Rapid determination of antimony in biological and environmental samples using instrumental neutron activation analysis

A rapid non-destructive activation analysis method has been developed for the determination of antimony. A high resolution low energy Ge detector is used to measure the 61.6 keV γ-ray from 122Sb (T = 4.2 min). Irradiations were performed in a thermal flux of approximately 1.7x1012nxcm-2xs-1. The samples and standards were irradiated for five and fifteen minutes using thermal activation analysis and fifteen minutes using epithermal irradiation. In both instances the decay time and counting time were 2 min and 5 min, respectively. Flux monitors were not used since the variation of the flux is not expected to exceed 1% during eight hours of reactor operation. However, standards were irradiated between every three or four samples and the variation for these was < 12%. Sensitivities and detection limits for biological and environmental samples activated with thermal and epithermal neutrons are listed. The time required for the analysis is about 12 min per sample using thermal activation and 22 minutes using epithermal activation analysis. (T.G.)