Sequential chemical separations and multiple ion counting ICP-MS for 241 Pu– 241 Am– 237 Np dating of environmental collections on a single aliquot

We have developed a combined sequential chemical separation procedure and multiple ion counting ICP-MS measurement method for isotopic measurements of Am in environmental samples. This, in conjunction with established resin bead TIMS measurements for Pu and Np, allows us to measure long-lived Pu–Np–Am nuclides in environmental samples on a single solution aliquot. This single aliquot method reduces time lines and maximizes sample utility for the measurements, improving sensitivity, precision, and accuracy over prior methods. We have evaluated this new method with environmental reference materials and have obtained accurate results on samples with > 3E6 atoms 241 Am.