Precision of neutron activation analysis for environmental biological materials

Between 1973 and 1974 a special committee "Research on the application of neutron activation analysis to the environmental samples" had been organized at the Research Reactor Institute, Kyoto University. Eleven research groups composed mainly of the committee members cooperated in the intercomparison programme of the reactor neutron activation analysis of NBS standard reference material, 1571 Orchard Leaves and 1577 Bovine Liver. Five different type of reactors were used for the neutron irradiation; i.e. KUR reactor of the Research Reactor Institute, Kyoto University, TRIGA MARK II reactor of the Institute for Atomic Energy, Rikkyo University, and JRR-2, JRR-3, JRR-4 reactor of Japan Atomic Energy Research Institute. Analyses were performed mainly by instrumental method. Precision of the analysis of 23 elements in Orchard Leaves and 13 elements in Bovine Liver presented by the different research groups was shown in table 4 and 5, respectively. The coefficient of variation for these elements was from several to 30 percent. Averages given to these elements agreed well with the NBS certified or reference values. Thus, from the practical point of view for the routine multi element analysis of environmental samples, the validity of the instrumental neutron activation technique for this purpose has been proved.