Application of AG 1-X8 and TEVA resins for determining of 239Pu and 240Pu in seawater samples by ICP-MS

Abstract

We established procedure for determining ²³⁹Pu and ²⁴⁰Pu radioactive isotopes in seawater samples by inductively coupled plasma mass spectrometry (ICP-MS) method. After suitable pre-treatment of the samples, the plutonium nuclides in solution were co-precipitated with MnO₂ and separated from the large amount of Mn by performing a second precipitation of Fe(OH)₃ at pH ≈ 6. After that, plutonium separated from interfering elements by using of AG 1-X8 and TEVA resins. Plutonium isotopes were eluted with HCl 8 M-NH₄I 7.5% from AG 1-X8 resin, converted into nitrate form and separated from TEVA resin with HCl 0.05 M + HF 0.01 M. The final solution was measured by ICP-MS (Perkin Elmer 300X), with a mean chemical yield of 80% determined with ²⁴²Pu as a tracer when analyzing 20 liters seawater sample. The detection limits were estimated to be 50 fg mL^-1 for ²³⁹Pu and ²⁴⁰Pu.

Key words: ICP-MS; ²³⁹Pu and ²⁴⁰Pu; AG 1-X8 and TEVA resins; seawater samples