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2.
H. Higuchi K. Tomura H. Hamaguchi 《Journal of Radioanalytical and Nuclear Chemistry》1970,5(2):207-222
A Ge(Li) detector combined with cation exchange separation has been used for the determination of 12 rare-earth elements (La,
Ce, Nd, Sm, Eu, Gd, Tb, Ho, Er, Tm, Yb, and Lu) in rock samples by neutron activation analysis. After purification by the
conventional hydroxide-fluoride precipitation, the rare-earth elements are separated into two fractions, light (La-Tb) and
heavy (Ho-Lu), by EDTA cation exchange, and the γ-activities of the two fractions are measured by a Ge(Li) detector. The heavy
rare-earths, such as Ho, Er, and Tm, can be easily γ-counted without serious interference from the intense Compton background
and photopeaks due to the light rare-earths such as140La,153Sm,152Eu, and160Tb. The chemical yields (60%) for the individual rare-earths are determined by a reactivation technique. The results obtained
for the U.S. Geological Survey standard rocks G-1 and W-1 are compared with the previously reported data. 相似文献
3.
A neutron activation method for the rapid determination of dysprosium in rocks, based on simple chemical separation and γ-spectrometry with a lithiumdrifted germanium detector, is described. The 94.7-keV photopeak of dysprosium-165 (2.3 h half-life) was measured. Several geochemical standard rocks covering a variety of rock types were analyzed. The detection limit was 0.005 μg of dysprosium. A precision of ±4.7% was obtained on 7 separate analyses of a basalt standard rock. The accuracy of the method is discussed. 相似文献
4.
Keung-Shik Park Nak Bae Kim Hyung Joo Woo Kil Yong Lee Wan Hong Sang Ki Chun 《Journal of Radioanalytical and Nuclear Chemistry》1992,160(2):529-538
For the separation of rare-earth elements from steel, with a cation exchange resin, separation experiments were performed on NIST reference materials of SRM-363 and SRM-364. Iron, Na, Cr, Mn, Co, Cu, As, Mo, Sb and W were separated in 2M hydrochloric acid, five rare-earth elements, La, Ce, Pr, Nd and Sm and three other elements, Hf, Zr and Ba were separated using 8M nitric acid. Each element was determined by a single comparator method using two monitors, gold and cobalt. 相似文献
5.
M. Takeda H. Minowa M. Ebihara 《Journal of Radioanalytical and Nuclear Chemistry》2007,272(2):363-369
A simple and effective radiochemical procedure for radiochemical neutron activation analysis (RNAA) of ultra-trace siderophile
elements (Ru, Re, Os and Ir) and rare earth elements (REEs) in rock and meteorite samples is presented. To design the procedure,
several separation schemes of siderophile elements were examined by using radioactive tracers. By applying the procedure to
rock and meteorite samples, we have determined Ru, Re, Os, Ir and REEs, and confirmed that our values were in agreement with
the literature values. Our detection limits for Ru, Re, Os, La, Sm and Eu are significantly low compared with those for ICP-MS. 相似文献
6.
A rapid, selective and simple method has been developed for the determination of Sc in rock samples by thermal neutron activation analysis, employing substoichiometric solvent extraction of Sc(III) with alizarin into 1-octanol. Two samples and a standard can be processed and counted within three hours. 相似文献
7.
An instrumental neutron activation analysis (INAA) method has been developed for multi-element determination in geological
samples. The INAA method consists of irradiation of samples for 90 sec at a flux of 1.0·1012 n·cm−2·sec−1 and determination of 12 elements by using their short-lived nuclides. Samples have been re-irradiated for 3 hrs for measuring
concentrations of another 10 elements. Precision and accuracy of the INAA method have been evaluated by analysing samples
and USGS standard reference materials. Precision and accuracy are within±15% and ±10%, respectively. 相似文献
8.
S. Aizawa 《Journal of Radioanalytical and Nuclear Chemistry》2008,278(2):349-352
Twenty elements (Sm, U, As, Sb, La, Ce, Yb, Th, Cr, Eu, Hf, Ba, Cs, Tb, Sc, Rb, Fe, Zn, Ta, Co) have been determined by instrumental
neutron activation analysis in GSJ/AIST carbonate reference samples, JCp-1 (Coral) and JCt-1 (Giant Clam), together with JLk-1
(Lake Sediment), JDo-1 (Dolomite) and JLs-1 (Limestone) reference samples. 相似文献
9.
Determination of boron in water samples by chemical prompt gamma neutron activation analysis 总被引:1,自引:0,他引:1
P. S. Ramanjaneyulu Y. S. Sayi T. Newton Nathaniel A. V. R. Reddy K. L. Ramakumar 《Journal of Radioanalytical and Nuclear Chemistry》2007,273(2):411-414
Boron concentration has been determined in groundwater samples, collected from Khuchch, Gujarat, India, by prompt gamma neutron
activation analysis (PGNAA) after selective separation and pre-concentration by solvent extraction with 10% 2-ethyl hexane
1,3-diol in CHCl3. Solvent extraction separation helped to eliminate the interfering elements in PGNAA determination of boron. The sensitivity
of PGNAA is found to be 18.83 cps/mg B based on the slope of a calibration plot obtained by carrying out measurements on synthetic
boric acid samples containing boron in the range of 30–150 μg. Detection limit of the method is 0.2 μg/g counted for 35,000
seconds at a sample size of 15 gram. The precision (relative standard deviation at 1σ level) and accuracy of the method is
5%. The analytical results of the present method agreed well with well-established spectrophotometric determination of boron
as boron-curcumin complex and inductively coupled plasma atomic emission spectroscopy (ICP-AES). 相似文献
10.
Nickel sulfide (NiS) fire assay was used for the pre-concentration of Ir and Au in rock samples. The beads obtained after
fire assay were irradiated directly with neutrons to determine Ir and Au. To suppress the reaction of 58Ni(n,p)58Co, the fire assay was carried out by using a small amount of Ni (0.0625 g) and the NiS bead samples were irradiated by neutrons
with high Cd ratios. Analytical results of Ir and Au for rock samples were close to literature values, confirming that our
procedure of INAA with pre-concentration can be applied to rock samples for the determination of ppb to sub-ppb level of Ir
and Au. 相似文献
11.
Taiwan monazite is a unique mineral obtained from the heavy sand found in the river floor of Tzuo-suei river and En-suei river. Both rivers are flowing parallel with separated narrow area into the sea at southwestern coast of Taiwan. The characteristic of monazite is that it contains considerable rare earth elements (REEs). REEs are considered very useful elements in the local industries and scientific researches such as ceramic, semiconductors, and glass optics. In this study, chemical neutron activation analysis (CNAA) was used to determine the contents of REEs in Taiwan monazite. A few milligram of monazite was digested in the microwave oven for 25 minutes with mixed acid (conc. HNO3 and HClO4). REEs were preconcentrated by hydrated magnesium oxide and CNAA was performed. 相似文献
12.
F. Van den Bergh F. Adams J. Hoste 《Journal of Radioanalytical and Nuclear Chemistry》1970,4(2):347-353
Neutron activation analysis was applied to the determination of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Yb, Lu and Th in rare-earth
concentrates resulting from minerals. High-resolution gamma-ray spectrometry with a Ge(Li) detector was used for the non-destructive
determination, and a single comparator method using Co as flux monitor was applied. 相似文献
13.
M. Ebihara H. Ozaki F. Kato H. Nakahara 《Journal of Radioanalytical and Nuclear Chemistry》1997,216(1):107-112
Chlorine, bromine and iodine (hereafter, halogens) were detemined for rock samples by radiochemical neutron activation analysis. The powdered samples and reference standards prepared from chemical reagents were simultaneously irradiated for 10 to 30 minutes with or without a cadmium filter in a TRIGA-II reactor at the Institute for Atomic Energy, Rikkyo University. The samples were subjected to radiochemical procedures of halogens immediately after the irradiation. Iodine was firstly precipitated as PdI2, and chlorine and bromine were successively precipitated as Ag-halides at the same time. In this study, geological standard rocks, sedimentary rocks and meteorites were analyzed for trace halogens. In some Antarctic meteorites, iodine contents were observed to be anomalously high. Chlorine contents also are somewhat high. The overabundance of iodine and chlorine must be caused by terrestrial contamination on the Antarctica. 相似文献
14.
K. S. Park N. B. Kim Y. S. Kim K. Y. Lee 《Journal of Radioanalytical and Nuclear Chemistry》1987,114(2):359-365
The relative ans single comparator methods have been applied to determine 7 rare-earth elements and U, Th in Korean Monazites by 14.5 MeV neutron activation analysis. The (n, 2n) nuclear reactions are used for all elements except La, for which (n, p) reaction is used. Al is used as a flux monitor for the relative method and as a singlle comparator for the single comparator method. The analytical results obtained by the two methods agree well within 3% deviation except for Sm and Gd. These results are also compared with the result obtained by a single comparator method using reactor neutron. 相似文献
15.
Applying rapid radiochemical separation of iodine coupled with epithermal neutron activation, we reliably determined trace amounts /6–95 ng/ of iodine in rock samples such as sedimentary rocks and chondritic meteorites. Our data on meteorites are in good agreement with literature values, but for sedimentary rocks the present data were systematically lower than the literature values. Based on the data from duplicate analyses of some sedimentary rocks and the results of tracer experiments employed parallel to the rock analyses, we concluded that the analytical results obtained in this work for sedimentary rocks were more reliable than the literature values. 相似文献
16.
K. R. Shah R. H. Filby W. A. Haller 《Journal of Radioanalytical and Nuclear Chemistry》1970,6(1):185-192
Using thermal neutron activation and a large-volume high-resolution Ge(Li) γ-ray spectrometer, the feasibility of the determination
of the concentrations of Na, S, Cl, K, Ca, V, Mn, Cu, Ga, and Br in crude oils has been demonstrated. This instrumental method,
which requires neither a chemical separation technique nor pre-concentration or post-concentration of trace elements by ashing,
eliminates many inherent errors associated with chemical determination. The method is sensitive, precise and suitable for
routine analysis. Fast neutron (n, p) and (n, α) reactions do not appreciably interfere and where necessary corrections may
be applied. Loss of volatile elements, e.g. chlorine and bromine, due to recoil during irradiation is negligible. 相似文献
17.
The concentration of inorganic elements in medicinal plants may be related to the concentration of active constituents. Instrumental
neutron activation analysis has been employed to determine the elements antimony, cesium, chlorine, cobalt, iron, manganese,
nickel, potassium, rubidium, selenium, sodium and zinc in different parts of Helleborus cyclophyllus BOISS. and in the soil
in which the plant was grown. It has been found that antimony has a selective accumulation in the rhizome of this plant where
the active constituents are located, as well as chlorine in petioles and leaves. 相似文献
18.
Rick L. Paul Elizabeth A. Mackey Rolf Zeisler Rabia O. Spatz Bryan E. Tomlin 《Journal of Radioanalytical and Nuclear Chemistry》2009,282(3):945-950
A combination of instrumental neutron activation analysis (INAA) and prompt gamma-ray activation analysis (PGAA) was used
to value assign 35 elements in SRM soil 2709a (San Joaquin Soil). INAA with counting of short-lived radioisotopes was used
for determination of Al, Au, Ca, Dy, K, Mg, Mn, Na, Ti, and V. Elements determined by INAA with counting of intermediate and
long-lived radioisotopes included As, Ba, Ce, Co, Cr, Cs, Eu, Fe, Hf, La, Lu, Nd, Rb, Sb, Sc, Sm, Sr, Ta, Tb, Yb, Zn, and
Zr. Thermal neutron PGAA was used for the determination of H, B, Si, K, Ti, Mn, Fe, Cd and Gd. Expanded uncertainties were
determined for all values reported. 相似文献
19.
A. Chatt H. S. Dang B. B. Fong C. K. Jayawickreme L. S. McDowell D. L. Pegg 《Journal of Radioanalytical and Nuclear Chemistry》1988,124(1):65-77
Neutron activation analysis (NAA) methods have been developed for the determination of major, minor and trace elements in duplicate diets and individual food items. These include a cyclic instrumental NAA (CINAA) method for measuring Se content through its short-lived nuclide77mSe; epithermal INAA (EINAA) for I and As; conventional INAA for Br, Ca, Cl, Co, Cr, Fe, K, Mg, Mn, Na, Rb, Sb, Sc, Sn and Zn; combination of EINAA and INAA for Al; radiochemical NAA (RNAA) for As, Au, Co, Cu, Fe, Hg, Mo, Sb, Se and Zn; and preconcentration NAA (PNAA) for U and Th. Accuracy of measurements have been evaluated by analyzing a number of biological and diet reference materials. Multielement concentrations of diets and foods have been measured by these methods. 相似文献
20.
K. R. Shah R. H. Filby W. A. Haller 《Journal of Radioanalytical and Nuclear Chemistry》1970,6(2):413-422
Instrumental neutron activation analysis (INAA) and Ge(Li) spectrometry have been used to determine Sc, Cr, Fe, Co, Ni, Zn,
As, Se, Sb, Eu, Au, Hg, and U in crude petroleum. The technique involves no chemical separations and no pre-concentration
of the samples by ashing is necessary, thus avoiding contamination or loss of volatile elements. The estimated detection limits
in ppb for the elements are Sc (0.1), Cr (0.16), Fe (400.0), Co (0.6), Ni (1.1), Zn (200.0), As (6.0), Se (23.0), Sb (1.0),
Eu (0.58), Au (0.11), Hg (4.3), U (1.5). Precision values ranged from 0.1% to 15% (relative standard deviation). Interferences
in the Co and Fe determinations due to fast neutron reactions (n, p) and (n, α) on Ni isotopes are small and are easily corrected.
Losses of As, Se, and Hg due to escape of volatile gases during irradiation are negligible 相似文献