Thermal Neutron Activation Analysis Research Articles

Determination of cobalt by substoichiometric thermal neutron activation analysis

Determination of cobalt by substoichiometric thermal neutron activation analysis

放射化分析法によるブドウの各種元素含有量

放射化分析法によるブドウの各種元素含有量

Determination of thallium in biological samples by thermal neutron activation analysis and low-level beta-counting

A procedure is described for the determination of thallium in complex biological matrices by thermal neutron activation analysis employing substoichiometric extraction of thallium(I) with 2-mercaptobenzothiazole (2-HMBT) at a pH of 7.5 into chloroform, and low-level beta-counting.

Determination of palladium in alloys and ores by substoichiometric thermal neutron activation analysis

A rapid, selective and simple method have been developed for the determination of palladium in alloys and ores by thermal neutron activation analysis, incorporating substoichiometric solvent extraction of Pd/II/ with 1,2,3-benzotriazole /1,2,3-BT/ into methyl iso-butyl ketone /MIBK/. Two samples and a standard can be processed and counted within two hours.

Chromium, nickel, and arsenic determinations in human samples by thermal and epithermal neutron activation analyses

Both thermal and epithermal neutron activation analyses have been employed to determine chromium and nickel in lung tissue and arsenic in urine. Based on accuracy, precision, and detection limits, these techniques have been successfully used to analyze lung tissue from a deceased welder, who died, from cancer, and to paratake in an interlaboratory toxicological urine program.

Substoichiometric determination of Cd by neutron activation analysis

A rapid method has been developed for the determination of cadmium in environmental samples by thermal neutron activation analysis involving substoichiometric extraction with 1,2,3-benzotriazole /1,2,3-BT/. Cd was radiochemically separated as CdS using 1-amidino-2-thiourea. The time required for radiochemical purification containing two samples and a standard was about 2 h. 4.63 μg of Cd can be determined with an accuracy of 6.69% and precision of 6.25%. Mash potatoes, animal bones, raw sludge and cattle manure have been analyzed by this method.

A particle-size specific elemental mass balance for the apportionment of ambient aerosol

Photon and thermal neutron activation analysis were used to determine the concentrations of up to thirty elements in aerosol samples collected by cascade impactor in Toronto, Canada during the period July to December of 1985. Examination of the particle-size distributions thus obtained led to the development of a new receptor model. A size-specific elemental mass balance (SSEMB) was used to apportion the mean ambient Pb aerosol concentration amongst four contributing sources as follows: secondary lead refinery emissions (46%), refuse incineration (28%), automotive exhaust (25%) and re-entrained soil and dust (<1%). The predicted concentrations of Al, As, Br, Na, Pb, Sb, and Zn agreed with observed concentrations to within a factor of two for most elements in most particle size fractions.

The determination of tin in explosive materials by thermal neutron activation analysis

A method, based on the measurement of the γ-photopeak at 332 keV arising from a124Sn(n, γ)125mSn reaction, has been developed for the rapid measurement of Sn at concentrations of ∼20 μg g−1, present as the cross-linking agent, in explosive charges. The method is comparative, and has a limit of detection of ∼0.6 μg g−1 and a precision of ∼5% RSD. The method requires no sample preparation and is economical in effort.

Multi-element correlations for airborne particulate source attribution

Photon and thermal neutron activation analysis were used to analyze airborne particulate matter obtained during the period January to March of 1984 for up to thirty elements. Elemental concentrations and meteorological data from the Toronto, Ontario area were subjected to factor analysis and the major sources of particulate deduced. Elemental profiles for six sources, viz. crustal soil, automobile exhaust, road salt, refuse incineration, oil combustion and an unidentified arsenic source, were used in a chemical element balance to quantitatively determine the contribution of each source to the ambient aerosol. Re-entrained soil contributed 67%, automobile exhaust contributed 15% and the other sources contributed lesser amounts to the inorganic particulate matter. Particle-size distributions for nine elements, viz. Al, Fe, Sc, As, Br, Cl, Zn, Mn, V, are presented as an argument for the development of receptor models involving particle-size distribution data.

Distribution of Al, V, and Mn in lichens across Calcasieu Parish, Louisiana

The lichen Ramalina stenospora was collected from 16 location in Calcasieu Parish and from 2 locations in Cameron Parish in Southwestern Louisiana. The metals V, Mn, and Al were measured in lichen specimens collected during three seasons — fall 1983, winter and spring 1984. The metals were determined using thermal neutron activation analysis. Vanadium was found to range in concentration from 2.1 to 10 mg kg−1; and Al from 900 to 4500 mg kg−1. Metal concentration was found to decrease exponentially with distance outward from the industrial corridor. The major industries included were an Al plant, two refineries and five chemical plants mostly related to plastics production.

Determination of antimony in nail and hair by thermal neutron activation analysis

The concentration of antimony in nail and hair was determined by thermal neutron activation analysis. Samples were collected from the workers of an antimony refinery, inhabitants near the refinery, and residents in control area. They were irradiated by Kyoto University 5 000 kW Reactor for 1 h, and cooled for 30 to 100 days. After cooling, the concentration of Sb in nail and hair was estimated by measuring the intensity of gamma-ray from 124Sb of the samples, then the samples were washed by 0.1% aqueous solution of nonionic surface active agent in an ultrasonic cleaner. The gamma-ray spectrometry was done again (after washing). The concentration of Sb in nail before washing was 730 ppm for the workers, 2.46 ppm for habitants near the refinery, and 0.19 ppm for the control; after washing, it became 230 ppm for the workers, 0.63 ppm for habitants, and 0.09 ppm for the control. The concentration of Sb in hair before and after washing was 222 ppm and 196 ppm for the workers, and 0.21 ppm and 0.15 ppm for the control, respectively.

Spectral interferences from uranium fission in neutron activation analysis

The spectral interferences due to uranium fission in thermal neutron activation analysis (NAA) were determined for Ba, Cr, Ce, La, Mo, Nd, Ru, Sm, Te and Zr. For Ba, Mo, Te and Zr the interferences were also evaluated for epithermal NAA. The degree of interference was calculated in terms of the apparent ppm concentration of the element of interest per ppm of U. High U concentrations in geological material can severely hamper the analysis of all the elements (except Cr) by NAA.

THE ACCUMULATION AND DISTRIBUTION OF VANADIUM, IRON, AND MANGANESE IN SOME SOLITARY ASCIDIANS.

The vanadium, iron, and manganese contents of 15 species of solitary ascidians belonging to the suborders Phlebobranchia and Stolidobranchia were determined by thermal neutron activation analysis. Vanadium was detectable in all species examined. In general, the vanadium content in various tissues of the Phlebobranchia was considerably higher than the iron and manganese contents. The blood cells especially contained a large amount of vanadium. The highest value (21 µg vanadium/mg dry weight) was obtained from blood corpuscles of Ascidia ahodori. Species in the suborder Stolidobranchia, on the other hand, had smaller quantities of vanadium in comparison with those in the suborder Phlebobranchia. The iron and manganese contents did not differ greatly between the two suborders. The data are considered in the light of physiological roles of these transition metals in ascidians.

Substoichiometric determination of silver by Neutron Activation Analysis

A rapid and selective method has been developed for the determination of Ag in biological samples and mineral ores by thermal neutron activation analysis employing substoichiometric extraction with 1,2,3-benzotriazole /1,2,3-BT/ into chloroform. The time required for the radiochemical purification and counting of two samples was 1 h. 4.84 μg Ag can be determined with an accuracy of 7.44% and a precision of 3.57%.

Photoluminescence spectra of In-doped ZnSe single crystals

High-purity zinc selenide single crystals have been doped with indium in the concentration range from 0.03 to 30 p.p.m. by means of the vapour-phase transport technique. The concentration of indium has been precisely determined by thermal neutron activation analysis. The photoluminescence (PL) spectra measured at 4.2K show the I2 line, donor-acceptor pair emission lines and two broad emission bands around 1.98 and 2.20 eV. The emission intensities are found to be strongly affected by the native defect concentrations. The temperature dependence of the PL spectrum suggests that the 1.98 eV emission band is a self-activated emission related to an associated defect involving InZn and a zinc vacancy.

Determination of cadmium by substoichiometric thermal neutron activation analysis

A rapid and selective method has been developed for the determination of cadmium in environmental samples by thermal neutron activation analysis, employing substoichiometric solvent extraction technique. Alcoholic solution of 2-mercaptobenzothiazole /2-HMBT/ has been used for the substoichiometric extraction of Cd/II/ from an aqueous solution of pH 7.0 into methyl iso-butyl ketone /MIBK/.

Determination of selenium by substoichiometric thermal neutron activation analysis

Determination of selenium by substoichiometric thermal neutron activation analysis

Substoichiometric determination of Hg by radiochemical neutron activation analysis

A rapid method has been developed for the determination of mercury in environmental samples by thermal neutron activation analysis. Radiochemical separation involves the extraction of Hg/II/ with substoichiometric amounts of 2-mercaptobenzothiazole /2-HMBT/ into chloroform1. The time required for radiochemical purification and counting of two samples and a standard is about 2 h. Water, sludge and IAEA standard samples were analyzed for Hg concentration by this method.

Neutron activation analysis of manganese and nickel in commercial steel samples

The non-destructive thermal neutron activation analysis of some commercially available steel samples viz. SS-316, SS-310, SS-304, Tiscral, CA55 and EN 8 is carried out using a252Cf source. The manganese content of these steel samples is estimated by measuring the γ-activity of56Mn using a single channel analyzer on integration mode and a NaI/Tl/ detector as well as using a high purity germanium detector coupled to a 4K multichannel analyzer. The results obtained by both procedures show reasonable agreement with each other. The nickel content of the various steel samples is also estimated.

Instrumental determination of some trace elements in biological materials by epithermal and thermal neutron activation analysis.

The possibilities of increasing the utility of instrumental neutron activation analysis (NAA) of biomedical and environmental samples have been examined by introducing an epithermal neutron activation technique. The major advantage, in comparison with classical neutron activation methods, is found to be the reduction of interfering matrix activities, which allows the rapid instrumental determination of some trace elements of interest with minimum delay. The technique was evaluated using standard biological materials and the accuracy, precision, detection limits and the time scales of analysis were compared with those obtained using conventional thermal neutron activation. Results of the analysis of a mixture of plasma and erythrocytes are given to assess the method. The method can be applied to determine As, Br, Cd, Fe, Mn, Mo, Ni, Rb, Se, Sr and Zn in biological materials without chemical separation.