Review of neutron activation analysis in the standardization and study of reference materials, including its application to radionuclide reference materials

摘要: Neutron activation analysis (NAA) plays a very important role in the certification of reference materials (RMs) and their characterization, including homogeneity testing. The features method are briefly reviewed, particularly aspects relating to its completely independent nuclear basis, virtual freedom from blank problems, capacity for self-verification. This last aspect, arising essentially isotopic character NAA, can be exploited by using different reactions induced nuclides, possibility employing two modes, one instrumental (nondestructive), other radiochemical (destructive). enables derivation analytical information unique NAA self-validation. application quantify natural or man-made radionuclides such as uranium, thorium, 237Np, 129I 230Th is discussed, advantages over conventional radiometric methods, usefulness providing data nuclides where confirmatory analyses impossible, only recently becoming available through newer “atom counting” techniques. Certain additional, prospective uses study RMs potential mentioned, transmutation reactions, creation endogenously radiolabelled matrices production (such dissolution leaching tests, use incorporated radiotracers chemical recovery correction), molecular speciation.