THE ACCURACY OF INSTRUMENTAL NEUTRON-ACTIVATION ANALYSIS OF KILOGRAM-SIZE INHOMOGENEOUS SAMPLES

The feasibility of quantitative instrumental neutron activation analys is (INAA) of samples in the kilogram range without internal standardiz ation has been demonstrated by Overwater et al. (Anal. Chem. 1996, 68, 341). In their studies, however, they demonstrated only the agreement between the ''corrected'' gamma ray spectrum of homogeneous large sam ples and that of small samples of the same material. In this paper, th e k(0) calibration of the IRI facilities for large samples is describe d, and, this time in terms of (trace) element concentrations, some of Overwater's results for homogeneous materials are presented again, as well as results obtained from inhomogeneous materials and subsamples t hereof. It is concluded that large-sample INAA can be as accurate as o rdinary INAA, even when applied to inhomogeneous materials.