242 Pu as tracer for simultaneous determination of 237 Np and 239,240 Pu in environmental samples
A procedure has been developed using 242Pu as tracer for simultaneous determination of 237Np and 239,240Pu in environmental samples. The validity of the method has been demonstrated by ICPMS and a-spectroscopy for up to 10 gram soil and sediment, seawater up to 200 litres. The paper describes a suitable chemical procedure for Np and Pu including a quantitative pre-concentration of neptunium and plutonium, preparation of Np4+ and Pu4+, Np(NO3)6
2- and Pu(NO3)6
2-. The ratio of 237Np/242Pu (or 237Np/239Pu) before and after the procedure has been determined using 10 g soil (free from Np and Pu) R
after = 1.004±3.3% (S.D n = 20) and 1 litre seawater R
after = 1.019±1.9% (S.D., n = 12). Results from the intercomparison samples IAEA-135, IAEA-381 and from environmental samples are presented.