Comparison of a radiation counting method and ICP-MS for the determination of 99Tc in environmental samples

Results of 99Tc measurements between radiation and non-radiation counting methods were compared using four radiation sources for which 99Tc has been previously determined with a gas-flow proportional counter or a GM counter. Each 99Tc source consisted of a stainless steel planchet bound by mylar films. Seaweeds collected from the Irish Sea were analyzed and 99Tc was electroplated on the planchet. The 99Tc in each sample was separated and measured again by inductively coupled plasma mass spectrometry (ICP-MS). Tc was continuously removed from each sample with 2M HNO3 and 2M NaOH. After the solution containing Tc was adjusted to 0.1M HNO3, Tc was extracted on a novel extraction chromatographic resin to separate it from Ru. The total recoveries for Tc on the planchet samples were almost the same with an average of 91%. The results of 99Tc measurements by both radiation and non-radiation counting methods agreed well with each other. (author)