共查询到20条相似文献,搜索用时 11 毫秒
1.
S. Chhillar R. Acharya R. K. Mishra C. P. Kaushik P. K. Pujari 《Journal of Radioanalytical and Nuclear Chemistry》2017,312(3):567-576
Particle induced gamma-ray emission (PIGE) method using 4 MeV proton beam was utilized to analyze two types of barium borosilicate glass (BaBSG) samples for quantification of concentrations of low Z elements. The in situ current normalization method was applied in the analysis of eight samples containing varying concentration of F along with Si, B and Na. Charge normalized PIGE method was applied to determine concentrations of above low Z elements including Li and Al in samples having simulated nuclear waste from reprocessing of thoria spent fuel. Synthetic samples and NIST SRMs were used for method validation. 相似文献
2.
A. Srivastava S. Chhillar D. Singh R. Acharya P. K. Pujari 《Journal of Radioanalytical and Nuclear Chemistry》2014,302(3):1461-1464
A non-destructive, in situ current normalized particle induced gamma-ray emission methodology has been standardized for quantification of fluorine (F) in soil samples from Punjab state, India. The samples were irradiated using 4 MeV proton beam from the Folded Tandem Ion Accelerator at BARC, Mumbai. The gamma rays of energies 197 and 478 keV arising from 19F(p, p′γ)19F and 7Li(p, p′γ)7Li nuclear reactions were measured using high resolution gamma-ray spectrometry. The concentration of fluorine in soil samples was found to vary between 414 and 5,746 mg kg?1. 相似文献
3.
S. Chhillar R. Acharya R. V. Pai S. Sodaye S. K. Mukerjee P. K. Pujari 《Journal of Radioanalytical and Nuclear Chemistry》2012,293(1):437-441
A particle induced gamma-ray emission method using proton beam in conjunction with in situ current normalization approach was standardized for non-destructive determination of low Z element lithium and was applied for quantification of Li in lithium doped neodymium dititanate (Nd2Ti2O7) ceramic sample. Thick pellets of heat treated samples, their precursors and Li standards were prepared separately by homogeneously mixing with cellulose and fixed amount of F used for in situ current normalization. For validation of the method, four synthetic samples were also analyzed. Samples and standards were irradiated with 4?MeV proton beam (~5?nA current) from folded tandem ion accelerator (FOTIA) BARC, Mumbai. Characteristic ??-rays of 478?keV from 7Li to 197?keV from 19F were measured by high resolution ??-ray spectrometry. The Li concentrations determined in the six samples were in the range of 0.29?C0.85?wt%. The Li contents in heat treated samples gave the idea about loss of Li compared to their precursors. 相似文献
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5.
Manfred Sager 《Monatshefte für Chemie / Chemical Monthly》1987,118(1):25-29
A rapid method for the determination of fluorine in various matrices of geochemical and environmental interest is described. After fusion with NaOH, the sample is dissolved by means of tiron (= pyrocatechol-3,5-disulfonic acid, disodium salt), which acts both as buffer substance and as superior masking agent for cations exhibiting strong complexes with fluoride, e.g. Al, Fe, Ti etc. The final determination is done by means of the fluoride sensitive electrode without further separation.The applicability of the method has been checked for various silicates, bauxite, phosphates, soils, coal and plant material. A detection limit of 10 µg/g can be achieved, which is sufficient in many cases. The overall precision is better than ±10%.Dedicated to Prof. Dr.K. L. Komarek on occasion of his 60th birthday. 相似文献
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7.
Chaturvedula S. Sastri Karl P. Schelhaas 《Fresenius' Journal of Analytical Chemistry》1982,321(8):739-747
Summary A non-destructive multi-element method based on nuclear reactions and Coulomb excitation induced by alpha-sources and the measurement of prompt gamma-rays is described. The method is suitable for light and medium Z elements and is particularly sensitive to light elements. The experimental set-up necessary for the prompt measurements is quite simple. With 0.34 mCi 241Am source, the sensitivity of the method is discussed for the light elements Li, Be, F and Na. The influence of sample size, air pressure etc. on the thick target yield has been investigated. Monte-Carlo calculations have been performed to study the modification of the isotropic behaviour of the alpha-source due to the protective covering and to calculate the average energy loss. The lithium determination in some minerals has been carried out.
Analytische Anwendung der -induziertcn -Emission
Zusammenfassung Eine zerstörungsfreie Multielement-methode, die auf Kernreaktionen und Coulombanregung induziert durch -Quellen beruht, sowie die Messung prompter -Strahlung werden beschrieben. Die Methode eignet sich für leichte und mittelschwere Elemente und ist besonders empfindlich bei leichten Elementen. Der für Promptmessungen notwendige experimentelle Aufbau ist recht einfach. Die Empfindlichkeit der Methode bei Benutzung eines 0,34 mCi starken 241Am-Präparats wird für die leichten Elemente Li, Be, F und Na diskutiert. Der Einfluß von Probengröße, Luftdruck usw. auf die Ausbeute eines dicken Targets wurde untersucht. Monte-Carlo-Rechnungen wurden ausgeführt, um die Modifizierung der isotropen Abstrahlung der Quelle durch deren Schutzabdeckung zu studieren und um den mittleren Energieverlust zu erhalten. Eine Li-Bestimmung in einigen Mineralen wurde durchgeführt.相似文献
8.
M. Spychala W. Michaelis H. -U. Fanger 《Journal of Radioanalytical and Nuclear Chemistry》1987,112(2):331-339
A facility for the irradiation of internal targets has been installed at the research reactor FRG-of the GKSS Research Center. Thermal-neutron induced prompt gamma radiation was detected by pair spectrometer. With this experimental arrangement concentrations of the major and mino elements Na, Al, Si, K, Ca, Ti, Mn, Fe, Zn, Cl, and S, as well as of the trace constituents Cr Ni, Cu Cd, and Hg of samples from a sediment core of the Elbe River could be determined. The results indicate, that prompt gamma-ray neutron activation analysis (PGNAA) is a powerful instrumental tool for a complete characterization of the main sediment constituents and for the detection of the trace elements Cd and Hg which are of considerable ecological relevance. 相似文献
9.
A procedure is described for the precise determination of fluorine in organic and metal-organic compounds by 14-MeV neutron activation analysis using the reaction: 19F(n,2n)18F (β +, t = 110 min).A relative standard deviation of better than ±0.5% is achieved by irradiating samples and standard simultaneously. Uniform neutron exposures were ensured by rotating the samples during irradiation. Positron emitters of short half-life are allowed to decay before counting. In metal-organic compounds, Sc, Zn, Ga and Ag cause the most serious interference; for organic compounds the method is rapid, and specific for fluorine. 相似文献
10.
The direct non-destructive proton-induced gamma-ray emission (PIGE) technique with a germanium detector was applied to the determination of total fluorine concentration in five coal reference materials (BCR 40, NIST 1632b, NIST 1635, SARM 20 and USGS CLB-1). Duplicate analyses were made from five randomly selected bottles of each coal. Individual data are presented and some problems (calibration, proton stopping power, effects of sample heating by the proton beam, background estimation) which were encountered during this study are discussed. Sensitivity and reproducibility of the determinations, and homogeneity of the coal samples with respect to fluorine contents by analysis of variance were investigated. The present data are also compared with the few published values for these reference samples, including other PIGE data. The use of synthetic standards and spiked samples in the present study suggested that the PIGE method was more accurate than other techniques. 相似文献
11.
M. Hyvönen-Dabek 《Journal of Radioanalytical and Nuclear Chemistry》1981,63(2):367-378
Proton-induced prompt gamma-ray emission (PIGE) analysis has been used for the determination of light elements in human dense
bone samples. Li, B, N, O, F, Na, Mg, Al, P and Ca peaks were detected. Smoothed, freeze-dried samples were irradiated in
vacuo by 2.4 MeV protons and the induced prompt gamma rays recorded with a 110 cm3 Ge(Li) detector. Absolute concentrations were calculated on the basis of both calibration standards and pure element gamma-ray
yields. The mean (±1 S. D.) concentrations as ppm or weight % obtained for 15 dense bone samples were: B 8.0 (3.3)ppm, N 12.2
(0.8)%, O 34.8 (2.3)%, F 639 (417)ppm, Na 5763 (371)ppm, Mg 2078 (290)ppm, P 9.26 (0.50)% and Ca 20.4 (1.3)%. The detection
limits obtained without any prior concentration of the bone samples were: 0.3 ppm for Li, 2.0 ppm for B, 1.0% for N, 1.0%
for O, 1.0 ppm for F, 3.0 ppm for Na, 50 ppm for Mg, 22 ppm for Al, 600 ppm for P and 0.8% for Ca. Detection limits for other
light elements (4≤Z≤21) have also been estimated. 相似文献
12.
G. L. Bhale K. H. Ayyar P. M. R. Rao R. C. Naik 《Fresenius' Journal of Analytical Chemistry》1978,293(3):223-224
13.
W. V. Prestwich T. J. Kennett 《Journal of Radioanalytical and Nuclear Chemistry》1979,50(1-2):249-259
A technique for the assay of radium by detection of coincident γ-radiation is evaluated. The sensitivity of various counting
modalities is compared. The influence of finite sample size and density is discussed. Interference from other natural radioactivities
is investigated and it is shown that a two channel arrangement is sufficient to take this into account. 相似文献
14.
Kudo Takuto Ninomiya Kazuhiko Strasser Patrick Terada Kentaro Kawai Yosuke Tampo Motonobu Miyake Yasuhiro Shinohara Atsushi Kubo Kenya M. 《Journal of Radioanalytical and Nuclear Chemistry》2019,322(3):1299-1303
Journal of Radioanalytical and Nuclear Chemistry - Variations in isotopic abundance provide useful information for various scientific fields. Herein we performed a feasibility study by... 相似文献
15.
Rutherford back-scattering of α-particles is used to determine trace amounts of thin films of platinum. The method is sensitive to 0.3 ng of platinum and the response is linear from at least 0.01 to 80 μg Pt cm-2 of substrate surface area. Calibration with weighed standards reveals good accuracy and precision throughout the linear range. Up to at least 80 μg cm-2, no matrix effects can be observed for platinum determinations on Mylar, carbon, glass, and glass or quartz coated with up to 0.5 μm thicknesses of tin oxide. Particle-induced x-ray emission spectra are included to show their utility in surface composition analysis. The analytical procedure for the determination of platinum is rapid and non-destructive, and requires minimal sample preparation. 相似文献
16.
A. A. Ramos S. Ohde S. Sirirattanachai A. Snidvongs 《Journal of Radioanalytical and Nuclear Chemistry》2003,257(2):441-444
A rapid non-destructive technique has been proposed for the determination of fluorine in coral skeletons by thermal neutron activation analysis, using the short half-life 20F nuclide (11.0 s). About 0.2-0.5 g samples were irradiated for 10 seconds in a Triga Mark II Reactor. Soon after the irradiation (25-35 s), measurements of -rays were performed with each sample and standard. The method has the drawback of low sensitivity (20 ppm of F), and the manual operation employed in the cooling step could lead to less precise measurements. We determined fluorine in coral standards within ~8% of analytical precision. The result obtained for the dolomite standard was fairly consistent with literature values, but those for the limestone standard showed to be considerably higher than the reported values. The present method was applied for the determination of fluorine in modern corals from Khang Khao Island, Thailand and Okinawa, Japan. Two core samples of an ancient reef from Funafuti Atoll were measured for fluorine to compare with modern samples. In order to understand the environmental media in which coral grew, the partition of fluorine between seawater and coral skeletons is also discussed. 相似文献
17.
Particle induced X-ray emission (PIXE) and Rutherford backscattering spectrometry (RBS) were used to determine the concentrations
of trace elements in samples of 12 tomato puree brands sold in the Mexican market. While RBS offered information about the
main elements present in the matrix, PIXE gave results on trace elements. As a whole, data for 17 elements (C, N, O, Na, Mg,
S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, and Zn) were obtained. To evaluate the results, a comparison with brands from USA,
Japan, Colombia, and Chile was carried out, using tomato purees produced following the domestic technology recipe. Additionally,
the results were considered in the light of the Codex Alimentarius and the Mexican standard. It was found that all of the
brands fall within the limits established by these standards, being of the same order of magnitude as the foreign brands.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
18.
Fluorine determination in human and animal bones by particle-induced gamma-ray emission 总被引:1,自引:0,他引:1
Sastri CS Iyengar V Blondiaux G Tessier Y Petri H Hoffmann P Aras NK Zaichick V Ortner HM 《Fresenius' Journal of Analytical Chemistry》2001,370(7):924-929
Fluorine was determined in the iliac crest bones of patients and in ribs collected from post-mortem investigations by particle-induced gamma-ray emission based on the 19F(p,p'gamma)19F reaction, using 2.0/2.5 MeV protons. The results indicate that for 68% of the human samples the F concentration is in the range 500-1999 microg g(-1). For comparison purposes fluorine was also determined in some animal bones; in some animal tissues lateral profiles of fluorine were measured. 相似文献
19.
Ch. S. Sastri Venkatesh Iyengar Gilbert Blondiaux Yves Tessier Hermann Petri Peter Hoffmann Namik K. Aras Vladimir Zaichick Hugo M. Ortner 《Analytical and bioanalytical chemistry》2001,370(7):924-929
Fluorine was determined in the iliac crest bones of patients and in ribs collected from post-mortem investigations by particle-induced gamma-ray emission based on the 19F(p,p′γ)19F reaction, using 2.0/2.5 MeV protons. The results indicate that for 68% of the human samples the F concentration is in the range 500–1999 μg g–1. For comparison purposes fluorine was also determined in some animal bones; in some animal tissues lateral profiles of fluorine were measured. 相似文献
20.
A fast non-destructive determination of fluorine in bone samples by thermal neutron activation analysis using19F(n, γ)20F reaction was developed. About 0.1–1 g samples is irradiated for 15 sec in TRIGA MARK II reactor at a thermal neutron flux
of 5·1011 n·cm−2·sec−1. After 15–25 sec cooling, the 1633 KeV20F activity (T=11.2 sec) is counted for 15 sec with a Ge(Li) spectrometer. A standard sample is prepared by mixing CaF2 and CaCO3 powders. The interference from23Na(n, α)20F is corrected by employing24Na 2754 KeV double escape peak activities in samples and the20F/24Na peak area ratio observed previously for pure Na2CO3 powder. The precision is 7% for a bone sample containing 1020 ppm F and the sensitivity is about 10 ppm F. 相似文献