On the role of neutron activation analysis in the certification of a new reference material for trace-element studies,mixed human diet,H-9

A new biological reference material, which is representative of diets consumed in Finland, has been characterized by means of an intercomparison exercise conducted by the IAEA in the second half of 1985 and in 1986. Results for 35 elements received from 79 participants in 33 countries have been evaluated. A certificate of analysis has been issued with provisional certified values for 22 elements and information values for 2 elements. Neutron activation analysis (NAA) provided approximately one third of all the results reported. Instrumental NAA was used approximately 5 times as frequently as radiochemical NAA. Overall, NAA played an important role in providing useful data for the following 20 elements: Al, As, Br, Cl, Co, Cr, Cs, F, Fe, Hg, I, K, Mn, Mo, Na, Rb, Sb, Sc, Se and Zn. In comparison with the main competing non-nuclear method (usually atomic absorption spectrometry), NAA showed a larger dispersion of results for Cd, Cu, K, and Mg, and a smaller degree of dispersion for Co, Cr, Hg, and Se.