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PubMed1979

[Neutron activation analysis of trace elements in sea water samples (author's transl)].

Analytical values of trace elements in sea water samples have been fluctuated according to the sampling locations, the analytical procedures and so on. It is very important in marine chemistry to elucidate the cause of such concentration variations. This report is the analytical results of the samples obtained in the Pacific Ocean, the Indian Ocean and the Sea of Japan, by means of neutron activation analysis. As the preconcentration, APDC-chelate extraction and freeze-drying were adopted. The specimens obtained by this extraction from 500 or 800 ml samples were irradiated by KUR reactor for 1 min, 1 hr to 10 hrs and the gamma-ray spectrometry with a Ge(Li) detector was used for the determination of V, Mn, Cu, Zn, U, Fe, Co, Ni, Ag, Sb and Au. By about 80 hrs irradiation of the specimens obtained by freeze-drying from 20 ml samples and their gamma-ray spectrometry, Sc, Cr, Fe, Co, Zn, Rb, Sr, Ag, Sb and Cs were determined. The former procedure gives concentrations of elements in species reactable with APDC, but the latter method shows entire concentrations of the elements in the sea water samples. Some considerations on the analytical values and the comparisons of the both methods are described.

Activation Analysis↗
PubMed1990

Prompt gamma-ray neutron activation analysis of boron-10 in biological materials.

Prompt gamma-ray neutron activation analysis of 10B concentrations in biological samples was carried out using a germanium detector and single crystal silicon filtered neutron beams from the TRIGA-II reactor. The 10B concentrations of biological samples such as tumors, tissues, blood and cultured cells were estimated from calibration curves obtained by using standard samples containing various 10B concentrations. A method of measuring absolute 10B concentrations was also presented.

Boron↗
PubMed1991

Microwave acid digestion and preconcentration neutron activation analysis of biological and diet samples for iodine.

A simple preconcentration neutron activation analysis (PNAA) method has been developed for the determination of low levels of iodine in biological and nutritional materials. The method involves dissolution of the samples by microwave digestion in the presence of acids in closed Teflon bombs and preconcentration of total iodine, after reduction to iodide with hydrazine sulfate, by coprecipitation with bismuth sulfide. The effects of different factors such as acidity, time for complete precipitation, and concentrations of bismuth, sulfide, and diverse ions on the quantitative recovery of iodide have been studied. The absolute detection limit of the PNAA method is 5 ng of iodine. Precision of measurement, expressed in terms of relative standard deviation, is about 5% at 100 ppb and 10% at 20 ppb levels of iodine. The PNAA method has been applied to several biological reference materials and total diet samples.

Food Analysis↗
PubMed2001

Elemental analysis of two Egyptian iron ores and produced industrial iron samples by neutron activation analysis.

Elemental analysis of two iron ores and initial industrial iron production prepared by the Egyptian Iron and Steel Company of Helwan near Cairo were performed by the instrumental neutron activation analysis technique. Five samples of each type were irradiated for 48 h in a thermal neutron flux of 4 x 10(12) n/cm2 s in the first Egyptian research reactor ET-RR-1. Also, the Pneumatic Irradiation Rabbit System (PIRS), attached to the reactor ET-RR-1 in Inshass, was used to measure short-life elements. The gamma-ray spectra were obtained with a hyper pure germanium detection system. The concentration percentage values of major, minor and trace elements are presented. Implications of the elemental concentration values obtained are presented.

Journal Article↗
PubMed2000

Multi-element analysis of emeralds and associated rocks by k(o) neutron activation analysis

Multi-element analysis was carried out in natural emeralds, their associated rocks and one sample of beryl obtained from Rajasthan, India. The concentrations of 21 elements were assayed by Instrumental Neutron Activation Analysis using the k0 method (k0 INAA method) and high-resolution gamma ray spectrometry. The data reveal the segregation of some elements from associated (trapped and host) rocks to the mineral beryl forming the gemstones. A reference rock standard of the US Geological Survey (USGS BCR-1) was also analysed as a control of the method.

Journal Article↗
PubMed1980

Accurate analysis of stable isotopes 68Zn, 70Zn, and 58Fe in human feces with neutron activation analysis.

Accurate isotopic analysis of human fecal samples is discussed in relation to mineral bioavailability studies of human subjects. It is shown that for bioavailability investigations of Zn and Fe, the method of neutron activation analysis is suitable for routine application to clinical experiments; and the human fecal samples resulting from diet suitably enriched in isotopes 70Zn and 58Fe can be routinely analyzed with relative precisions of about 1% for the isotopes 68Zn, 70Zn and 58Fe.

Feces↗
PubMed1983

Determination of trace elements in human whole blood by instrumental neutron activation analysis.

The trace element composition of whole blood has been investigated by instrumental neutron activation analysis (INAA). The blood samples of 80 individuals of adult population in Taiwan were analyzed. The samples were lyophilized, irradiated together with synthetic standards, and determined gamma-spectrometrically. The concentrations of 7 elements, Cr, Co, Fe, Rb, Sc, Se and Zn were simultaneously determined. The reliability of the analysis was checked with NBS bovine liver reference standard material. The frequency distributions of all the elements measured are presented and the results are compared with available data.

Activation Analysis↗
PubMedDate not supplied

Instrumental neutron activation analysis of geological and biological reference materials using the ko-standardization method.

The ko-standardization method used in instrumental neutron activation analysis (INAA) was applied to the determination of some elements in geological and biological reference materials. We analyzed NBS SRM 1572 Citrus Leaves and SRM 1645 River Sediment and the CRM materials, IAEA Soil-7, SL-1, and MA-A-2. Comparison is made with reference values whenever available. Good agreement is found. The potential of the ko-standardization method in reactor INAA is discussed.

Animals↗
PubMed1982

[A new correction method for radionuclide formation in neutron activation analysis using a reactor power meter coupled with a microcomputer].

Neutron flux and irradiation time should be accurately known in neutron activation analysis using very short lived nuclides in which conventional monitoring methods i.e., a comparator method, flux monitor method and so on cannot be used satisfactorily. Especially, fluctuation of neutron flux has not been corrected. We noted a change of reactor power at a pneumatic operation, and found out a new correction method for its correction in activation analysis. In our small nuclear reactor, TRIGA-II, the reactor power increased rapidly a few % when a pneumatic-operated capsule arrived at a core of the reactor, and decreased when the capsule left from the core. If the duration between these two changes of the reactor power is equal to the irradiation time, and that the reactor power is proportional to the neutron flux, we can regard an activity formation as a time integration of the reactor power. Then, the correction system was made of a reactor power meter, a V-F converter (voltage to frequency converter), a clock time, a counter, a microcomputer, electric circuits and so on. The signal of the reactor power during the irradiation was counted through the V-F converter, and was accumulated in a memory of the microcomputer. The neutron fluence was calculated in this microcomputer. This method was examined by means of activation of copper and selenium standard samples by 9-11 sec irradiations. The observed activity involved +/- 10% error. However, the error in the corrected activity was decreased to a few % using this correction method. As a result, we found that this method can be used to obtain accurate value for radionuclide formation.

Activation Analysis↗
PubMedDate not supplied

Determination of selected trace elements in foodstuffs and biological materials by destructive neutron activation analysis.

Concentration of trace elements in Nescafé, Fariman sugar, and Sadaf turmeric and mercury content in cancerous blood were determined by radiochemical, neutron activation analysis. By this separation method levels of 110mAg, 198Au, 203Hg, 76Se, 51Cr, 24Na, 42K, 99Mo, 122Sb, 82Br, 59Fe, 60Co were measured without interference in the gamma spectroscopy. A nondestructive method has also been used for the analysis of sodium, potassium, and bromine.

Food Analysis↗
PubMedDate not supplied

Study of chemical element behavior in health and disease by means of neutron activation analysis and multivariate statistics.

An attempt was undertaken to estimate the contribution of individual chemical elements to the rise of arterial hypertension. Instrumental neutron activation analysis was used to determine the concentrations of 23 chemical elements in hair of patients and healthy subjects. Mean concentrations as well as relationships between elements in both groups were calculated and compared. Discriminant function was obtained, which allows the division of patients and healthy subjects into two groups.

Adult↗
PubMed2004

Analysis of bioactive ingredients in the brown alga Fucus vesiculosus by capillary electrophoresis and neutron activation analysis.

Two different types of bioactive components of the seaweed Fucus vesiculosus were analysed: (1) polyphenols (phlorotannins) by capillary electrophoresis (CE) and (2) mineral part (including bioactive microelements) by neutron activation analysis (NAA). CE experiments were carried out using a UV detector (at 210 nm) and an uncoated silica capillary. The best separation was achieved at a voltage of 20 kV using borate or acetate buffer in a methanol/acetonitrile mixture as background electrolyte. The CE analysis data were confirmed by high-performance liquid chromatography (HPLC). Determination of mineral composition of algal biomass by NAA was performed on the basis of various nuclides; the best results (from 38 elements determined) were obtained for Mn, Fe, Zn, As, Br, Sr, I, Ba, Au and Hg.

Chromatography, High Pressure Liquid↗
PubMed1999

Instrumental neutron activation analysis of rib bone samples and of bone reference materials.

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.

Neutron Activation Analysis↗
PubMed1981

Neutron activation analysis of nickel purified by floating zone-refining and anion exchange.

Nondestructive neutron activation analysis was performed on the nickel purified by floating zone-refining and anion exchange. It is found that floating zone-refining in vacuum is effective to remove Na, Sc, Cr, Zn, As, Ag, Sb and Hg through vaporization in addition to elimination of Se, Sb, Ta, Sm and Tb through segregation. Anion exchange method is also effective to separate Fe, Co, Zn, Mo, Hg, Th and U usually contained in the commercial nickel sources. It is concluded that combination of these two purification methods is required to obtain high purity nickel, since floating zone-refining is known ineffective to eliminate Fe and Co, main impurities in commercial nickel sources.

Activation Analysis↗
PubMed1983

[Determination of Ca/P atomic ratio in calcium-hydroxyapatite by neutron activation analysis].

The Ca/P atomic ratios of synthesized calcium-hydroxyapatite (Ca10(PO4)6(OH2) were determined by neutron activation analysis. In order to obtain calibration curves, the standard samples, such as calcium monohydrogenphosphate, calcium dihydrogenphosphate, etc., were prepared. gamma and beta ray spectra, and beta ray intensities of calcium-hydroxyapatite and standard samples irradiated with reactor neutrons were measured by using a Ge(Li) detector, a low background beta ray spectrometer and GM detector. Based on these results, deviation coefficient of the calibration curve, accuracy of the Ca/P atomic ratio, minimum determination limit, etc. were compared in detail. From the present analysis, the Ca/P atomic ratio of calcium-hydroxyapatite was able to obtain with the standard deviation of about 2% for 1 mg sample.

Activation Analysis↗
PubMed1987

Measurement of total body chlorine by prompt gamma in vivo neutron activation analysis.

A method of measuring total body chlorine (TBCl) by prompt gamma in vivo neutron activation analysis is described which depends on the same NaI(Tl) spectra used for determinations of total body nitrogen. From these spectra counts ratios of chlorine to hydrogen are derived and TBCl is determined using a model of body composition which depends on measured body weight, total body water (by tritium dilution) and protein (6.25 X nitrogen) as well as estimated body minerals and glycogen. The precision of the method based on scanning an anthropomorphic phantom is at present only approximately 9% (SD), for a patient dose equivalent of less than 0.30 mSv. Spectra collected from 67 normal volunteers (32 male, 35 female) yielded mean values of TBCl of 72 +/- 19 (SD) g in males and 53.6 +/- 15 g in females, in broad agreement with values reported by workers using delayed gamma methods. Results are also presented for two human cadavers analysed both by neutron activation and by conventional chemical analysis; the ratios of TBCl (neutron activation) to TBCl (chemical) were 0.980 +/- 0.028 (SEM) and 0.91 +/- 0.09. Finally, it is suggested that an improvement in precision will be achieved by increasing the scanning time (thereby increasing the radiation dose equivalent) and by adding two more detectors.

Adult↗
PubMedDate not supplied

Determination of sodium in biological materials by instrumental neutron activation analysis.

A formalized method for determining sodium in biological materials by instrumental neutron activation analysis is presented. The method includes common procedures from the numerous options available to this historically nonformalized analytical technique. The number of procedural options is restricted to minimize the method's complexity, yet the method is still applicable to a variety of neutron activation facilities. High accuracy and precision are achieved by placing bounds on allowed uncertainty at critical stages of the analysis. Analytical results from the U.S. Food and Drug Administration laboratory and 4 other laboratories demonstrate the method's performance.

Absorption↗