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1.
Trace elements in airborne particulate matter collected monthly at suburban and rural areas in Korea were analyzed by instrumental neutron activation analysis (INAA). Neutron irradiation of the samples was done at the irradiation hole (neutron flux 1·1013 n·cm–2·s–1) of the TRIGA Mark-III Research Reactor in the Korea Atomic Energy Research Institute. For the verification of the analytical technique, two reference materials, NIST SRM-1648 and NIES CRM-8, were chosen for analysis. The accuracy and precision of the determinations of the 40 elements were compared with the reference values. We used this method (1) to analyze 30 trace elements in airborne particulate matter collected monthly with the high volume air sampler (PM-10) at two different locations and (2) to confirm the possibility of using this method as a routine monitoring tool to find out environmental pollution sources.  相似文献   

2.
An instrumental neutron activation analysis technique has been developed for the determination of As, Au, Ba, Co, Cr, Fe, Hf, Sb, Ta, Th, U, W and Zn in large (10–15 g) geological samples using in-pool irradiation with a SLOWPOKE-2 reactor. The technique allows for the simultaneous irradiation of multiple samples using a neutron flux of between 4·1013 and 8·1013 n·m–2·s–1. The detection limits obtained using the analytical methodology described in this paper are acceptable for exploration geochemistry and the technique has been used to analyze samples collected as part of a metallic minerals survey of Jamaica.  相似文献   

3.
24 male autopsy cases aged 35–60 years have been collected from Shanghai China to study the relationships between human hair and internal tissues. Autopsy samples of hair, kidney-cortex, liver and lung were analyzed. A radiochemical neutron activation analysis (RNAA) based on a simple group extraction scheme was used for measuring the trace elements As, Cd, Hg, Cu and Zn. Zinc diethyldithiocarbamate Zn(DDC)2 and methly isobutyl ketone-iodide have been chosen as reagent. Trace element of Se was determined by instrumental neutron activation analysis (INAA). A SLOWPOKE reactor with a thermal neutron flux of 8·1011 n·cm–2·s–1 and a swimming pool type reactor with a thermal neutron flux of 1·1013 n·cm–2·s–1 were used for short and long irradiation of samples, respectively. The reliability of methods has been checked by analyzing biological standard reference materials Horse Kidney (IAEA H8), Tomato Leaves (NBS 1573) and Human Hair (NIES-5). The analytical results show that toxic elements As, Cd and Hg exist in a larger individual variability than the essential elements of Cu, Se and Zn for each tissue. A linear regression analysis related to the six elements of primary interest for the IAEA Coordinated Research Program (CRP) has been done by a computer program for each pair of hair-tissue. A positive correlation is found between concentration of As in hair and kidney-cortex, the correlation coefficient r is 0.751 (p<0.01). Positive correlations between concentration of Se in hair and liver, kidney-cortex and lung are also observed in this study. It shows that the elements As and Se in hair may be useful indicators for assessing certain internal tissues of normal persons. A comparison of Cd concentration in lung shows a significant difference between smokers and non-smokers. A significant correlation between element Cd and Zn in kidney-cortex is also presented in this paper.  相似文献   

4.
In the last years Cf-252 neutron sources will be incresingly used for nuclear analytical purposes. In the Central Institute of Isotope and Radiation Research, Leipzig, an irradiation equipment with a 3mg252Cf neutron source was constructed. It reaches thermal neutron fluxes of about 107 n·cm–2·s–1. The construction of this equipment and the different moderation geometries are described. Possibilities of the application for neutron induced autoradiography, neutron radiography and neutron activation analysis are demonstrated on examples.  相似文献   

5.
Elemental profiles of brain tumor tissues from 15 patients of astrocytomas (grade I–III) and normal human brain tissues of 23 male age matched autopsies as controls have been studied by instrumental neutron activation analysis. The SLOWPOKE reactor with a thermal neutron flux of 8·1011n·cm–2·s–1 and swimming pool type reactor with a thermal neutron flux of 1·1013n·cm–2·s–1 were used for short and long irradiation of samples, respectively. Spectrophotometry was only used for analyzing phosphorus. A total of 18 elements Se, Na, K, Br, Cl, Mn, Mg, S, Ca, Cu, Hg, Cr, Fe, Rb, Zn, Co, Sc and P has been determined for this purpose. The reliability of methods has been checked by analyzing biological standard reference materials horse kidney (IAEA H-8) and bovine liver (NBS SRM 1577a). The analytical results showed that compared with the normal brain tissues, concentrations of Ca, Fe, Cu, Zn, Se, Mn, Br and Sc were significantly higher in tumor tissues (P<0.01) and concentrations of Rb, K and P were lower, while no differences for contents of Mg, S, Cr, Hg, Na and Cl were observed. A negative correlation between P and Ca in malignant and normal brain tissues was observed.  相似文献   

6.
A pre-irradiation separation procedure has been developed for the determination of trace elements in high-purity scandium by neutron activation analysis. The sample is dissolved in high-purity concentrated hydrochloric acid and scandium is extracted with the same volume of a solution of 50 vol.% bis(2-ethyl hexyl)-orthophosphoric acid (HDEHP) in toluene. The scandium matrix is removed from the most important trace impurities and the residual amount of Sc is in the range of 0.001%. The separation is carried out in the vial to be used in irradiation to prevent sample contamination. Detection limits in the ppb range were achieved with a sample of 10 mg, a thermal neutron flux of 2 · 1013 n · cm–2 · s–1 and an irradiation time of 48 hours. Most of the elements sought in two samples of high-purity scandium were below the detection limits.  相似文献   

7.
The concentration of rare earths and other elements have been determined in the bed sediment samples of Karnafuli estuarine zone in the Bay of Bengal by instrumental neutron activation analysis (INAA). The samples and the standards soil-5, soil-7, coal fly ash and pond sediment were prepared and simultaneously irradiated for short and long time at the TRIGA Mark-II research reactor facility of Atomic Energy Research Establishment, Savar, Dhaka. The maximum themal neutron flux was of the order of 1013 n·cm–2·s–1. After irradiation the radioactivity of the product nuclides was measured by using a high resolution high purity germanium detector system. Analysis of -ray spectra and quantitative analysis of the elemental concentration were done via the software GANAAS, it has been possible to determine the concentration level of 27 elements including the rare earths La, Ce, Sm, Eu, Tb, Dy and Yb and uranium and thorium.  相似文献   

8.
Possible losses of seven chemical elements were investigated in biological tissues during freeze-drying in vacuum. Thyroid glands were taken during post-mortem examination of 23 people died of different diseases. Instrumental neutron activation analysis (INAA) was used to estimate contents of Br, Ca, Cl, I, K, Mg, and Na. The nuclear reator vertical channel with flux density of 1.2·1013n·cm–2·s–1 was used for neutron irradiation. The analysis was carried out using short-lived radionuclides induced in samples after neutron irradiation. Then thyroids were freeze-dried at below 0 °C in vaccum up to the constant mass (lyophilisation) and then homogenized. Samples of lyophilised and homogenized tissues were again studied by INAA. The lack of difference between the results of the analysis before and after lyophilisation is an evedence of no loss of Br, Ca, Cl, I, K, Mg and Na during freeze-drying of biotissues in vaccum.  相似文献   

9.
A prompt gamma neutron activation analysis (PGAA) setup installed at ANRTC has been used to analyze boron. It consists of a 22.6% REGe detector and a 740 GBq 241Am-Be neutron source moderated with water and paraffin. At the sample irradiation position, the thermal neutron fluence rate measured was 2.36·104 n·m–2· s–1 and the corresponding Cd-ratio was 22 for gold monitor. The absolute detection efficiency in the range of 120–1500 keV was determined using 152Eu standard solution. The sensitivity and detection limit for standard boric acid samples has been determined. The boron content in boric acid prepared from Turkish borate ores is measured to be 15.91±0.46% wt.  相似文献   

10.
A prompt gamma neutron activation analysis (PGAA) setup installed at ANRTC has been used to analyze boron. It consists of a 22.6% REGe detector and a 740 GBq 241Am-Be neutron source moderated with water and paraffin. At the sample irradiation position, the thermal neutron fluence rate measured was 2.36·104 n·m–2· s–1 and the corresponding Cd-ratio was 22 for gold monitor. The absolute detection efficiency in the range of 120–1500 keV was determined using 152Eu standard solution. The sensitivity and detection limit for standard boric acid samples has been determined. The boron content in boric acid prepared from Turkish borate ores is measured to be 15.91±0.46% wt.  相似文献   

11.
In determining the trace platinum group elements and gold in rocks and ores by the neutron activation analysis after a nickel sulphide fire assay preconcentration, there are interferences due to nuclides produced from second order nuclear reactions. This paper presents the degree of interference calculated over the ranges of long irradiation times and of reactor neutron flux from 1·1013 to 1·1015 n·cm–2·s–1. According to the results of these calculations, every one of the second order interfering reactions on the PGE+Au, except the197Au(n, )198Au(n, )199Au reaction, can be neglected under the long irradiation time or high reactor neutron flux. Special attention is given to the interference from gold in the determining platinum.  相似文献   

12.
The trace elements content of Cola acuminata and three varieties of Cola nitida have been determined using neutron activation analysis. The samples have been irradiated at the Joint Universities Research Reactor, Risley, England for 71/2 hours in a neutron flux of 2.5·1012 n·cm–2s–1 and analysed using high resolution lithium drifted germanium detector coupled to a Canberra 35 microprocessor as a 4096 channel gamma spectrometer. The elements: Na, K, Br, W, Fe, Cs, Co, Zn, and Sc were detected.  相似文献   

13.
Instrumental neutron activation analysis technique was applied for the determination of 20 elements in 54 silicate rock samples which belong to three sedimentary geological formations located in the western desert of Iraq. The samples along with USGS standards were irradiated in an IRT-5000 reactor at a neutron flux of 3.7·1013 n·cm–2·s–1 The following minor and trace element constituents have been determined: Na, K, Ca, Fe, Sc, Cr, Co, Zr, Ce, La, Nd, Sm, Eu, Tb, Yb, Lu, Hf, Ta, Th and U.  相似文献   

14.
Concentrations of Al, Br, Ca, Ce, Co, Cr, Eu, Fe, Hf, La, Lu, Mg, Mn, Na, Rb, Sc, Sm, Sr, Tb, Th, Ti, V, Yb, Zn, and Zr have been measured in Tigris and Euphrates river water, using neutron activation analysis in combination with preconcentration technique. River water samples were preconcentrated by evaporation at 70°C under atmospheric pressure. The samples with standard reference materials were irradiated with a neutron flux of 2.3·1013 n·cm–2·s–1.  相似文献   

15.
An epithermal energy neutron irradiation facility has been used to perform instrumental activation analysis for iodine, silicon, nickel, zirconium, uranium and thorium. The facility, which is adjacent to the fuel of the University of Virginia 2.0 MW pool reactor, consists of a dry sample region surrounded by a fixed cadmium shield. A boron nitride capsule can be used to hold the sample in the cadmium facility to further enhance the reduction of thermal neutron activation. The neutron fluence rate is 2.2×1016 n·m–2·s–1 for fission spectrum energy neutrons (measured with Ni(n,p)Co) and 8.2·1015 n·m–2·s–1 for resonance energy neutrons (measured with gold).Iodine has been measured at concentrations as low as 0.1 mg/kg with 3% counting statistics in powdered infant formula and 0.15 mg/kg with 5% statistics in liquid infant formula. Silicon has been measured at concentrations of 0.2% in biological samples with counting statistics between 5 and 10% and in coal and soil at concentrations greater than 4% with better than 1% statistics. Nickel has been measured in coal and soil at the 20 mg/kg level and higher with 6% statistics. Zirconium has been determined at 600 mg/kg and greater in ceramics with counting errors less than 3%. Uranium and thorium have been measured at the 10 mg/kg level with 3% counting statistics.  相似文献   

16.
A neutron activation method for determination of uranium dissolved in the coolant of the first cycle of nuclear power stations is proposed. The method is based on preliminary concentration on activated carbon, irradiation with epithermal neutrons and gamma-spectrometry of239Np. The detection limit amounts to 1,3·10–8 U/l. The method was sucessfully applied for the determination of uranium in the coolant of a nuclear power station.  相似文献   

17.
Summary A simple method is decribed for instrumental multielement thermal neutron activation analysis using a monostandard. For geological and air dust samples, iron is used as a comparator, while sodium has advantages for biological materials.To test the capabilities of this method, the values of the effective cross sections of the 23 elements determined were evaluated in a reactor site with an almost pure thermal neutron flux of about 9·1012 n·cm–2·s–1 and an epithermal neutron contribution of less than 0.03%. The values obtained were found to agree mostly well with the best literature values of thermal neutron cross sections. The results of an analysis by activation in the same site agree well with the relative method using multielement standards and for several standard reference materials with certified element contents. A comparison of the element contents obtained by the monostandard and relative methods together with corresponding precisions and accuracies is given.
Die Monostandardmethode bei der Aktivierungsanalyse mit thermischen Neutronen von geologischem, biologischem und Umweltmaterial
Zusammenfassung Die Monostandardmethode wurde erstmals auf die Aktivierungsanalyse mit rein thermischen Neutronen aus der thermischen Säule des Reaktors FRJ-2 (mit epithermischen Anteilen von < 0,03%) angewendet. Hier sind die theoretischen Verhältnisse und damit auch Gleichungen besonders einfach. — Die bei einem Neutronenfluß von 9·1012 n·cm–2·s–1 ermittelten effektiven Neutroneneinfangquerschnitte stimmen häufig gut mit den Literaturwerten überein. — Für geologische Proben wurde Eisen, für biologisches Material Natrium als Komparator, d.h. Monoelementstandard, verwendet. Es konnten über zwanzig Elemente in Andesit, Granit, Flugstaubasche, Luftstaub, Pflanzenmaterial und Obstblättern bestimmt werden.


Dedicated to Professor Dr. Kurt Starke, University of Marburg/ Lahn on the occasion of his 70 th birthday

Fourth Communication on Improvement of Instrumental Analysis for Service Analysis

Guest Scientist from Egypt.

Guest Scientist under IAEA-Fellowship from the Faculty of Chemistry, University of Sofia, Bulgaria

This paper is an extract of the more detailed Report Jül-1822 (ISSN 0366-0885), January 1983.  相似文献   

18.
The analytical potential of a fast neutron reactor has been studied. The maximum density of the neutron flux is 2.5·1015 cm–2·s–1 at a maximum energy of 450 keV. The determining reaction for activation analysis at this reactor is an (n, n) reaction. The possibility of selectively determining Pb, Hg, Cd, Au, Ag and other elements at a level of 10–5–10–8% is demonstrated. This activation technique allows rapid determination of these elements.  相似文献   

19.
The use of instrumental neutron activation analysis (INAA) in determining selected elements in biological materials has been reported by numerous authors. Some of these have detailed the use of INAA to determine an elemental analysis in tobaccos of various geographical origins. This paper describes the first use of INAA to measure the distribution of selected inorganic elements within the tobacco leaf at a single plant stalk position for one tobacco curing routine. Three replicate plots of a common bright tobacco cultivar were grown under normal cultural conditions characteristic for the bright variety. The tobacco leaves were sampled at selected positions in the leaf. The brigh tobacco was cured in a conventional flue-curing barn using standard practices. Immediately after collection, each individual sample was freeze-dried, crushed and sampled. The leaf midrib samples were prepared using a similar procedure. A subsample of about 100 mg was taken from each sample, sealed in a polyethylene bag, irradiated in a thermal neutron flux of 2×1017 n·m–2·s–1 in a pneumatic rabbit system, and subsequently counted to obtain the reported data. A standard reference material was used as a comparator to yield relative elemental concentrations for Ca, Mg, Mn, Na, K, Cl and Br. The data show that chlorine, potassium, sodium and calcium have definite concentration trends within the tobacco leaf. The data also show that some elements, e.g. Mn, were more uniformly distributed throughout the leaf.  相似文献   

20.
The application of stable isotope analysis using neutron-induced prompt -ray analysis (PGA) with cold/thermal neutron beams for the tracer study of geological materials are discussed. Silicon has three natural isotopes differing in abundance:28Si (92.23%),29Si (4.67%) and30Si (3.10%). For the purpose of the assessment of Si migration in engineered barrier material, enriched30Si can be used as a tracer due to its nuclear and chemical properties. Isotope analysis of30Si was performed by PGA during the tracer study. Neutron intensity at the sample position was 1.4·108 n¢cm–2·s–1, 2.4·107 n·cm–2·s–1 for cold and themal neutron guided beams of JRR-3M, respectively. Calibration curves and analytical sensitivity of30Si were determined based on measurement of standard samples. BG and detection limits for30Si analysis were also measured in Japanese bentonite (Kunigel V1 and Kunipia F) and their pore water. Fiffteen elements were determined simultaneously using PGA.  相似文献   

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