Authors:S. Heller-Zeisler, M. Donais, and R. Zeisler
Instrumental neutron activation analysis (INAA) has been employed in the investigation of mass balance for mercury species
analysis in the analytical process. A new human hair reference material (IAEA-085) was analyzed for methylmercury using a
solid/liquid extraction procedure, with samples of extracts, residues, and untreated samples being analyzed by INAA. The certified
reference material NIES CRM No. 13, human hair, was analyzed in parallel. From the results obtained through the mass balance
studies, it was found that the extraction procedure was quantitatively complete, and that there was no difference between
the mass balance of Hg and the total Hg in the untreated materials.
Authors:O. Rizo, E. Herrera Peraza, M. Manso Guevara, I. Pellón, M. López Reyes, M. Cabrera, and M. Montero Cabrera
The main results obtained during the characterization of the Triga Mark III reactor at NNRI, Salazar, Mexico, the development
of the nonconventional multimonitor HAV-1, the use of Certified Reference Material (CRM) as multimonitor fork0-factors experimental determination, and to study the reactor power and slowing-down thickness dependencies of the reactor
flux parameters and its influence ink0-INAA are presented. The experience of thek0-INAA group at ISCTN, in the application of this analytical technique for different purposes is resumed.
Authors:A. Di Piero, A. Di Piero, M. A. Bacchi, M. A. Bacchi, E. A. N. Fernandes, and E. A. N. Fernandes
The k0-method in INAA has been used at CENA/USP Brazil for analyzing geological and biological materials. With the acquisition of
a well-type detector, it was realized that the true-coincidence effects, originally corrected by semi-empirical procedures
with the in-house k0-software (Quantu-INAA), would affect the accuracy of results. Thus, new coincidence correction algorithms were developed,
based on a theoretical equation for obtaining the correction factors. Validation of the algorithms was performed by analysis
of plant certified reference materials.
The thermal neutron prompt gamma-ray activation analysis (PGAA) facility, operated by the US Food and Drug Administration and National Institute of Standards and Technology Center for Neutron Research, has been redesigned to lower background radiation levels and improved analytical capabilities. Analysis of 22 element standards and food and botanical certified reference materials revealed significant sensitivity increases and lower limits of detection for H, B, C, N, Na, Al, P, S, Cl, K, Ca, Fe, and Cd. Mass fractions for these elements, as well as Mg, Al, Si, Ti, Mn, Fe, Cu, I, Zn, Sm, and Gd, were determined for 6 dietary supplements.
Authors:E. Shabana, K. Al-Hussan, and Q. Al-Jaseem
A relatively simple and rapid radioanalytical method, limited to milk, is adapted for investigating soil, biological and water samples for90Sr. The method is based on a selective separation and successive counting of equilibrium quantities of its daughter 90Y, which can be extracted by tributyl phosphate from nitrate medium and stripped by conc. ammonia solution. 90Y is separated from possible iron and measured by Cerenkov counting. The procedure is thoroughly tested with certified reference materials and used lately for determining90Sr in some environmental samples in the Riyadh region. The results obtained are given and discussed.
Authors:A. Kimura, Y. Toh, M. Oshima, Y. Hatsukawa, and J. Goto
Recycled steel products demands a new technique for determining tramp elements in steel. In this paper, As and Sb in iron
certified reference materials were determined by neutron activation analysis with the multiple gamma-ray detection method.
The determined values are in good agreement with certified and reference values. The lower determination limits (LDL) for
As and Sb in high purity iron are 0.012 and 0.0025 ppm, respectively. As the demanded LDL for As and Sb is 0.1 ppm, the method
described in this work is suitable for determining As and Sb in recycled steel.
Authors:M. Bacchi, L. Santos, E. De Nadai Fernandes, P. Bode, F. Tagliaferro, and E. França
The effectiveness of a Compton suppression system (CSS) for instrumental neutron activation analysis of plant materials was
evaluated. Suppression factors were measured with 137Cs sources. Five certified reference materials were analyzed and the detection limits calculated from both suppressed and
unsuppressed spectra were compared. The CSS demonstrated to be useful for lowering the detection limits of ten out of sixteen
elements tested, showing a maximum improvement factor of 3.9. The system performance was strongly influenced by the sample
composition and also by the measurement conditions, indicating the importance of testing each individual sample type and analytical
A new method is presented for the determination of Au and Pt in biological materials based on neutron activation analysis with radiochemical separation of gold. Separation of gold by electrolytic deposition on a niobium cathode ascertains the highest radiochemical purity without any interference from calcium or other major elements. With199Au as indicator for platinum the gold content of the sample not only strongly affects the limit of detection, but also causes interference by double neutron capture. Replicate analyses of BCR Certified Reference Materials No. 184, 185 and 186 were carried out.
Mn-nodule is one of the most important deep sea mineral resources to be explored and exploited in the next century. Analytical quality control based on this kind of Certified Reference Materials (CRMs) is therefore necessay. In the present work, nearly 30 elements in two Chinese Mn nodule Reference Materials (RMs), GSPN-2 and GSPN-3, were determined using extendedK0-relative comparison NAA technique, developed in our laboratory. The unique features of this work include; (1) high accuracy obtained by the interal validation function of our technique; (2) extensive determinable elements obtained by the hybrid nature of our software and (3) neutron flux self-shielding corrections.
A fast pneumatic transfer facility was installed in Nuclear Engineering Teaching Laboratory (NETL) of the University of Texas
at Austin for the purpose of cyclic thermal and epithermal neutron activation analysis. In this study efforts were focused
on the evaluation of cyclic epithermal neutron activation analysis (CENAA). Various NIST and CANMET certified materials were
analyzed by the system. Experiment results showed 110Ag with its 25 s half-life as one of the isotopes favored by the system. Thus, the system was put into practical application
in identifying silver in metallic ores. Comparison of sliver concentrations as determined by CENAA in CANMET certified reference
materials gave very good results.