| Popis: |
A procedure has been developed for the determination of 99 Tc in vegetation, by use of 95m Tc as an internal tracer. The samples are wet-ashed, without significant loss of Tc. The Tc is separated from most other radionuclides by precipitation with calcium carbonate, and is purified by anion-exchange chromatography and electro-deposition. The radiochemical yield of Tc is determined by Ge(Li) gamma-ray spectrometry of the 204-keV photon peak of the 95m Tc internal tracer, and the 99 Tc activity is determined by counting its 0.292-MeV beta-particles with a scintillation counter. The detection limit for 99 Tc in a sample weighing about 10 g is 0.1 pCi for a 3000-min count. |
