Neutron activation trace element analyses

Protection Agency (EPA) (4). Several techniques were used to analyze 101 coals, mostly from Illinois, for 23 trace elements. Neutron activation analysis (NAA) was used to determine several of the elements. 

The information on the chemical speciation of trace elements in biological systems is much needed to evaluate their biological significance. Although a number of analytical techniques based on atomic behavior are available for the analysis of chemical speciation of trace elements, neutron activation analysis, as a nuclear analytical technique, can be successfully used in chemical speciation studies, after appropriate fractionation steps. Table 2.5 lists some typical applications of NAA in chemical speciation analysis of metalloproteins. The main advantages of NAA are of its high sensitivity and the absence of matrix effects inherited from the conventional neutron activation analysis. It can, therefore, be used to analyze the chemical species of trace elements in very small samples or complicated matrices, which is often impossible for non-nuclear techniques. 

Applications to neutron activation analysis constitute another important use of Cf neutron sources. Neutron capture in many elements forms radioactive species that then decay with highly characteristic gamma-ray emissions. This analytical procedure is very sensitive and specific, and is widely used for the analysis of trace elements. Neutron activation finds use in uranium borehole logging to make accurate determinations of the uranium concentrations in boreholes as little as 100 parts per million of UaOg can be detected by this procedure. Other industrial uses for Cf sources are in the continuous monitoring of the sulfur and ash content of coal on a moving conveyor belt at the rate of SO tons per hour. Batch analysis of the vanadium content of crude oil is still another application of neutron activation analysis. 

MetaUic impurities in beryUium metal were formerly determined by d-c arc emission spectrography, foUowing dissolution of the sample in sulfuric acid and calcination to the oxide (16) and this technique is stUl used to determine less common trace elements in nuclear-grade beryUium. However, the common metallic impurities are more conveniently and accurately determined by d-c plasma emission spectrometry, foUowing dissolution of the sample in a hydrochloric—nitric—hydrofluoric acid mixture. Thermal neutron activation analysis has been used to complement d-c plasma and d-c arc emission spectrometry in the analysis of nuclear-grade beryUium. 

Byrne AR, Deemelj M, Kosta L, and Tusek-Znidaric M (1984) Radiochemical neutron activation analysis in standardization of trace elements in biological reference materials at the nanogram level. Mikrochim Acta [Wien] 1 119-126. 

Delfanti R, Di Casa M, Gallorini M, and Orvini E (1984) Five years activity in determining trace elements for the certification of standard reference materials by neutron activation analysis. Mikrochim Acta [Wien] L239-250. 

Heydorn K (1984) Neutron Activation Analysis for Chemical Trace Element Research. CRC Press, Boca Raton, Florida. 

Iieser et al. [628] studied the application of neutron activation analysis to the determination of trace elements in seawater. The rare earths included in this study were cerium and europium. The element concerned were adsorbed onto charcoal. Between 75% and 100% of the elements were adsorbed onto the charcoal which was then subjected to analysis by neutron activation analysis. Cerium (300 p,g/l) and europium (0.00082 pg/1) were found in North Sea water by this method. 

Holzbecker and Ryan [825] determined these elements in seawater by neutron activation analysis after coprecipitation with lead phosphate. Lead phosphate gives no intense activities on irradiation, so it is a suitable matrix for trace metal determinations by neutron activation analysis. Precipitation of lead phosphate also brings down quantitatively the insoluble phosphates of silver (I), cadmium (II), chromium (III), copper (II), manganese (II), thorium (IV), uranium (VI), and zirconium (IV). Detection limits for each of these are given, and thorium and uranium determinations are described in detail. Gamma activity from 204Pb makes a useful internal standard to correct for geometry differences between samples, which for the lowest detection limits are counted close to the detector. 

Karbe, L., C. Schnier, and H.O. Siewers. 1977. Trace elements in mussels (Mytilus edulis) from coastal areas of the North Sea and the Baltic. Multielement analysis using instrumental neutron activation analysis. Jour. Radioanal. Chem. 37 927-943. 

Nadkami, R.A. and W.D. Ehmann. 1970. Trace element determination in biological materials by neutron activation analysis. Pages 407-419 in D.D. Hemphill (ed.). Trace Substances in Environmental Health IV. Univ. Missouri, Columbia. 

Tijoe, P.S., J.J.M. de Goeij, and M. de Bruin. 1977. Determination of Trace Elements in Dried Sea-Plant Homogenate (SP-M-1) and in Dried Copepod Homogenate (MA-A-1) by Means of Neutron Activation Analysis. Interuniv. Reactor Inst. Rept. 133-77-05, Delft, Nederlands 14 pp. 

Nixon277 compared atomic absorption spectroscopy, flame photometry, mass spectroscopy, and neutron activation analysis as methods for the determination of some 21 trace elements (<100 ppm) in hard dental tissue and dental plaque silver, aluminum, arsenic, gold, barium, chromium, copper, fluoride, iron, lithium, manganese, molybdenum, nickel, lead, rubidium, antimony, selenium, tin, strontium, vanadium, and zinc. Brunelle 278) also described procedures for the determination of about 20 elements in soil using a combination of atomic absorption spectroscopy and neutron activation analysis. 

Study of chemical pathways in method development. Isotope dilution methods. Radioimmunoassay very important in biochemistry and medicine. Neutron activation analysis used for trace elements in geo-chemistry, semiconductor technology, pollution studies and forensic science. Relative precision of counting 1% if 104 counts are recorded. Assessment of pollution by radionuclides. 

Neutron activation analysis is an attractive method in many trace element problems, or where the total amount of sample is limited. Many geochemical studies of trace constituents and semi-conductor developments have used the technique, whilst in recent years pollution investigations have provided a new focus. In forensic science small flakes of paint, single hairs and a variety of other small samples have been analysed and identified by activation analysis. In recent years activation analysis has lost further ground to ICP-MS which provides more comprehensive information and is more readily operated. Sensitivity is also comparable in many cases. 

Salmon, L., Instrumental Neutron Activation Analysis in Environmental Studies of Trace Elements, AERE-R 7859, HMSO, 1975. 

Emeleus, V.M. (1958). The technique of neutron activation analysis as applied to trace element determination in pottery and coins. Archaeometry 1 6-15. 

Studies of the inorganics in cotton dust have incorporated the use of a wide variety of techniques. These include X-ray fluorescence spectroscopy, atomic absorption spectroscopy, electron microscopy, energy dispersive analysis of X-rays, X-ray diffraction, atomic absorption spectroscopy, neutron activation analysis and petrographic microscopy. It is necessary to use a wide array of techniques since no single technique will permit the measurement of all trace elements. Steindard chemical techniques to determine the ash content of samples and of various extracts have also been used. In most of these studies the ash fraction has been considered to be a reasonably accurate measure of the inorganic content. 

Cluster analysis Is used to determine the particle types that occur in an aerosol. These types are used to classify the particles in samples collected from various locations and sampling periods. The results of the sample classifications, together with meteorological data and bulk analytical data from methods such as instrunental neutron activation analysis (INAA). are used to study emission patterns and to screen samples for further study. The classification results are used in factor analysis to characterize spatial and temporal structure and to aid in source attribution. The classification results are also used in mass balance comparisons between ASEM and bulk chemical analyses. Such comparisons allow the combined use of the detailed characterizations of the individual-particle analyses and the trace-element capability of bulk analytical methods. 

Lambert JPF, Wilshire FW. 1979. Neutron activation analysis for simultaneous determination of trace elements in ambient air collected on glass-fiber filters. Anal Chem 51 1346-1350. 

Munita CS, Mazzilli BP. 1986. Determination of trace elements in Brazilian cigarette tobacco by neutron activation analysis. J Radioanal NucI Chem 108 217-228. 

The element may be analyzed in aqueous acidified phase by flame and furnace atomic absorption, ICP emission and ICP-MS spectroscopic methods. Also, at trace concentrations the element may be measured by x-ray fluorescence and neutron activation analysis. Wavelength for AA measurement is 240.7 nm and for ICP analysis is 228.62 nm. 

Gold may be identified by its physical properties. Trace quantities of gold may be analyzed by flame atomic absorption spectrophotometry (to 1 ppm) or by neutron activation analysis (to 1 ppb). The metal may be dissolved in aqua regia and the solution diluted appropriately prior to analysis. The most sensitive wavelength for this element is 242.8nm. 

Landsberger S, Jervis RE, Kajrys G, et al. 1983. Characterization of trace elemental pollutants in urban snow using proton induced x-ray emission and instrumental neutron activation analysis. Int J Environ Anal Chem 16 95-130. 

First, we analyzed samples for a large number of elements to Identify any elements, regardless of toxicity or typical concentration, that would provide signals for the presence of material from certain types of sources. Both ambient samples and particles from sources were analyzed by Instrumental neutron activation analysis (INAA), by which one can often measure about 35 elements In Individual samples (17), As the Important elements Pb, N1 and Cd are not consistently, If ever, observed by INAA, they were often measured by other methods. As INAA Is sensitive to very small amounts of obscure elements, we have obtained reliable data for elements such as Ga, Hf, Sc, In, W and many rare earths which pose no known health hazard at present levels and contribute Insignificant amounts of mass to TSP. However, as discussed below, many trace elements have already been shown to be Important In receptor... 

We have operated the University of Washington MKV impactor as a low-pressure impactor to provide for chemical analysis, four discretely sized fly-ash fractions in the sub-half-micrometer- diameter aerosol accumulation region. Instrumental neutron activation analysis provided the sensitivity to determine accurately the concentrations of 28 major, minor, and trace elements with sufficient precision to reveal fine structure in the elemental distributions that might be missed by techniques of lesser accuracy and precision. 

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