Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Neutron Activation Analysis”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources
PubMed2004

Prompt-gamma neutron activation analysis facility for in vivo body composition studies in small animals.

The design, calibration, dosimetry and performance evaluation of a prompt-gamma neutron activation analysis facility for in vivo body composition studies in small animals (i.e. rats or rabbits) is discussed. The system design was guided by Monte Carlo transport calculations using MCNP-4C code. A system was built and performance evaluation was made using a 185-GBq Pu-Be neutron source. Prompt-gamma rays produced by neutron capture reactions were detected by a combination of a NaI(Tl) scintillation and a HPGe semiconductor detectors. Nitrogen and chlorine were quantified by analysis of the 10.83-MeV and 6.11-MeV peaks, respectively. Appropriate corrections for the animal body size were determined. The facility described allows the in vivo determination of protein and extracellular space in sets of experimental animals.

Animals↗
PubMed1993

The development of a technique to measure bone aluminium content using neutron activation analysis.

The accumulation and toxicity of aluminium in patients with chronic renal failure is a well recognized hazard, and there is a need for a non-invasive technique to assess Al tissue load in these patients. The technique of in vivo neutron activation analysis, using a thermal neutron beam from a reactor, has been employed by previous workers, who measured Al in the hand with a detection limit of 0.4 mg for a dose equivalent of 20 mSv. However, the application of this technique is restricted by the very limited availability of nuclear reactors. We report the modification of an existing 252Cf-based instrument and construction of a shielded, high-efficiency counting system for the in vivo measurement of Al in the hand. Phantoms containing tissue-equivalent solutions of Ca, P, Na and Cl with various Al loadings were used for validation of the technique. The Al/Ca ratio in the hands of seven patients with renal failure was measured using a cyclic activation technique to compensate for the relatively low neutron output of the 252Cf source, and a detection limit of approximately 2.2 mg Al was achieved for a dose equivalent of 36 mSv. The results were compared with the Al content of iliac crest bone biopsy specimens measured using electrothermal atomic absorption spectrophotometry.

Adult↗
PubMedDate not supplied

An evaluation of the environmental implications of petroleum refinery emissions by multielemental neutron activation analysis of rumen fluid ash of buffaloes.

In order to study environmental pollution in and around a petroleum refinery complex, a multielemental instrumental neutron activation analysis (INAA) method was used to assay concentrations of As, Ba, Br, Cl, Co, Cr, Cs, Cu, Fe, Hg, La, Mn, Mo, K, Na, P, Sc, Rb, Se, Sr, W and Zn in the rumen fluid ash samples of buffaloes from the vicinity of the refinery. Corresponding samples from a control area 300 km away from the refinery were analysed. Standard Reference Materials, Bovine liver (SRM 1577a), Oyster tissue (SRM 1566a) and Animal bone (CRM H-5) were also analysed for quality control. Samples were irradiated with thermal neutrons at 10(12)-10(13) n cm-2 s-1 and counted by high-resolution gamma spectrometry. Mean elemental concentrations of As, Ba, Br, Cr, Hg and Fe were found to be enhanced, whereas those of Na, K, Cl, Cu, Mn and P were depleted in samples from the vicinity of the refinery complex compared to controls. The environmental implications of anomalous elemental concentrations are discussed.

Animals↗
PubMed2001

The potencial role of rare earths in the pathogenesis of interstitial lung disease: a case report of movie projectionist as investigated by neutron activation analysis.

A 60-year-old male subject who worked as a movie projectionist and who was exposed for 12 years to rare earths (RE) containing dusts from cored arc light carbon electrodes was investigated. Chest X-ray films and pulmonary function tests showed an interstitial lung disease, emphysema and a severe obstructive impairment with marked decrease of carbon monoxide diffusion capacity. The histological examination of a transbronchial biopsy confirmed the diffuse interstitial lung fibrosis. Neutron activation analysis (NAA) of the biopsy showed concentrations of cerium (Ce), lanthanum (La), neodimium (Nd), samarium (Sm), terbium (Tb) and ytterbium (Yb) which were high compared to the corresponding elements in the transbronchial biopsies of 5 unexposed subjects as a control group. Thorium (Th) (which is generally present as an impurity of the RE compounds) was also determined in order to estimate the radiation dose in the lung of the worker. On the basis of the clinical observations, of the analytical results by neutron activation analysis of RE and of the presence of Th in the transbronchial biopsy, as well as of the differential diagnosis, which tended to exclude other occupational or non-occupational lung diseases, a relation between the observed interstitial lung fibrosis and occupational exposure to RE is highly probable.

Biopsy↗
PubMed1984

[Reactor neutron activation analysis for aluminium in the presence of phosphorus and silicon. Contributions of 28Al activities from 31P(n, alpha) 28Al and 28Si(n, p) 28Al reactions].

Reactor neutron activation analysis for aluminium in samples containing phosphorus and silicon was studied. The experiments were performed by using neumatic tube of the Kyoto University Reactor (KUR). At first, the ratios of the 28Al activity produced from 27Al(n, gamma) 28Al reaction by thermal neutrons to that from 31P(n, alpha) 28Al reaction by fast neutrons, and to that from 28Si(n, p) 28Al reaction were measured by gamma-ray spectrometry. With a ratio of about 5 for the thermal to fast neutron flux of KUR, the ratio of the 28Al activity from aluminium to that from phosphorus was to be 812 +/- 7, and to that from silicon 282 +/- 3. Secondly, the contributions of 28Al activities from phosphorus and silicon and the determination limit of aluminium were calculated for various parameters, such as fast neutron flux, thermal to fast neutron flux ratio, amounts of phosphorus and silicon, etc. Thirdly, on the basis of these results, aluminium contents in spinal cords and brains of amyotrophic lateral sclerosis, Parkinsonism-dementia complex and control cases were determined.

Activation Analysis↗
PubMedDate not supplied

Inductively coupled atomic emission spectrometry and neutron activation analysis for the determination of element reference values in human lung tissue.

An investigation was undertaken in order to assess the performance of neutron activation analysis and inductively coupled plasma atomic emission spectrometry techniques for determining reference values for minor and trace elements in human lungs of urban subjects. Results show that in both instances experimental conditions must be carefully optimized to guarantee reliability of experimental data. Strict criteria for tissue sampling and pretreatment also had to be set. Provisional reference values for ca. 50 elements could thus be established.

Animals↗
PubMedDate not supplied

Instrumental neutron activation analysis of kidney stones.

Kidney stone samples of the types calcium oxalate, uric acid, and xanthine were analyzed for their elemental contents by neutron activation analysis to study both the elemental correlation and influence of element on stone precipitation processes. Elements, such as Al, Au, Br, Ca, Cl, Co, Cr, Fe, Hg, I, K, Mg, Na, Sb, Se, Sr, and Zn, were determined quantitatively. Calcium oxalate stones contained higher concentration of all the elements analyzed compared to uric acid or xanthine stones. The concentrations of Cl, Fe, K, Na, Sr, and Zn were relatively higher than Au, Co, Cr, and Sb. A positive correlation exists between Ca and Zn, whereas a negative correlation exists between Sr and Ca. Zinc may play an important role in the formation of calcium oxalate stone.

Calcium Oxalate↗
PubMed1990

Instrumental neutron activation analysis of gallstones.

Four kinds of gallstones from 40 patients have been analyzed for the presence of a total of 18 elements by instrumental neutron activation analysis. Of these elements, Ca, Mg, Fe, Co, Zn, Na, and Cl are found in the core of all types of stones. The differences in elemental composition of the various types of stones as well as the differences in the cross-sectional layers of stones are statistically evaluated.

Cholelithiasis↗
PubMed1999

Neutron activation analysis of Se in bovine plasma samples.

Elemental concentration of selenium in bovine plasma at parts-per-billion levels was determined using radiochemical neutron activation analysis (RNAA). This study was connected with the relation between the Enteque Seco, a toxic bovine calcinosis, and the Se status. The technique developed is based on the coprecipitation of Se with HgS. Good agreement with certified reference materials have been found. The values for the Se contents in normal bovine samples were in concordance with literature values.

Animals↗
PubMed1996

Occupational exposure amongst locomotive shed workers and welders using neutron activation analysis of scalp hair.

Elemental analysis of scalp hair of locomotive shed workers and industrial welders was used to study occupational exposure. Instrumental neutron activation analysis (INAA) was used for the determination of 17 elements, Ba, Br, Ca, Co, Cr, Cu, Fe, Hg, K, Mn, Na, P, Sb, Sc, Se, Th and Zn. Most elements show normal distribution at 95% confidence level. Further statistical significance was tested by correlation coefficient and regression coefficients (r2). Comparison of mean elemental contents of the subjects with controls shows a significant enhancement of Ca, Cr, Fe, Co, Na, Sc and Th, but declining trends for Br, Cu, P, Sb and Zn in locomotive shed workers. In the case of welders: Ba, Co, Cu, K, Mn, Sc and Sb show enhancement whereas Br, Cr, Hg, Se, Th and Zn exhibit depletion. Elemental contents have been correlated with possible sources of origin. Comparison of mean elemental data for the present population around Nagpur city matches well with the reported data for Bombay and Delhi. Comparative data from other countries are also presented.

Adult↗
PubMed1999

Heavy metals and rare earth elements source-sink in some Egyptian cigarettes as determined by neutron activation analysis.

Heavy metals and rare earth elements in two types of cigarettes were studied. The contents of trace elements were determined by using delayed neutron activation analysis. In the present study 11 elements have been detected in popular and fine brand cigarettes marketed in Egypt. Evaluation of these elements with their potential hazards for smokers is briefly discussed. The material balance (source and sink) for each element was determined. Also the ratio of element recovery to the total amount was assessed.

Antimony↗
PubMed1983

Total diet study: determination of iodine intake by neutron activation analysis.

Composite food samples from adult, infant, and toddler market baskets of the Food and Drug Administration's (FDA) Total Diet Study for Fiscal Year 1980 were analyzed for iodine by neutron activation analysis (NAA) at the FDA NAA laboratory at the National Bureau of Standards. The mean iodine content of the total diets was 412, 397, and 410 micrograms, per day for adult (2,900 kcal per day), infant, and toddler diets, respectively. These intakes correspond with 275%, 882%, and 586% of the adult, infant, and toddler Recommended Dietary Allowances, respectively. Dairy products and iodate-containing breads were major dietary sources of iodine. The iodine values for total diets reported here, determined by NAA, are from 11% to 15% higher than those determined by colorimetric analysis at FDA's Kansas City Field Office Laboratory.

Adolescent↗
PubMedDate not supplied

Determination of aluminum by neutron activation analysis in human lung tissue and in chemicals for dialysis of uremic patients.

Aluminum (Al) determination in human lung tissue, in chemicals for dialysis fluids, and in commercially available dialysis solutions is carried out using both Instrumental and Radiochemical Neutron Activation Analysis (INAA and RNAA). For some matrices, pre-and post-irradiation Al separations are tested. Chelex 100 resin and HDEHP, this latter adsorbed both on teflon and polyurethane foam, are employed for the pre-irradiation Al separations. The postirradiation procedures are performed using roughly the same schemes; the conventional Al precipitation as hydroxide is also carried out. Al values found in lungs of workers exposed to Al containing dust appear to be much higher than those found for unexposed people. Chemicals analyzed seem pure enough to give suitable dialysis solutions; for commercially available dialysis fluids, a 10-fold reduction of Al content should be convenient.

Activation Analysis↗
PubMed1981

[Preconcentration of copper (II) and mercury (II) using dithizone and carbon powder followed by neutron activation analysis (author's transl)].

A combined method of dithizone-extraction and carbon powder column adsorption was applied to concentrate trace amounts of copper (II) and mercury (II) in natural water samples before neutron activation analysis. The sample solution was adjusted to pH 1.0 with nitric acid, an aliquot of which as taken in a 500 cm3 separating funnel and then 5.0 cm3 of 0.01% dithizone-benzene and 25 cm3 of n-hexane wee added. The mixture was shaken for 10 min and stood for 30 min. After the aqueous phase was discarded, another aliquot of the sample solution was added. The above procedure was repeated until the treatment of the sample solution (1.00 dm3) was completed. The organic phase was then flown through the column (6mm phi x 50 mmh) containing carbon powder, and the resulting column was dried. The monitor containing 10 micrograms of mercury or copper was also prepared according to the above procedure. The samples and monitors were irradiated together in a pneumatic tube of JRR-3. After cooling, copper and mercury were determined by gamma-spectrometry using 64Cu, 197Hg, respectively. The recovery of trace metal ions obtained by this method was more than 99%, and the present method was found to be applicable to the preconcentration of copper (II) and mercury (II) in natural water samples.

Activation Analysis↗
PubMed1994

A study on children's condition thalassemia using neutron activation analysis and other techniques.

In this study, 50 thalassemia patients were tested using dual-energy X-ray absorptiometry (DEXA) and in vivo neutron activation analysis (IVNAA) to determine their bone mineral status. Both techniques were suitable for this purpose. Lower age was found to correspond to lower liver iron content and higher bone mineral content in the normal range. Patients undergoing treatment with transfusion had higher bone mineral content. Osteopenic patients had higher hepatic iron content than those with normal bone status. In the case of DEXA, bone mineral content (BMC) divided by height cubed was found to be a better indicator of bone mineral status than the BMD usually given. Liver density as determined by DEXA correlates well with hepatic iron.

Absorptiometry, Photon↗
PubMed1980

Mercury levels in dental students and faculty measured by neutron activation analysis.

Samples of head hair, fingernails, and toenails were taken from 61 dental students and faculty members. The mercury levels were analyzed using a simple neutron activation analysis technique which proved to be easily applicable to large numbers. Significant results were found for the head hair and fingernail groups. There may be a correlation between the higher mercury levels and increased pressure of work, which might result in decreased standards of mercury hygiene.

Faculty, Dental↗
PubMed1981

Concentration differences between serum and plasma of the elements cobalt, iron, mercury, rubidium, selenium and zinc determined by neutron activation analysis.

The differences in concentrations of cesium, cobalt, iron, mercury, rubidium, selenium and zinc between serum and plasma were examined with the aid of instrumental neutron activation analysis. Eighty serum and plasma samples obtained from 13 donors were compared. Serum was prepared in plastic tubes immediately after clotting, and plasma was separated with heparin as anticoagulant. No significant differences in the concentrations of cesium, cobalt, mercury and selenium were observed. However, the concentrations of iron, rubidium and zinc were significantly higher in serum than in plasma. The average differences were 322, 12 and 20 ng/ml for iron rubidium and zinc, respectively. The average differences found for cesium, rubidium and zinc were far below that which can be expected from a complete, or considerable release of these elements from platelets which aggregate or disintegrate during the clotting process in preparing serum.

Cobalt↗