A pseudo-cyclic instrumental neutron activation analysis method in conjunction with anti-coincidence gamma-ray spectrometry
(PC-INAA-AC) has been developed for the determination of ppb levels of Se. The method consists of repetitions of the irradiation-decay-counting
cycles of a sample using the rapid transfer cyclic system at the Dalhousie University SLOWPOKE-2 reactor facility. The 162-keV
γ-ray of 77mSe (t1/2 = 17.4 s) has been found to be highly selective. The precision and detection limits are significantly improved and the total
experimental time drastically reduced by this method. Detection limits are between 2 and 9 ng. The accuracy of the method
has been evaluated by analyzing a number of nutritional reference materials. The PC-INAA-AC method has been applied for the
routine determination of Se to the composites of 135 food samples with values ranging from as low as 1 ng g−1 for tea to 1,045 ng g−1 for organ meats on fresh weight basis.