cross interference between 241Pu and 241Am in ICPMS measurement. In addition, stable and high chemical recoveries were achieved for Pu (71–91%) and Am (70–88%). The low LODs of Pu isotopes, short analytical time (14 h) and high DFs of IEs allows this method to sequentially analyze Pu and Am, for both global fallout and nuclear accident sourced samples.