A simple acid digestion using HCl–HNO3−NH4HF2 for rapid SF-ICP-MS determination of 237Np and Pu isotopes in steel and concrete samples

A rapid method was developed to analyze 237Np and Pu isotopes in steel and concrete samples using HCl–HNO3–NH4HF2 digestion, CaF2/LaF3 co-precipitation, AG MP-1 M resin column separation and SF-ICP-MS measurement. Compared to acid digestion using HCl–HNO3–HF, the whole procedure not only avoids the use of toxic HF, but can be completed within 1 day. The decontamination factor of U was estimated to be 1.1 × 106. The limits of detection of 237Np, 239Pu, and 240Pu were 0.25, 0.16, and 0.14 fg g−1, respectively, allowing method users to sufficiently detect low level Pu and Np in steel and concrete samples.