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1.
Instrumental neutron activation analysis (INAA) and pseudocyclic INAA (PCINAA) have been used to determine the selenium content
of a variety of Canadian food items. Use of the 162-keV gamma ray of short-lived77mSe in INAA allowed relatively simple and rapid determinations and was suitable for many of the foods. PCINAA was found to
give lower detection limits and was used for the low-selenium food samples. Both internal and external quality assessments
were used to evaluate and assure the accuracy and precision of the methods developed. 相似文献
2.
Chen Chunying Zhang Peiqun Hou Xiaolin Chai Zhifang 《Biological trace element research》1999,(1):131-138
Selenium is an important and essential trace element to living systems. In the article, two methods of instrumental neutron
activation analysis and hydride generation-atomic fluorescence spectrometry were applied to determine Se in biological samples
and the accuracy was evaluated by several reference materials. The subcellular distribution of selenium in human liver samples,
which were obtained from normal subjects who had an accidental death, was investigated by differential centrifugation combined
with INAA. Selenium was mainly enriched in mitochondria, nuclei, and cytosol. Almost half of the total Se content existed
in nuclei as a result of the large amount in liver and the high Se concentration. Generally, the highest Se concentration
in the mitochondrial fractions of each liver sample suggested that Se had important functions in this liver component. 相似文献
3.
A rapid cyclic instrumental neutron activation analysis (CINAA) method has been used to determine the selenium content of
27 duplicate diet samples from each of the 27 districts surrounding Pinhel, Portugal. The accuracy and precision of the CINAA
method have been evaluated by analyzing certified reference materials and observed to be within ±5–10% for samples containing
at least 40 ppb of selenium. The detection limit has been found to vary between 26–42 ppb selenium depending on the sample
composition. The average daily dietary intake has been calculated as 37 μg of selenium per day. 相似文献
4.
Zhong Honghai Tan Minjia Fu Yuliang Huang Jingqing Tang Zhenfang 《Biological trace element research》1999,(1):569-574
In this article, the low-temperature freeze-drying pretreated technique and instrumental neutron activation analysis were
used to determine 29 trace elements in samples of human uterine cancer tissue. The content of these trace elements in uterine
cancer tissue was compared with that in cervicitis tissue and in healthy tissue, respectively. Preliminary results indicated
that significant differences in contents of Au, I, and Se were observed in these tissues. 相似文献
5.
Epithermal instrumental neutron activation analysis (EINAA) has been used to determine the iodine content of many individual
food materials that constitute the typical Libyan diet. The selected samples include different varieties of local and imported
foods such as wheat and barley products, rice, bread, legumes such as chick peas and lentil, table salt, and commonly used
spices, including thyme and fenugreek. Both conventional and anticoincidence γ-ray spectrometry techniques have been employed.
Epithermal INAA in conjunction with anticoincidence counting has been found to provide the most reliable results. For quality
control purposes, a number of NIST biological reference materials were analyzed. The range of daily dietary intake has been
calculated as 100–180 μg of iodine per day, which is within the recommended range. Bread was identified as a significant source
of iodine in the Libyan diet, as it contributed 99 μg/d. 相似文献
6.
Masuzawa Toshiyuki Suzuki Teruyuki Seki Kayoko Kosugi Tsuyoshi Hibi Yuriko Yamamoto Mineko Takada Jitsuya Matsushita Rokuji Yanada Mitsuru 《Biological trace element research》1999,(1):331-342
Phytoplankton samples were collected during spring bloom of diatoms from three coastal areas of Japan using a NORPAC P-25
net (25-Μm opening) with a NGG52 prenet (335-Μm opening), and 25 major and trace elements have been analyzed by INAA. Concentration
ranges of analyzed phytoplankton samples are much wider than the concentration ranges compiled by Bowen (1979) except for
As, and data of marine phytoplankton samples for Br, Sb, Hf, Sc, La, Ce, Sm, and Eu were not included in the compilation.
The 25 analyzed elements have been categorized into three groups: elements showing positive correlation with Br, positive
correlation with Al, and no positive correlation with Br or Al. The marine phytoplankton samples have been plotted on a Masuzawa-Koyama-Terazaki
(MKT) plot and it proved that the MKT plot is applicable to marine phytoplankton samples. 相似文献
7.
Antimony was preconcentrated from natural waters on thionalide-loaded acrylic polymer (Bio-Beads SM-7) from 0.5 m HCl solution.
Prior to the preconcentration, Sb(V) was reduced to Sb(III) with potassium iodide. The antimony retained on the resin was
determined by neutron activation and γ-spectrometric measurement of122Sb (564 keV). The lower limit of detection was 0.023 μg/L for a 100-mL sample. 相似文献
8.
Panayi Antonia E. Spyrou Nicholas M. Ubertalli Livio C. White Mark A. Part Peter 《Biological trace element research》1999,(1):529-540
Methods have been developed for the analyses of trace metals in various areas of porcine brains, (temporal, parietal, frontal
cortex, both right and left hemispheres). Determinations were carried out using inductively coupled plasma-mass spectrometry
(ICP-MS) and electrothermal atomic absorption spectrometry (ETAAS). The elements investigated were Li, Mn, Cu, Zn, Cd, Hg,
and Pb by ICP-MS and Cu, Cd, and Mn by ETAAS. For determination by ICP-MS, a method of standard additions calibration coupled
with internal standards was used, and for ETAAS, standard additions calibrations were prepared. The accuracy of all methods
was determined using NIST and IAEA certified reference material.
A small number of pig brains were analyzed by instrumental neutron activation analysis for Cr, Co, Cs, Fe, Rb, Se, Sc, Sb,
and Zn using the comparator method of analysis. Four separate NIST standard reference materials have been used to examine
the validity of the comparator method. 相似文献
9.
The central nervous system (CNS) should be especially sensitive to disturbances in trace element concentrations because of
its high metabolic rate and low capacity for regeneration. Comparatively few studies have been made on trace elements in the
CNS, which prompted us to begin a study of trace elements in four different brain lobes of the CNS, as well as in the spinal
cord. Samples were obtained at autopsy and handled carefully in order to avoid contamination. They were freeze-dried and sealed
in quartz tubes that were irradiated in a nuclear reactor. A simple chemical separation into six fractions was performed.
The gamma spectra for these fractions was registered using a Ge(Li) detector and a computerized multichannel analyzer. Results
for the following elements were obtained: Ca, Cd, Co, Cr, Cs, Cu, Fe, Rb, Se, and Zn, as well as for Na and K (not reported).
Other elements were also detected in some samples. Using this technique, brain samples from ten patients with Alzheimer’s
disease and ten control cases were examined. 相似文献
10.
Three models were used to determine the daily dietary Selenium intake in Slovakia. The Selenium content of food produced and
consumed in the Slovak Republic was used to estimate and calculate the daily Selenium intake based on food consumption data
per capita and seven days, (24 h) eating protocol models. In a duplicate portion model, Selenium was analyzed in a whole day
hospital diet during an eight-day period. According to these models the daily dietary Selenium intake was 38.2 μg; 43.3 ±6.5
μg for men and 32.6 ±6.6 μg for women; 27.1 ±7.8 μg for normal and 32.3 ±4.8 μg for nourishing hospital diets. The main contributors
of Selenium to daily intake were the following: eggs, pork, and poultry. The obtained results indicate that the daily dietary
intake of Selenium of the Slovak people is below the recommended values. 相似文献
11.
Naoki Saitoh Takao Suzuki Tohru Kishi Atsuo Iida Yohichi Gohshi 《Biological trace element research》1987,12(1):211-220
Human scalp hair and some kinds of vegetable and animal fibers were analyzed by means of the SR excited X-ray fluorescence
method (SRXFA) and the neutron activation method (NAA). Human hair samples collected from five males and five females were
washed by the IAEA method prior to analysis. In the SRXFA analysis, samples were excited by monochromated X-rays. Fluorescence
X-rays were measured by an Si(Li) detector. The elements detected in all hair samples were S, Ca, Cu, Fe, Zn, Br, and Sr.
The elements K, Ti, Cr, Mn, Ni, Se, Hg, and Pb were also detected in several samples. After SRXFA analysis these same samples
were analyzed by the NAA method. Elements such as Cu, Zn, and Br were detected by both methods, and their relative concentrations
show a good agreement of variation between individuals. However, Pb was only detected by SRXFA, and Na, Au, and Sb were only
detected by NAA. Therefore, these two methods are complementary to each other for trace element analysis. 相似文献
12.
The instrumental neutron activation analysis method was used for the determination of trace elements in rib bone samples taken
from autopsies of accident victims. The elements Br, Ca, Cl, Cr, Fe, Mg, Mn, Na, P, Sr, Rb, and Zn were determined in cortical
tissues by using short and long irradiations with thermal neutron flux of the IEA-R1m nuclear reactor. The reference materials
NIST SRM 1400 Bone Ash and NIST SRM 1486 Bone Meal were also analyzed in order to evaluate the precision and the accuracy
of the results. It was verified that lyophilization is the most convenient process for drying bone samples because it does
not cause any element losses. Comparisons were made between the results obtained for rib samples and the literature values
as well as between the results obtained for different ribs from a single individual and for bones from different individuals. 相似文献
13.
Tomoko M. Nakanishi Jun Takahashi Hisayoshi Yagi 《Biological trace element research》1997,60(3):163-174
Seven representative wood species constituting Caatinger forest in north-east Brazil were chosen to analyze La, Ce, Sm, Eu,
Yb, Sc, and Al by instrumental neutron activation analysis (INAA). Soil profiles were prepared where the trees were downed.
Then soil and root samples from each horizontal soil layer, as well as the upper part of the wood, ground-level bark, and
the bark at 1 m above were collected. In woods, the rare earth element (REE) was found to be mainly accumulated in root, which
concentration was in the same order as that of soil. In all samples, concentration of La and Ce were found to be about ten
times higher than those of the other REEs. The REE accumulation became higher, in both root and soil, in the order of La,
Ce, and Sm. The partition rate of La and Eu was higher from soil to root, whereas Ce tended to be concentrated from root to
bark. In the case of bark, there was no tendency of specific REE accumulating from ground level to the upper part. The correlation
of La concentration to the other REE was higher in root than that of corresponding soil. Roots also showed higher correlation
of REE to Al and Sc than that of soil or bark. 相似文献
14.
Ryde S. J. S. Morgan W. D. Compston J. Evans C. J. Sivyer A. Dutton J. 《Biological trace element research》1990,(1):429-437
A clinical neutron activation instrument has been developed for in vivo elemental analysis. Utilizing the prompt-capture gamma
ray technique, simultaneous total body (TB) measurements of primarily Ca, but also Cl, N, C, and H are routinely performed.
This paper describes a technique for the measurement of TBCa (g) that relies on the use of TBCl as an internal standard. The
method has been tested with four anthropomorphic phantoms covering a range of body habitus. The mean discrepancy between the
measured and known Ca contents was 3.6%. The technique has been applied to two patient groups, and encouraging results were
obtained. 相似文献
15.
Preliminary study on the determination of selenium compounds in some selenium-accumulating mushrooms
Slejkovec Z van Elteren JT Woroniecka UD Kroon KJ Falnoga I Byrne AR 《Biological trace element research》2000,75(1-3):139-155
Using various chromatographic techniques (size exclusion, anion exchange, and cation exchange) combined with several detectors
(neutron activation analysis and atomic fluorescence spectrometry), an attempt was made to characterize selenium compounds
in some edible, selenium-accumulating mushrooms (Albatrellus pes-caprae and Boletus edulis).
The mushrooms contained mostly low-molecular-weight (6 kDa) selenium compounds. After proteolysis, only a small fraction of
the extractable selenium could be identified as selenite (3.0–9.2%, Albatrellus pes-caprae), selenocystine (minor, Albatrellus pes-caprae; 7.5%, Boletus edulis), or selenomethionine (1.0%, Boletus edulis), leaving the form of the bulk still to be elucidated. 相似文献
16.
Edward J. B. Beeley P. A. Bennett L. G. I. Poland J. S. 《Biological trace element research》1990,(1):53-61
A microcomputer-controlled irradiation and measurement system and a microprocessor-controlled sample changer have been installed
at the SLOWPOKE-2 Facility at the Royal Military College of Canada (RMC). These systems can provide the gamut of instrumental
neutron activation analysis (INAA) techniques for the analyst. Custom software has been created for system control, data acquisition,
and off-line spectral analysis using programs that incorporate Gaussian peak-fitting methods of analysis. The design and use
of the equipment is discussed, and the performance is illustrated with results obtained from the analysis of marine sediment
and biological reference materials. 相似文献
17.
The pre-irradiation combustion (PC) of samples to liberate iodine, followed by trapping the iodine on charcoal and quantifying
the element by neutron activation analysis (NAA), has been used at the National Institute of Standards and Technology for
the determination of iodine in biological materials. The applicability of this technique to numerous environmental and dietary
matrices is illustrated by analysis of a range of certified reference materials (CRMs) and a powdered grass material that
was prepared as an in-house reference material (RM). Because of the combustion step involved, samples with low or no fat content
(e.g., cereal products, selected botanical specimens, and nonfat milk powder) and inorganic materials (e.g., coal fly ash
and dried sediments) are more suited for analysis by this method. In general, the results for several types of samples obtained
by this method agreed with those obtained by a second radiochemical (R) NAA, as well as by a third method using inductively
coupled plasma mass spectrometry (ICP-MS). PC-NAA is a useful technique for determining iodine in biological and environmental
samples, especially for verification of iodine results obtained from other methods. 相似文献
18.
Samples of residual sands were analyzed for precious metals content. These samples were collected from one of the largest
silver mines in the world with the purpose of determining the existence and quantities of precious metals. The collected samples
were approximately 5 kg, taken from different sites within the deposit grounds. Each sample was passed through a sieve in
order to select only the smallest particles and about 100 g per sample were obtained. Twenty samples were prepared that produced
thin foils from which the samples were cut in the shape of disks.
The neutron activation analysis method (NAA) was used in this work, using a nuclear reactor (Triga Mark III) as a neutron
source and a high-purity germanium detector as spectrometer. The results from the analysis of this study are satisfactory;
the main precious metals found were Au, Ru, Os, and Ir. A commercial study is necessary to determine if the exploitation of
these sands is financially feasible. 相似文献
19.
Gallorini M. Rizzio E. Birattari C. Bonardi M. Groppi And F. 《Biological trace element research》1999,(1):209-222
The concentrations (ng/m3) of more than 30 trace elements have been determined in the total air particulate matter and in the sizesegregated fractions
collected in urban, industrialized, and rural residential areas in northern Italy by means of a multistage inertial impactor
with the PM10 inlet. All measurements have been carried out by instrumental neutron activation analysis, except for Pb and
Cd, which have been determined by electrothermal atomic absorption spectroscopy. Analytical quality assurance procedures have
been developed with special regard to blanks, reagents, and sampling. Total concentrations and the granulometric distribution
found in the different locations are reported and compared. 相似文献
20.
Although knowledge of the total concentrations of trace metals in the environment and living organisms is still the essential
starting point for any toxicological evaluation, it is, however, not sufficient to explain the mechanisms responsible for
retention and toxic effect of trace metals. Differentiation between their chemical and biochemical forms is necessary. The
need to resolve the total concentration of trace metals into single chemical species poses great experimental difficulties
and imposes the use of very sensitive analytical techniques for trace metal determinations after specific preseparation procedures
of the different chemical species.
Thus, once the chemical or biochemical metal species have been selectively isolated, the speciation becomes merely an analytical
problem, which requires high sensitivity and accuracy, as well as the evaluation of matrix effects, blanks, contamination,
loss, and sampling.
This paper describes the use of nuclear and radiochemical techniques related to chemical and biochemical speciation problems
at the Joint Research Centre, Ispra, with carrier-free radiotracers and radiochemical neutron activation analysis. 相似文献