Authors:S. Ismail, G. Wiesinger, R. Pavlovec, and F. Grass
Different reference materials of environmental and geological origin, such as NBS 1633a (Coal Fly Ash, CFA), NBS 1645 (River Sediment, RS), GXR-2, and IAEA Soil-5, were investigated by short time activation analysis. The samples were analyzed in 5 replicates each between 100 to 150 mg, at neutron flux of 1.3 E 12 cm–2 s–1, using a high rate — high resolution gamma spectroscopy with a Loss Free Counting (LFC) System to correct the dead time and pile up to 500,000 cps. The results of the measurements indicate that the precision in determination of28Al,46mSc, and52V is between 1 to 6%. Different evaluation programs (i.e. ALCHEM, AKTAN, and ND-PEAK) were used to calculate the peak areas. The results indicate that, at lower counts, the statistical error of peak area calculation becomes more significant. Finally, Mössbauer spectroscopy was used to investigate the main Fe compounds present in some reference materials.
A review is presented on the use of neutron activation analysis (NAA) for the analyses of coal, oil shale, tar sands and petroleum. Fast NAA has been widely used for the determination of oxygen, and to a limited extent, of other elements such as nitrogen and silicon. Reactor NAA followed by instrumental counting, and in specific cases, after radiochemical separations is discussed. Thermal and epithermal neutrons are both used. Limited use of the252Cf source has been made in fuel analysis. A complementary technique to NAA is the photon-activation analysis with linear accelerator. It can determine over thirty elements, many of them not possible to do by NAA. Round-robin analyses of standard coal, fly ash, or oil shale samples indicate nuclear activation methods are comparable in accuracy and precision to X-ray fluorescence or atomic spectrometric methods for most elements.
Authors:Lin Xilei, F. De Corte, L. Moens, A. Simonits, and J. Hoste
USGS BCR-1 and G-2, NBS 1633a Coal Fly-Ash and a 7-element synthetic standard for biological material have been analysed in this work by reactor NAA, using the k0-standardization method. The analyses were performed independently in the analytical laboratories of the Institute for Nuclear Sciences (INW), Gent, and the Central Research Institute for Physics (KFKI), Budapest. This procedure allowed not only a comparison with the specified data or with other published values, but enabled a check of the consistency of our own results obtained in largely different experimental circumstances. As concluded the k0-standardization method combines general versatility (with respect to irradiation and counting conditions) with good accuracy, while keeping the experimental work as simple as possible. Since the k0 method is a computer-oriented technique, a FORTRAN IV program was designed and applied on a VAX 11/780 machine.
Authors:C. Yonezawa, M. Magara, H. Sawahata, M. Hoshi, Y. Ito, and E. Tachikawa
A permanent and stand-alone neutron-induced prompt -ray analysis (PGA) system, usable at both cold and thermal neutron beam guides of JRR-3M has been constructed. The characteristics of the system, including neutron beam and -ray spectrometer were measured. Owing to the absence of fast neutrons and the low -ray background, analytical sensitivities and detection limits better than those in other PGA systems have been achieved. Analytical results of ten elements in Standard Reference Material of Coal Fly Ash agreed well with those obtained by other methods. Isotopic analysis of Ni and its application to accurate and precise determination of Ni by stable isotope dilution method were performed.
Authors:S. Jonah, U. Sadiq, I. Okunade, and I. Funtua
The k0-IAEA program developed for implementation of the single comparator instrumental neutron activation analysis method (k0-INAA) has been used for elemental analysis with NIRR-1 irradiation and counting facilities. The existing experimental protocols
for routine analysis based on the relative method were used to test the capability and reliability of the program for the
analyses of geological and biological samples. The Synthetic Multi-element Standards (SMELS) types I, II and III recommended
by the international k0 user community for the validation of k0-NAA method in NAA laboratories, furthermore, the following standard reference materials: NIST-1633b (Coal Fly Ash) and IAEA-336
(Lichen) were analyzed. Results obtained with the version 3.12 of the k0-IAEA program were found to be in good agreement with the data obtained with the established relative method using WINSPAN-2004
software. Detection limits for elemental analysis of geological and biological samples with NIRR-1 facilities are provided.
In order to assess the source of pollutants and the atmosphere quality in and around a thermal power plant, fugitive dust particulates from seven different locations and ambient air dust from six locations have been analyzed for 32 elements (As, Au, Ba, Br, Ce, Cl, Co, Cr, Cs, Cu, Eu, Fe, Ga, Hg, Hf, K, La, Lu, Mg, Mn, Na, P, Rb, Sb, Sc, Se, Ta, Tb, Te, Th, W and Yb) by employing instrumental neutron activation analysis (INAA). The method involves the irradiation of samples and comparator standards in a thermal neutron flux range of 1012–1013n·cm–2·s–1 in a nuclear reactor for 10 min and 1 day followed by high resolution -spectrometry. Wide differences have been observed in the mean elemental concentrations of Fe, Co, Br, Mn, As, P. Ba and Cu in fugitive and ambient dust particulates coliected from these different locations. Further, a comparison of the elemental contents of the dust particulates from the plant with environmental standards (Urban Particulate Matter, Coal Fly Ash, Vehicle Exhaust and Coal) show significantly lower or comparable amounts of toxic and pollutant elements in the environmental samples.
Authors:A. Garg, N. Chutke, M. Ambulkar, and A. Aggarwal
The process of urbanization and industrialization during las two decades has resulted in increased level of air pollution causing hazards to human health. Instrumental neutron activation analysis (INAA) using short and long term irradiation has been employed for the determination of more than 30 elements in suspended particulate matter (SPM) from six metropolitan cities and three industrial surroundings. A comparison of mean elemental contents in dust particulates from commercial, industrial and residential zones of Delhi, Calcutta, Madras, Cochin, Bombay and Nagpur cities has shown wide variation in toxic pollutant (As, Br, Cr, Cu, Hg and Sb) concentrations. Coastal areas have shown higher concentrations of Na, K, Cl and Br. Highly industrialized Bombay showed highest levels of Br, Cl, Cr, Fe, Mg, P, Rb and Sc. Mean elemental contents in fugitive and ambient dust of a cement factory and thermal power station (both in central India) are widely different. SPM levels in fugitive dust of the two industrial surroundings are higher by an order of magnitude compared to ambient air. Analysis of ambient air dust from a paper mill showed highest concentrations of Hg, Sb and Zn. Elemental data have been compared with those of Urban Particulate Matter (SRM 1648), Coal Fly Ash (SRM 1633a) and Vehicle Exhaust Particulate (NIES No. 8) which were analysed for quality control. An attempt has been made to attribute the elemental contents to possible sources of origin.
In recent years the k0-NAA method has been applied and developed at the 500 kW Dalat research reactor, which includes (1) the establishment of a PC database of k0-NAA-related nuclear parameters, e.g., radionuclide produced, half-lives, k0-factors, Q0, r, Eg, etc; the access to the database is able by a k0-NAA software or by manual; (2) the detection efficiency calibration of gamma spectrometers used in k0-NAA, (3) the determination of reactor neutron spectrum parameters such as a and f factors and neutron fluxes in the irradiation channels, and (4) the validation of the developed k0-NAA procedure by analysing some SRMs, namely Coal Fly Ash (NIST-1633b), Bovine Liver (NIST-1577b) and IAEA-Soil7. The analytical results showed the deviations between experimental and certified values were mostly less than 15% with most Z-scores lower than 2. The k0-NAA procedure established at the Dalat research reactor has been regarded as a reliable standardization method of NAA and as available for practical applications, in particularly for airborne particulate and crude oil samples.
Authors:Nikolett Uzinger, Sándor Barna, and Attila Anton
L., 1999. Talajszennyeződés, talajtisztítás. Környezetügyi Műszaki Gazdasági Tájékoztató. Környezetgazdálkodási Intézet. Budapest.
, R. et al., 2005. Zeolite synthesis from pre-treated coalflyash