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1.
An INAA technique employing beta spectrometry was developed for the determination of phosphorus in polymers. The (n,γ) reaction
on phosphorus produces32P, half-life 14.3 days, a pure beta emitter with end-point energy 1.71 MeV. Polymer samples in the form of powders, films
and pellets are irradiated and then counted with a plastic scintillator. The beta spectrum is corrected for interferences
(especially Sb, Zn and Br which are quantified by gamma spectrometry) and for energy loss in the thick sample. Samples must
also be analyzed for S and Cl which cause nuclear interferences. With an irradiation time of 4 hours at a neutron flux of
5·1011 n·cm−2
s
−1, decay time 10 days and counting time 10 minutes, the sensitivity is 520 counts/μg phosphorus and the detection limit is
typically 2μg/g. 相似文献
2.
H. Zhang Z. F. Chai W. Y. Qing H. C. Chen 《Journal of Radioanalytical and Nuclear Chemistry》2009,281(1):23-26
Cyclic neutron activation analysis method was conducted for determination of Se in food samples. High accuracy and good precision
were proved by analyzing certified reference materials (CRMs) of chicken (GBW10018), rice (GBW10010) and cabbage (GBW10014).
The detection limits for the three CRMs reached 0.16, 0.66 and 1.2 ng after 6 cycles at the 161.9 keV γ-peak from 77mSe, under a neutron flux of 9.0 × 1011 n cm−2 s−1 and the conditions of 30 s irradiation, 2 s decay, 30 s counting and 2 s waiting, significantly lower than those of conventional
neutron activation analysis without any cycles, which were 0.94, 3.6 and 4.3 ng, respectively. 相似文献
3.
Stacey D. Haskins David G. Kelly Ron D. Weir 《Journal of Radioanalytical and Nuclear Chemistry》2011,287(2):471-478
Instrumental neutron activation analysis (INAA) was used to determine trace elemental contamination in bird feathers. Primary
feathers from twelve mallard (Anas platyrhynchos) ducks, migrating through the Thousand Islands region of Ontario, Canada, were analyzed for selenium, mercury, chromium,
arsenic and antimony. Certified reference materials were used to assess the quality of the analytical procedure. Quantification
of chemical elements was performed using Ortec Gamma Vision software. Five chemical elements were quantified, with corresponding
analytical uncertainties of less than 20%. Results indicated the presence of As (max = 0.13 mg kg−1), Cr (max = 2.6 mg kg−1), Hg (max = 7.7 mg kg−1), Sb (max = 0.31 mg kg−1) and Se (max = 1.31 mg kg−1). To assess the validity of using INAA as a quantitative analytical technique for feather samples, two standard reference
materials were examined and mercury results were compared to those obtained from both direct mercury analysis (DMA) and cold
vapour atomic absorption spectroscopy (CVAAS). Several CVAAS results differed significantly from the INAA results; in many
instances CVAAS appeared to under-report when compared to INAA, with relative percent difference values as high as 126%. Conversely,
results obtained using DMA compared favourably with INAA. For all samples, RPD values were within 30%. This is the first study
to use INAA to examine feather contamination in Canadian migratory waterfowl and the first to corroborate INAA feather results
by comparing them to those obtained using CVAAS and DMA. 相似文献
4.
Mohammad A. Hannan Jesus Tanguma 《Journal of Radioanalytical and Nuclear Chemistry》2012,291(3):745-751
Neutron Activation Analysis (NAA) was applied to determine trace and major elements in Mission–Progresso (Texas) soils. The
Rio Grande river runs along the USA—Mexico border. The soil samples were collected at Mission and Progresso areas of the Rio
Grande riverbank in the USA side. Soils were analyzed for the presence of toxic effluents due to human activities that might
affect agricultural products and health because one of the possible paths of intoxication is the agricultural product consumption.
Dried, sieved, and blended soil samples (~1.5 g) were irradiated at the UT Austin TRIGA reactor at a thermal neutron flux
of 1 × 1012 n cm−2s−1 and epithermal neutron flux of 1 × 1011 n cm−2s−1. Different irradiations, decay, and counting times were combined to determine concentration and detection limits of 21 elements
which represent four areas in Mission–Progresso (Texas) with the aim to achieve a consistent characterization. NIST certified
reference materials were used in relative analysis and also to determine the accuracy and reproducibility values. The neutron
flux was monitored using sulfur flux monitor wires. Normal and Compton suppression gamma ray spectrometers were used to detect
different gamma ray energy peaks and this Compton system greatly reduces the background. Concentrations are evaluated in per
cent and parts per million and errors are within acceptable levels and these values are compared with values reported in literatures
from other countries. The results do not show significant contaminations neither from the Rio Grande river nor from nearby
industries. 相似文献
5.
6.
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
7.
Geraldo Capannesi Alberto Rosada Maurizio Manigrasso Pasquale Avino 《Journal of Radioanalytical and Nuclear Chemistry》2012,291(1):163-168
In geochemistry, the distribution of the Rare Earth Elements (REEs) in earth crust and mantle allows to understand geochemical
cycles and origin and age of igneous rocks. In this article REEs (Ce, Dy, Eu, La, Nd, Sm, Tb, and Yb), Th and U in ores of
the North-Latium (Bracciano area, Ceriti Mt., Fate Mt., Sabatini Mt., Vulsini Mt., Acqua Rossa basin), have been investigated
for evaluating the extraction feasibility for industrial applications. 107 samples were irradiated in the rotating rack of
the TRIGA Mark II reactor of the R.C. Casaccia (ENEA) at neutron flux of 2.6 × 1012
n × cm−2 × s−1 for 12 h together with primary and secondary standards. The gamma spectrometry measurements were performed after 8 h, 3 and
30 days of decay by means of HPGe detector (FWHM 1.75 keV at 1332.5 keV, peak/Compton ratio 55.1, relative efficiency of 22%)
connected to a multi-channel analyzer. The total REE mean content is 105 μg g−1, ranging widely between 2.23 and 410.5 μg g−1 (average coefficient of variation 112%). A similar behavior is found for Th and U: their average levels are 13.5 and 6.0 μg g−1, respectively. A quite good correlation between REEs and Th (and U) is found for Ceriti Mt. (r
2 > 0.8) whereas for the other areas the correlation is <0.7. The results obtained evidence the low U content in the investigated
locations. 相似文献
8.
Biological materials containing trace amounts of mercury and selenium were examined using neutron activation analysis. They
were analyzed using Compton suppression and γ–γ coincidence counting. The 279 keV photopeak of activated mercury (203Hg) was analyzed in order to observe the mercury content in these samples. Selenium, an element found in many biological samples,
interferes with the analysis of 203Hg when activated (75Se). Because the selenium interference comes from a cascading emission, Compton suppression was utilized to reduce this interference.
In order to fully characterize the selenium content in the samples, γ–γ coincidence was used which reduced the background
and eliminated bremsstrahlung interference produced from neutron activated phosphorous through the 31P(n, γ)32P reaction which is a pure beta emitter. As a result, we determined the mercury and selenium concentrations in three standard
reference materials, which contain varying ratios of mercury to selenium concentrations. This study also showed that these
types of concentrations can be determined from small (<500 mg) sample masses. Further work needs to be done on wet samples
that require dehydration, as mercury can be lost through this process. 相似文献
9.
S. Ohde K. Tanaka A. Snidvongs H. Matsue 《Journal of Radioanalytical and Nuclear Chemistry》2011,289(2):401-406
A systematic and non-destructive technique is proposed for the determination of boron in coral samples by neutron-induced
prompt γ-ray analysis (PGA) using a thermal neutron guide beam of the JRR-3M reactor. About 50–150 mg samples in sealed FEP
film were irradiated and measured for 5000 s in the PGA system at a neutron flux of 2.4 × 107 n cm−2 s−1. In order to determine B content in coral skeletons, the Doppler-broadened γ-ray peak of 478 keV (10B) was used together with the correction of interference from the Na-peak of 472 keV. The analytical precision was ~3% for
the JCp-1 coral standard. The data (n = 56) obtained by the present method showed a range of B content from 40.7 to 76.9 ppm which is similar to reported values.
Boron in corals showed the highest levels in Rukan-sho (Okinawa) with an average B content of 62.5 ppm, whereas corals collected
from Mizugama (Okinawa), Cebu (the Philippines) and Khang Khao (Thailand) exhibited B contents of 56.5, 53.0 and 45.7 ppm,
respectively. The uptake of boron by living corals may be influenced by seawater pH related to higher seawater B(OH)4−. In this paper we discuss factors controlling the B levels in corals. 相似文献
10.
A. A. M. Sharif H. Ghafourian A. Ahmadiniar S. Waqif Husain M. Saber-Tehrani H. Ghods 《Journal of Radioanalytical and Nuclear Chemistry》2004,261(2):473-477
Aluminum levels of serum and red blood cell (RBC) were determined by instrumental neutron activation analysis (INAA) in 15
patients undergoing long-term haemodialysis. In the sample, aluminum was bombarded with thermal neutrons due to 27Al(n,γ)28Al and was determined by measuring 1779 keV gamma-ray of 28Al (T
1/2 = 2.24 min) with a HPGe detector. Phosphorus, causing an important interference by the fast neutron reaction, 31P(n,α)28Al, was determined by the photometric method to correct the net-area under the 28Al gamma-peak. The one-sample Kolmogorov-Smirnov test was used to control the normality distribution of the aluminum levels
in serum and RBC. The results obtained were found to be in agreement with the serum aluminum determination performed by electrothermal
atomic absorption spectrophotometry. The statistical results show a correlation between the aluminum levels of serum and RBC.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
11.
I. Kawabe T. Tanaka V. Ekambaram A. M. Davis L. Grossman 《Journal of Radioanalytical and Nuclear Chemistry》1986,102(1):227-238
Second-order neutron activation becomes a serious interference in NAA determinations of REE in submilligram samples of meteoritic and terrestrial materials when neutron fluences reach levels of 1020 n·cm–2 or more. The Dy-interference to Ho determination and the Eu-interference to Gd determination are quite, large. We discuss the importance of second-order activation interferences in REE determinations, and present an experimental method to correct the Dy-interference to Ho determination by INAA. Ho concentrations in splits of less than 0.2 mg of BCR-1 and SP can be accurately determined by INAA with a neutron fluence of 2·1020 n·cm–2 in spite of large Dy interferences of up to 200%. It is necessary for NAA determinations of REE with high neutron fluences that each REE standard be separated from its neighboring REE, in order to correct the second-order activation interferences experimentally. 相似文献
12.
S. Pavelka M. Vobecký A. Babický 《Journal of Radioanalytical and Nuclear Chemistry》2008,278(3):575-579
The study describes a mode of non-destructive simultaneous determination of bromine and iodine concentrations, by reactor
instrumental neutron activation analysis (INAA) in the regime of short-term activation. Under the conditions of 1-minute activation
in the neutron flux of 8.0·1013 n·cm−2·s−1, it was possible to determine reliably as little as 5·10−8 g bromine and about 10−7 g iodine in matrices of a given type and of the mass of about 5 mg dry weight. We applied this method for the determination
of Br and I concentrations in the whole rat thyroid gland as well as for the halogen speciation in fractions separated from
this organ. 相似文献
13.
Natalia García-Otero Carmen Teijeiro-Valiño Jacobo Otero-Romaní Elena Peña-Vázquez Antonio Moreda-Piñeiro Pilar Bermejo-Barrera 《Analytical and bioanalytical chemistry》2009,395(4):1107-1115
Nickel(II) and lead(II) ionic imprinted 8-hydroxyquinoline polymers were synthesized by a precipitation polymerization technique
and were used as selective solid phase extraction supports for the determination of nickel and lead in seawater by flow injection
solid phase extraction on-line inductively coupled plasma-optical emission spectrometry. An optimum loading flow rate of 2.25 mL min−1 for 2 min and an elution flow rate of 2.25 mL min−1 for 1 min gave an enrichment factor of 15 for nickel. However, a low dynamic capacity and/or rate for adsorption and desorption
was found for lead ionic imprinted polymer and a flow rate of 3.00 mL min−1 for 4-min loading and a flow rate of 2.25 mL min−1 for 1-min elution gave a enrichment factor of 5. The limit of detection was 0.33 μg L−1 for nickel and 1.88 μg L−1 for lead, with a precision (n = 11) of 8% (2.37 μg Ni L−1) for nickel and 11% (8.38 μg Pb L−1) for lead. Accuracy was also assessed by analyzing SLEW-3 (estuarine water) and TM-24 (lake water) certified reference materials,
and the values determined were in good agreement with the certified concentrations. 相似文献
14.
D. G. Kelly K. M. Mattson K. S. Nielsen R. D. Weir S. D. White 《Journal of Radioanalytical and Nuclear Chemistry》2012,291(1):89-94
The analysis of antimony in soil is an important component in the assessment of environmental risk associated with the discharge
of munitions at small arms ranges. Proficiency testing samples associated with accreditation to the ISO 17025 standard have
been examined for their antimony content using Instrument Neutron Activation Analysis (INAA) and using microwave assisted
in situ hydrofluoric acid or nitric acid digestion, or nitrate ashing, followed by ICP-MS analysis. Data are compared with
the proficiency testing criteria associated with accreditation and with consensus data. All three techniques afford data which
are consistent with accredited analyses. However, the antimony concentrations obtained are method dependant, and generally
as follows; INAA > in situ HF > nitrate ashing > nitric acid. In situ HF data and nitrate ashing data are systematically higher
and lower than consensus values, respectively, but within the acceptable accreditation range. INAA is the only technique which
affords a concentration for antimony in the certified reference material PACS-2 (10.0 ± 0.1 μg g−1) which is not statistically different from its certified value (11.3 ± 1.3 μg g−1). 相似文献
15.
Ho Manh Dung Menno Blaauw Daniel Beasley Maria Do Carmo Freitas 《Journal of Radioanalytical and Nuclear Chemistry》2012,291(2):485-492
The k
0-based cyclic neutron activation analysis (k
0-CNAA) technique has been studied to explore the applicability at the Portuguese research reactor (RPI). In particular, for
the determination of elements which form short-lived radionuclides, particularly fluorine (20F, 11.16 s half-life) and selenium (77mSe, 17.36 s half-life) in polymer, biological and environmental samples. The detection limits obtained for F and Se were about
50 and 0.01 mg kg−1, respectively, in the investigated materials. The timing parameters for the procedure were 10 to 20 s for irradiation, 5 s
decay, 10 to 20 s counting, 5 s waiting and performed with eight cycles. The k
0-IAEA program was modified to use millisecond time resolution for irradiation, decay and counting times as needed for interpreting
k
0-CNAA data in terms of concentration, accuracy and detection limit. The quality control of the procedure was performed by
preparing a standard solution containing fluorine with different contents as well as using the certified reference materials
containing selenium from which the bias between the results and the certified values were within 15% for most elements at
the investigated content ranges. The analytical results for several other elements producing short-lived or detectable radionuclides,
e.g., Al, Ca, Cl, Cu, Dy, I, Mg, Mn, Ti, and V were also obtained by the k
0-CNAA procedure with accuracy within 12%. 相似文献
16.
Autopsy of 29-year old woman suspicious of committing suicide by the ingestion of As2O3 yielded contradictory findings. All pathological findings as well as clinical symptoms suggested acute poisoning, while a
highly elevated As level of 26.4 μg g−1 in her hair collected at the autopsy, which was determined with inductively coupled plasma mass spectrometry indicated chronic
poisoning. To elucidate this discrepancy, instrumental neutron activation analysis (INAA) with proven accuracy was performed
of another set of sectioned hair samples. Levels of As found by INAA in the range of 0.16–0.26 μg g−1 excluded chronic poisoning, because the person died after approximately 14 h after the As2O3 ingestion. Two reasons for the discordant As results obtained by ICP-MS and INAA are considered: (1) accidental, non-removed
contamination of hair on the As2O3 ingestion; (2) erroneous performance of ICP-MS. 相似文献
17.
Microwave digestion and isotope dilution inductively coupled plasma mass spectrometry (ID-ICP-SFMS) has been applied to the
determination of Pb in rice flour. In order to achieve highly precise determination of low concentrations of Pb, the digestion
blank for Pb was reduced to 0.21 ng g−1 after optimization of the digestion conditions, in which 20 mL analysis solution was obtained after digestion of 0.5 g rice
flour. The observed value of Pb in a non-fat milk powder certified reference material (CRM), NIST SRM 1549, was 16.8 ± 0.8 ng
g−1 (mean ± expanded uncertainty, k = 2; n = 5), which agreed with the certified value of 19 ± 3 ng g−1 and indicated the effectiveness of the method. Analytical results for Pb in three brown rice flour CRMs, NIST SRM 1568a,
NIES CRM 10-a, and NIES CRM 10-b, were 7.32 ± 0.24 ng g−1 (n = 5), 1010 ± 10 ng g−1 (n = 5), and 1250 ± 20 ng g−1 (n = 5), respectively. The concentration of Pb in a candidate white rice flour reference material (RM) sample prepared by the
National Metrology Institute of Japan (NMIJ) was observed to be 4.36 ± 0.28 ng g−1 (n = 10 bottles).
Figure Digestion blank of Pb was carefully reduced to approximately 0.2 ng g-1 which permitted the highly precise determination of Pb at low ng g-1 level in foodstuff samples by ID-SFMS 相似文献
18.
Mohamed Soliman Nader M. A. Mohamed M. A. Gaheen E. A. Saad S. K. Yousef M. A. Sohsah 《Journal of Radioanalytical and Nuclear Chemistry》2011,287(2):629-634
The k
0-method of INAA standardization has been implemented using the irradiation facilities of the fast pneumatic rabbit and some
selected manually loaded irradiation positions, which designated for short and long irradiation, respectively, at Egypt second
research reactor. The neutron flux parameters (f and α) in each site have been determined using Zr–Au sets as neutron flux monitors. The reference materials coal NIST 1632c
and IAEA-Soil 7 were analyzed for data validation and good agreement between the experimental values and the certified values
was obtained. 相似文献
19.
Previous studies including the development of methods for the determination of carbon, nitrogen, and phosphorus in cattail
using cold neutron prompt gamma activation (CNPGAA) and thermal neutron prompt gamma activation analysis (TNPGAA); evaluation
of the precision and accuracy of these methods through the analysis of Standard Reference Materials (SRMs); and comparison
of the sensitivity of CNPGAA to TNPGAA have been done in the CNPGAA and TNPGAA facilities at the National Institute of Standards
and Technology (NIST). This paper integrates the findings from all of these prior studies and presents recommendations for
the application of CNPGAA and TNPGAA in environmental studies of plants based on synergistic considerations of the effects
of neutron energy, matrix factors such as chlorine content, Compton scattering, hydrogen content, sample thickness, and spectral
interferences from Cl on the determination of C, N, and P. This paper also provides a new approach that simulates a sensitivity
curve for an element of interest (S), which is a function of hydrogen content (X) and sample thickness (Y) as follows: S = aX + bY + c (where a, b, and c are constants). This approach has provided more accurate results from the analysis of SRMs than traditional methods and an
opportunity to use models to optimize experimental conditions. 相似文献
20.
Profile of selenium in soil and crops in seleniferous area of Punjab,India by neutron activation analysis 总被引:1,自引:0,他引:1
N. Sharma R. Prakash A. Srivastava U. S. Sadana R. Acharya N. T. Prakash A. V. R. Reddy 《Journal of Radioanalytical and Nuclear Chemistry》2009,281(1):59-62
In the Nawanshahr–Hoshiarpur region of Punjab, India, more than 1000 hectares of agricultural land is significantly affected
by high levels of selenium (Se). Studies were carried out to examine Se levels in soil and crops such as wheat grains, wheat
husk, rice, maize and mustard using neutron activation analysis. The Se concentrations in soil and crop products were found
to be ranging from 2.7 to 6.5 mg kg−1 and 13 to 670 mg kg−1, respectively, indicating significantly high selenium in these crop products. Two reference materials were analysed for Se
contents by INAA as controls. 相似文献