[DETERMINATION OF GOLD IN BIOLOGICAL MATERIAL BY THE METHOD OF NEUTRON ACTIVATION ANALYSIS].
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Biological Assay↗
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Combination of neutron activation analysis, tracer techniques, and biochemical methods in the investigation of selenium metabolism.
In several studies on rats, the metabolism of selenium was investigated. The quantitative determination of the element was carried out by instrumental neutron activation analysis. For in vivo tracer experiments, 75Se-labeled selenium compounds were used. In addition to these methods, procedures for the measurement of the selenoenzyme glutathione peroxidase, and for the investigation of other selenoproteins, were applied. In this way, information on the specific pools and sites of action of the element, on biologically important selenoproteins and the regulation of the selenium metabolism, was obtained.
Animals↗
Determination of firing distance and firing angle by neutron activation analysis in a case involving gunshot wounds.
This paper reports the determination of the firing distance and a method for the evaluation of the firing angle in a fatal incident caused by two gunshots. Neutron Activation Analysis (NAA) was used to determine the Sb pattern around the bullet entrance holes on a garment of the victim, and around bullet holes produced by different shots on test targets from the gun and ammunition under investigation. The calibration curves obtained at various distances and firing angles enabled the determination of the firing distances and angles of the crime shots with a standard deviation of +/- 2 cm and +/- 5 degrees, respectively.
Axilla↗
The feasibility of well-logging measurements of arsenic levels using neutron-activation analysis.
Arsenic is an extremely toxic metal, which poses a significant problem in many mining environments. Arsenic contamination is also a major problem in ground and surface waters. A feasibility study was conducted to determine if neutron-activation analysis is a practical method of measuring in situ arsenic levels. The response of hypothetical well-logging tools to arsenic was simulated using a readily available Monte Carlo simulation code (MCNP). Simulations were made for probes with both hyperpure germanium (HPGe) and bismuth germanate (BGO) detectors using accelerator and isotopic neutron sources. Both sources produce similar results; however, the BGO detector is much more susceptible to spectral interference than the HPGe detector. Spectral interference from copper can preclude low-level arsenic measurements when using the BGO detector. Results show that a borehole probe could be built that would measure arsenic concentrations of 100 ppm by weight to an uncertainty of 50 ppm in about 15 min.
Arsenic↗
Comparison of inductively coupled plasma-atomic emission spectrometry, anodic stripping voltammetry and instrumental neutron-activation analysis for the determination of heavy metals in airborne particulate matter.
The capability of three analytical techniques, inductively coupled plasma-atomic emission spectrometry (ICP-AES), anodic stripping voltammetry (ASV), and instrumental neutron-activation analysis (INAA) have been compared for the determination of Cd, Fe, Pb, and Zn in airborne particulate matter, collected on cellulose filters, from the atmosphere of the large area of Thessaloniki, Greece. Two procedures were tested for quantitative leaching of these elements from the filters before ICP-AES and ASV, digestion with aqua regia in a Teflon autoclave, after dissolution of the organic matter with HClO4 under ambient conditions, and ultrasonic extraction with a mixture of HNO3 and HCl. Validation of the leaching and digestion procedures revealed that digestion in the autoclave is more effective, especially for Fe. The concentrations of these elements over a decade in both industrial and urban areas of the investigated region are compared.
Air Pollutants↗
Neutron activation analysis of trace elements in motor neuron disease spinal cord.
Levels of 10 trace elements were analysed in autopsied lumbar spinal cords of 38 motor neuron disease patients and 22 control subjects using instrumental neutron activation analysis. Statistically significant elevations of iron, selenium and zinc, and depletions of mercury and cesium were found in the spinal cords of motor neuron disease patients compared with control subjects. No significant correlations were found between disease duration, clinical severity or lumbar motor neuron counts and iron and selenium levels, suggesting that accumulation of these elements occur early as well as late in the disease process and therefore are not a consequence of end stage pathology. Increased iron in motor neuron disease spinal cord could act to enhance formation of reactive oxygen species. Our study supports the free radical hypothesis of neuron degeneration in motor neuron disease.
Adult↗
Neutron activation analysis for the demonstration of amphibolite rock-weathering activity of a yeast.
Neutron activation analysis was employed in a survey of weathering abilities of rock surface microorganisms. A yeast isolated from an amphibolite of a megalithic grave was found actively to concentrate, in media and in or on cells, iron and other elements when grown in the presence of ground rock. This was demonstrated by comparing a spectrum of neutron-activated amphibolite powder (particle size, 50 to 100 mum) with the spectra of neutron-activated, lyophilized yeast cells which had grown with or without amphibolite powder added to different media. The most active yeast (IFAM 1171) did not only solubilize Fe from the rock powder, but significant amounts of Co, Eu, Yb, Ca, Ba, Sc, Lu, Cr, Th, and U were also mobilized. The latter two elements occurred as natural radioactive isotopes in this amphibolite. When the yeast cells were grown with neutron-activated amphibolite, the cells contained the same elements. Furthermore, the growth medium contained Fe, Co, and Eu which had been solubilized from the amphibolite. This indicates the presence, in this yeast strain, of active rockweathering abilities as well as of uptake mechanisms for solubilized rock components.
Journal Article↗
Human nails as a biomarker of arsenic exposure from well water in Inner Mongolia: comparing atomic fluorescence spectrometry and neutron activation analysis.
Arsenic (As) is found naturally in the geological strata within the Ba Men Region of Inner Mongolia, China. A study was conducted to compare the total As measurements from two analytical techniques: instrumental neutron activation analysis (INAA) and atomic fluorescence spectrometry (AFS), and to verify nails as an exposure biomarker in this population. In 1999, nail and water samples were collected in a pilot study. Fingernails and toenails were pooled from 32 participants and analysed for total As by both INAA and AFS. Mean nail As values were 14.8+/-2.4 and 19.4+/-2.8 microg g-1 (+/-SEM) for INAA and AFS, respectively. Results from these two methods were significantly correlated (r=0.93, p<0.0001). In 2000, a second study was conducted and INAA was used to measure total As in toenails from 314 Ba Men residents. Well water samples were collected from 121 households and analysed by AFS. A significant correlation was observed between toenail and well water As (r=0.84, p<0.0001). Based on the results, INAA was significantly correlated with AFS and proved to be a reliable measure of nail As levels. In this population, toenail samples are a useful internal As exposure biomarker from drinking water sources.
Adult↗
Apparatus for the measurement of total body nitrogen using prompt neutron activation analysis with californium-252.
Details of clinical apparatus designed for the measurement of total body nitrogen (as an indicator of body protein), suitable for the critically ill, intensive-care patient are presented. Californium-252 radio-isotopic neutron sources are used, enabling a nitrogen measurement by prompt neutron activation analysis to be made in 40 min with a precision of +/- 3.2% for a whole body dose equivalent of 0.145 mSv. The advantages of Californium-252 over alternative neutron sources are discussed. A comparison between two irradiation/detection geometries is made, leading to an explanation of the geometry adopted for the apparatus. The choice of construction and shielding materials to reduce the count rate at the detectors and consequently to reduce the pile-up contribution to the nitrogen background is discussed. Salient features of the gamma ray spectroscopy system to reduce spectral distortion from pulse pile-up are presented.
Activation Analysis↗
Neutron activation analysis of calcium/phosphorus ratio in rib bone of healthy humans.
The Ca/P ratio was estimated in intact rib bone samples from healthy humans, 37 women and 45 men, aged from 15 to 55 years using instrumental neutron activation analysis. No statistically significant differences (p>0.05) age- or sex-related differences in the Ca/P ratio were observed. The mean value (M+/-SD) for the investigated parameter for the whole group studied, 2.33+/-0.34, was within a very wide range of published data and close to the median value.
Calcium↗
Neutron activation analysis determination of body composition.
The nutritional status of patients can be evaluated by monitoring changes in body composition, including the depletion of protein and muscle, adipose tissue distribution and changes in hydration status, bone or cell mass. Neutron activation analysis is a unique reference tool for the in-vivo determination of body composition. In this review we describe the recent changes in the field that followed the advent of new portable generators of fast neutrons, capable of performing elemental analysis in the clinical environment. New models were developed based on the partition of the measurable elements of the body. The recent developments help evaluate new treatments for wasting and obesity, in which change in body composition is the main outcome.
Adipose Tissue↗
DETERMINATION OF PROTEIN-BOUND IODINE (PBI) IN HUMAN PLASMA BY THERMAL NEUTRON ACTIVATION ANALYSIS.
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Activation Analysis↗
Iodine-129 as a protein label for studies of plasma protein turnover and its measurement with neutron activation analysis.
Iodine-129 (t 1/2 = 1.57 x 10(7) y) was used as a protein label for the measurement of the turnover rate of albumin in two human subjects. Plasma samples were assayed for 129I using destructive neutron activation analysis. The experiment entailed an estimated radiation dose of 0.2 muSv to the total body of the subjects. The turnover parameters showed reasonable agreement with literature values. When in a rabbit the catabolism of (129I + 131I)-labeled autologous albumin was followed, the results obtained with both labels agreed well.
Animals↗
Effects of hemodialysis on bone mineral as followed by using neutron activation analysis.
The purpose of the study was to bring a contribution to the knowledge of physiology and pathophysiology of the bone mineral heteroionic exchange with respect to sodium ions and metabolic diseases, particularly bone diseases. The instrumental neutron activation analysis was employed to follow the ratio of contents Na/Ca in bone samples from dialyzed patients. A formerly elaborated method for the determination of the Na/Ca ratio in undecalcified bone tissue sections obtained from material embedded in polymethylmethacrylate was used. In the reference group the Na/Ca ratio was of 0.021 +/- 0.003, that in patients with the renal osteopathy was of 0.030 +/- 0.007. Results obtained in patients with different types of the renal osteopathy depending on the intensity of the impairment were discussed.
Adolescent↗
Trace elements in some human milk samples by radiochemical neutron activation analysis.
Some trace element contents of samples of human milk, mainly colostrum and transitional milk, collected in the Ljubljana area of Yugoslavia, are reported. Analyses of As, Cd, Co, Cu, Hg, I, Mn, Sb, Se, Sn, V and Zn were performed by radiochemical neutron activation analysis, and the results are discussed briefly in the light of literature values.
Colostrum↗
The comparison of neutron activation analysis and photon absorptiometry at the same part-body site.
Two non-invasive methods of bone measurement were, for the first time, compared at the dame part-body site. Bone calcium, using in vivo neutron activation analysis, and bone mineral, using photon absorptiometry, were measured in the forearm in a group of renal patients. A highly significant correlation was obtained from absolute values (r = 0.91) which was reduced after normalisation (r = 0.75). Percentage changes, over periods totalling 31.3 patient years, were also highly significantly correlated (r = 0.61, P less than 0.001). The precision of the techniques accounts for the spread of the bivariate data and the estimated line of the true relationship was not significantly different from the line described if the percentage changes measured by the two techniques were equal. The two basic techniques were shown to be equally sensitive in vivo methods for monitoring calcified bone in patients suffering from metabolic bone disease.
Absorption↗
Determination of aluminum by chemical and instrumental neutron activation analysis in biological standard reference material and human brain tissue.
Since aluminum is an extremely difficult element to determine reliably in biological samples, no National Institute of Standards and Technology (NIST) biological standard reference material for tissue has yet been certified for aluminum. A chemical neutron activation analysis procedure employing anion-exchange chromatography was developed. The procedure proved successful in decontaminating radioactivatable sodium and chlorine and phosphorus which can produce aluminum via a fast neutron bombardment. For bovine liver (NIST SRM 1577 a) a value of 2.1 +/- 0.2 micrograms of aluminum/g of sample was determined, comparing favorably to the uncertified value 2 micrograms/g sample. For freeze-dried urine (NIST SRM 2670) a value of 0.18 +/- 0.01 micrograms of aluminum/mL of urine was observed. Its uncertified value is 0.18 micrograms of aluminum/mL of sample. Twenty three individual samples in three different human brains were analyzed for their aluminum content.
Aluminum↗