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PubMed1986

Body composition of Atlantic salmon (Salmo salar L.) studied by neutron activation analysis.

This paper describes the measurement of whole body Ca, Cl, K, N, Na, O and P in Atlantic salmon parr, adults and kelts by neutron activation analysis (NAA). This technique is based on counting the specific gamma activity in samples which is present naturally or is produced by neutron irradiation. Body composition (fat, mineral, protein and water) are estimated from these data. NAA has advantages over chemical methods with the potential for in vivo measurements. Anthropogenic 137Cs was found in sea-water (SW) salmon but not found in the freshwater (FW) stages (parr and kelts). Presence of this isotope in fish caught in FW indicates recent SW residence.

Aging↗
PubMed1979

Development of apparatus to measure calcium changes in the forearm and spine by neutron activation analysis using californium-252.

Techniques were developed to measure small changes of calcium in the forearm and spine in vivo by neutron activation analysis using two sources of 252Cf in a hospital environment. Using purpose-built part-body counters and bilateral irradiation with 7.5 cm premoderation between the sources and the bone, peripheral bone was measured with a total source strength eventually as low as 50 mCi. Two methods of spectral analysis were used and compared. Patient studies of the forearm were successfully undertaken, with a precision of 2.6% which included patient movement, and an annual bone dose of less than 10 rem and skin dose of 35 rem from six measurements. Two 100 mCi sources were used for measurements of the lumbar spine. Care was taken to minimise the problems of non-uniformity of activation which are present using unilateral irradiation. Emphasis was placed on measuring the bodies of the vertebrae with adequate sensitivity and uniformity, and the spinous processes and arches with low sensitivity. A whole body counter was used for the bilateral detection of the induced activity. The precision of the method was 3.0% with an annual peak bone dose of 2.1 rem and skin dose of 18 rem from three measurements.

Activation Analysis↗
PubMed1979

Neutron activation analysis of trace elements in skin. VIII. Selenium in normal skin.

Selenium(Se) has been determined in skin by neutron activation analysis applying selective irradiation and cooling time, followed by measurement of the activity on a high resolution germanium lithium (Ge(Li)) detector. The levels and distribution of Se in normal abdominal and plantar skin, together with other available evidence, lead us to believe that it is an essential trace element in man. It is suggested that Se has an essential role in skin keratinization.

Abdomen↗
PubMed1997

Monte Carlo design study of a moderated 252Cf source for in vivo neutron activation analysis of aluminium.

The Monte Carlo computer code MCNP has been used to design a moderated 252Cf neutron source for in vivo neutron activation analysis of aluminium (Al) in the bones of the hand. The clinical motivation is the need to monitor Al body burden in subjects with renal dysfunction, at risk of Al toxicity. The design involves the source positioned on the central axis at one end of a cylindrical deuterium oxide moderator. The moderator is surrounded by a graphite reflector, with the hand inserted at the end of the moderator opposing the source. For a 1 mg 252Cf source, 15 cm long x 20 cm radius moderator and 20 cm thick reflector, the estimated minimum detection limit is 0.5 mg Al for a 20 min irradiation, with an equivalent dose of 16.5 mSv to the hand. Increasing the moderator length and/or introducing a fast neutron filter (for example silicon) further reduces interference from fast-neutron-induced reactions on phosphorus in bone, at the expense of decreased fluence of the thermal neutrons which activate Al. Increased source strengths may be necessary to compensate for this decreased thermal fluence, to allow measurements to be made within an acceptable time limit for the comfort of the patient.

Aluminum↗
PubMed1979

[8-Quinolinol-5-sulfonic acid-loaded resin as a preconcentrating agent in the neutron activation analysis of the chalcophile elements (author's transl)].

A chelating agent-loaded resin consisting of 8-quinolinol-5-sulfonic acid and an anion-exchange resin (HOx-resin) was prepared in order to concentrate trace chalcophile elements in natural water samples selectively before neutron activation analysis. The exchange capacity of the Diaion SA No. 100 for the reagent (1.8 meq . g-1 resin) corresponds approximately to that for chloride ion (1.83 meq . g-1 resin), indicating that 8-quinolinol-5-sulfonic acid is adsorbed quantitatively on the exchange site of the resin through the sulfonate anion in the reagent. The basic conditions for the adsorption of the metal ions on the resin were investigated by employing the column method. The nitrate concentration and the pH of the sample solution affect the adsorption behavior of metal ions. Several solutions containing metal ions with varying pH or varying nitrate concentration were applied to the resin column (35 mm x 7 mm phi) with a flow rate of 2.0 cm3 . min-1. As a result, the optimum conditions for the quantitative adsorption of copper(II), zinc(II), cadmium(II), cobalt(II), nickel(II) and manganese(II) were as follows: NO3- less than 0.01 mol . dm-3 pH greater than 4.6. Furthermore, the feasibility of the above conditions as well as quantitative adsorption of the chalcophile elements was confirmed through the neutron activation analysis of the synthesized metal solutions.

Activation Analysis↗
PubMed2000

A search for trace elements in some human intracranial tumors by instrumental neutron activation analysis.

A investigation was undertaken to measure the presence of trace elements in some intracranial tumors using the instrumental neutron activation analysis technique. The following 20 minor and trace elements were investigated: Na, Mg, Al, P, Cl, K, Ca, Cr, Mn, Fe, Co, Cu, Zn, As, Se, Br, Rb, Sb, I, and Cs. Our results are compared with other trace element analyses in human brain tissue.

Adult↗
PubMed1994

Evaluation of the washing system efficiency in sugar cane mills by neutron activation analysis.

The effectiveness of industrial washing operation in minimizing soil in sugar cane delivered to mills is evaluated. Instrumental neutron activation analysis was the nuclear analytical technique chosen for this work, with Fe, Hf, Sc, and Th selected as soil tracers. On the basis of differences between elemental concentration of integral and prepared cane, that is before and after washing, the feasibility of the method for evaluation of the washing efficiency is demonstrated.

Brazil↗
PubMed2005

Characterization of trace elements in Casearia medicinal plant by neutron activation analysis.

Leaves of Casearia sylvestris, Casearia decandra and Casearia obliqua plant species, collected at the Atlantic Forest in Brazil, were analyzed by using instrumental neutron activation analysis (INAA). Short and long irradiations using thermal neutron flux of the IEA-R1 nuclear reactor were carried out for these analyses. Concentrations of Ca, K and Mg were found in these samples at the percentage levels, Br, Cl, Fe, Mn, Na, Rb and Zn at the microg g(-1) levels and Co, Cr, Cs, La, and Sc at the microg kg(-1) levels. Comparisons were made among the element concentrations obtained in these three Casearia species and significant differences were found for the elements Cl, Co, Cs, Cr, La, Mn, Na and Sc. The precision and the accuracy of the results were evaluated by analyzing the certified reference materials NIST-1515 Apple Leaves and NIST-1573a Tomato Leaves.

Casearia↗
PubMed1993

Differentiation of elemental composition of normal and malignant breast tissue by instrumental neutron activation analysis.

Multi-elemental quantitative analyses of 15 paired samples of normal and malignant human breast tissue by instrumental neutron activation analysis are reported. The elements, Al, Br, Ca, Cl, Co, Cs, Fe, K, Na, Rb, Zn were detected. Significantly elevated concentration levels were found for Al, Br, Ca, Cl, Cs, K, Na, Zn in malignant compared to normal tissue. Although the role of elemental composition in breast cancer is unclear, this finding may be of importance as another parameter for differentiating normal from malignant tissue.

Breast↗
PubMed1999

Investigation of selenium distribution in subcellular fractions of human liver by neutron activation analysis.

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.

Adult↗
PubMed1989

Calibration and evaluation of a 252Cf-based neutron activation analysis instrument for the determination of nitrogen in vivo.

A novel clinical instrument for multi-element in vivo neutron activation analysis has been recently constructed in Swansea. The instrument is intended primarily for prompt gamma measurement of total and partial body calcium, total body nitrogen and partial body cadmium. For the measurement of nitrogen the subject is scanned both prone and supine across a vertical collimated neutron beam from a 4 GBq 252Cf source. Two shielded Nal(TI) detectors, each of volume 2760 cm3, are placed above the subject on the opposite side to that irradiated. The prompt gamma ray spectrum contains prominent peaks from hydrogen, nitrogen, chlorine and carbon. The optimisation, calibration and evaluation of the instrument for the measurement of nitrogen, by the reaction 14N(n, gamma)15N, is described. The calibration corrects the ratio of nitrogen-to-hydrogen counts measured from the subject for background gamma rays and the effects of body habitus. Body hydrogen is use as as internal standard. Repeated measurements of a homogeneous anthropomorphic phantom indicate that the ratio of nitrogen-to-hydrogen counts may be determined by a coefficient of variation of 1.6% for a neutron dose equivalent incident on the phantom of 0.45 mSv (QF = 10). The accuracy of the calibration was assessed by measuring three anthropomorphic phantoms (weight range: 41.4-110 kg) containing simulated skeletons and the major organs of the body. For these phantoms the mean discrepancy of the measured to the known nitrogen content was +4.9%. The simultaneous measurement of chlorine and carbon is discussed.

Activation Analysis↗
PubMed1982

Detection of repeated arsenical poisoning by neutron activation analysis of foot nail segments.

In one case of repeated ingestions of arsenic over a period of one year, the value of sectional toe nail analysis was investigated. The arsenic determinations were performed by instrumental neutron activation analysis. After subdividing the nail transversely into segments of 0.5 mm length, several maxima and minima of arsenic concentrations were found. Taking the nail growth into consideration, these characteristics of curve correspond to the known dates of treatments and of dismissals from the hospital. The results exclude an external arsenic contamination of the nail.

Adult↗
PubMed1967

Tissue copper determinations by neutron activation analysis.

A method is described for the handling of tissue samples for copper determination by neutron activation analysis. The results obtained for normal liver copper estimations compared favourably with results obtained by conventional methods.

Activation Analysis↗
PubMed1978

Determination of chromium and cobalt in human serum by neutron activation analysis.

Confusion exists about the chromium and cobalt concentrations in the serum of healthy individuals. We determined these elements by neutron activation analysis. The samples were irradiated during 12 days at a flux of approximately 10(14) neutrons.cm-2.s-1. Chromium was selectively separated by distillation after the irradiation. We obtained the following values (mean +/- standard deviation): 0.160 +/- 0.083 mug/liter for chromium, and 0.108 +/- 0.060 mug/liter for cobalt.

Blood↗