Comparison of the role of photon and neutron activation analyses for elemental characterization of geological, biological and environmental materials

The potential of photon activation analysis (PAA) for multielement trace analysis can hardly compare with that of neutron activation analysis (NAA). However, PAA appears superior over NAA for the determination of a number of elements, namely C, N, O, F, Mg, Si, Ca, Ti, Ni, Sr, Y, Zr, Nb, Sn, Tl and Pb in geological, environmental and biological materials. Most of these and other elements can be determined using nondestructive, instrumental PAA (IPAA), especially in geological materials. The possibilities of IPAA for multielement analysis using photoexitation and other photonuclear reactions are reviewed and compared with those of instrumental NAA (INAA), namely for geological materials. The need for and usefulness of radiochemical PAA (RPAA) procedures are also discussed.