The influence of seasonal changes in the concentration of trace elements in liver tissue of various wild animals determined by instrumental neutron activation analysis

Levels of some of the most essential minerals in liver tissue of wild animals living in game reserves in South Africa were studied by instrumental thermal neutron activation analysis and a Ge(Li) detector. For convenience of counting in the determination of Se, the samples and only the liver reference standards, all sealed in polyethylene containers, were irradiated separately and in fixed sequence for ninety seconds. The relative values of the integrated neutron fluxes were determined for some samples and standards by using gold monitor samples. Irradiations were done in the pneumatic facility of SAFARI-1 at Pelindaba. The thermal neutron flux is about 3x1013n cm-2 sec-1. For the determination of Al, Br, Ca, Cl, Cu, K, Mg, Na and V in the liver samples, samples and reference standards were again irradiated separately for ten minutes. For the determination of Au, Ce, Co, Cr, Fe, Hg, La, Rb, Sb, Sc and Zn in the liver samples, samples and reference standards, all sealed in quartz ampoules, were irradiated for sixty hours in the poolside facility at a flux of 4x1013 n cm-2 sec-1. In addition, some of the most important trace elements were determined by atomic absorption spectrometry. The distribution of the content of the various elements was followed for about two years and attempts have been made to explain the influence of seasonal fluctuations of the micronutrients determined. (T.G.)