Showing papers in "Journal of Radioanalytical and Nuclear Chemistry in 1979"
TL;DR: In this paper, a new method is developed for instantaneous α-determination in the 1/E1+α epithermal neutron spectrum using coirradiation of three bare resonance detectors, followed by gamma-counting on a calibrated Ge(Li)-detector.
Abstract: A new method is developed for instantaneous α-determination in the 1/E1+α epithermal neutron spectrum. It is based on coirradiation of three bare resonance detectors, followed by gamma-counting on a calibrated Ge(Li)-detector. The technique is applied in two channels of the Thetis reactor (Gent) and the results are critically compared with those obtained by other methods.
79 citations
TL;DR: In this paper, the two-detector method of RYVES is modified by using Cd-ratio measurements, thus eliminating the introduction of systematic errors due to the inaccuracy of absolute nuclear data.
Abstract: Some methods described in the literature for the determination of α in the 1/E1+α epithermal neutron spectrum are critically reviewed with respect to their accuracy. The multi resonance—detector method with Cd-covered irradiations, as used by SCHUMANN and ALBERT, is generalized by subtracting the epithermal 1/v-tail and by introducing the effective resonance energy, as defined by RYVES. The two-detector method of RYVES is modified by using Cd-ratio measurements, thus eliminating the introduction of systematic errors due to the inaccuracy of absolute nuclear data. The adapted methods are applied in channel 15 of the Thetis reactor (Gent).
76 citations
TL;DR: In this paper, a new standardization method has been developed for neutron activation analysis, where experimental activation constants, are determined for a given reactor power level and irradiation and counting position, without flux monitor or standards are needed due to the exceptional stability of the reactor used.
Abstract: A new standardization method has been developed for neutron activation analysis. In this method, experimental activation constants, are determined for a given reactor power level and irradiation and counting position. The unusual feature of this technique is the fact that no flux monitor or standards are needed due to the exceptional stability of the reactor used. The semi-absolute method was tested over a three month period and its reliability was demonstrated for 6 elements of different neutrons cross-section characteristics.
73 citations
TL;DR: In this article, the previously established technique of analysis of neutron capture γ-rays for the determination of nitrogen in-vivo has been modified to make estimates of absolute quantities of nitrogen mass.
Abstract: The previously established technique of analysis of neutron capture γ-rays for the determination of nitrogen in-vivo has been modified to make estimates of absolute quantities of nitrogen mass. Hydrogen is used as an internal standard and the nitrogen mass is determined from the observed ratio of nitrogen to hydrogen counts, together with the hydrogen mass, estimated from body parameters. Phantom and cadaver studies indicate that nitrogen mass can be estimated to ±4% or better by this means.
68 citations
TL;DR: In this paper, the effective resonance energy (EEE), introduced by RYVES, is a useful parameter for the correction of resonance integrals in non-ideal epithermal neutron spectra, which can be approximated by a 1/E1+α-flux distribution.
Abstract: The present paper shows that the effective resonance energy
$$\overline {E_r } $$
introduced by RYVES, is a useful parameter for the correction of resonance integrals in non-ideal epithermal neutron spectra, which can be approximated by a 1/E1+α-flux distribution. The definition, the characteristics and the calculation of
$$\overline {E_r } $$
are discussed thoroughly. Tabulations are included, giving
$$\overline {E_r } $$
for 96 isotopes.
64 citations
TL;DR: A tabulation is given of recommended Q0-values for 107 reactions of interest in NAA, including a revision and updating of formerly published results for 57 isotopes.
Abstract: In the present paper, a tabulation is given of recommended Q0-values [the ratio of the resonance integral (I0) to the 2200 m·s−1 cross-section (δ0)] for 107 (n, γ) reactions of interest in NAA, including a revision and updating of formerly published results for 57 isotopes. The values were either critically evaluated from literature, or-in the majority of cases — experimentally determined according to the Cd-ratio method, with a correction for a non-ideal epithermal neutron flux distribution. These Q0-measurements were performed at INW, Gent, at KFKI, Budapest, and occasionally at Riso. A comparison is made with results obtained by other workers or with values derived from δ0's and I0's quoted in recent compilations.
59 citations
TL;DR: In this paper, the authors used different methods of calculation and obtained a net accumulation rate in the range of 0.0078-0.44 g·cm−2·year−1.
Abstract: 210Pb datings of sediments from open marine area, salt marsh area and estuary and of peat from a raised bog have been performed. Different methods of calculation are used. Net accumulation rates in the range of 0.0078–0.44 g·cm−2·year−1 were obtained. The results are in good agreement with those obtained by other methods.
54 citations
TL;DR: The rates at which six small aminopolycarboxylate chelates of trivalent111In and three protein-bound chelate of111In deliver indium to the serum protein transferrin have been studied in sterile human serum.
Abstract: The rates at which six small aminopolycarboxylate chelates of trivalent111In and three protein-bound chelates of111In deliver indium to the serum protein transferrin have been studied in sterile human serum at pH 7.3, 37°C. Sterically hindered chelates containing a substituent on an ethylene carbon of EDTA decompose with rates in the range 0.03 to 0.11% per day—one to two orders of magnitude slower than other chelates. Only small differences are observed between rates of decomposition for low-molecular-weight chelates and for protein-bound chelates having analogous structures.
46 citations
TL;DR: In this article, a multielement analysis of human hair was carried out to elucidate the levels of various trace element concentrations in hair of local population in the Tokyo metropolitan area.
Abstract: Applying instrumental neutron activation analysis, multielement analysis of human hair was carried out to elucidate the levels of various trace element concentrations in hair of local population in the Tokyo metropolitan area. 202 hair samples were collected from the inhabitants classified by sex and five age groups. Using several combinations of irradiation time, cooling time and counting time, forty elements were quantitatively analyzed. The method of analysis for data including samples under detection limit is discussed, assuming that the frequanecy distribution of trace element contents in hair is log-normal.
43 citations
TL;DR: In this article, a brief description of cyclic activation analysis includes both a theoretical interpretation, by way of graphical representations and experimental considerations, for the determination of the concentration of elements by measurement of short-lived isotopes.
Abstract: This brief description of cyclic activation analysis includes both a theoretical interpretation, by way of graphical representations and experimental considerations, for the determination of the concentration of elements by measurement of short-lived isotopes. Particular attention is given to the effect of sample transfer and the half-life of the background matrix. The use of a Ge(Li) detector and a low energy photon detector of intrinsic Ge, are also summarily discussed based on the experience of the authors' work in biological and environmental samples and the establishment of rapid, routine, multielemental and instrumental techniques.
39 citations
TL;DR: In this paper, a preliminary study of 134Cs,137Cs,210Pb,226Ra and228Ra in the Clyde Sea Area has been performed and a summary of the marine geochemistries of these species and a detailed account of methods involved in their routine analysis are described.
Abstract: Multi-radionuclide analyses of coastal marine sediments and seawater can be of considerable value in defining rates and mechanisms of nearshore processes. A preliminary study of134Cs,137Cs,210Pb,226Ra and228Ra in the Clyde Sea Area has been performed. A summary of the marine geochemistries of these species and a detailed account of methods involved in their routine analysis are described.
TL;DR: In this paper, the concentration of 15 elements in various brands of cigarette tobacco and cigarette wrapping paper were determined using instrumental neutron activation analysis, and the paper of some of the brands contains higher concentrations of toxic elements than the tobacco.
Abstract: The concentration of 15 elements in various brands of cigarette tobacco and cigarette wrapping paper were determined using instrumental neutron activation analysis. The paper of some of the brands contains higher concentrations of toxic elements than the tobacco. The cigarette filter and the ash were also analyzed to determine the adsorption of toxic elements on the filter and their transference in smoke. The toxic effects of some of the elements have been briefly discussed.
TL;DR: In this paper, the pertechnetate ion is more effective when it is coordinated to a cation solvated by tributylphosphate than the extraction in the form of per technetate acid.
Abstract: The extraction of the pertechnetate anion has been investigated in the systems tributylphosphate (TBP)—solvent (carbon tetrachloride, n-heptane, chloroform)—metal salt (uranyl nitrate and chloride, thorium nitrate)—ammonium salt. In the absence of a metal, the solvates HTeO4. iTBP (i=4) are extracted, while in the presence of uranium and thorium, the distribution of technetium corresponds to the formation of the mixed complexes: UO2(NO3)(TeO4)·2TBP, UO2Cl(TcO4)·2TBP and Th(NO3)3 (TcO1)·2TBP. The effective constants of the reactions H++TcO4−+i(TBP)org←(HTcO1·iTBP)org, and (MLn·2TBP)org+TcO4−←(MLn−1TcO4·2TBP)org+L were established in the above systems. The extraction of pertechnetate ion is more effective when it is coordinated to a cation solvated by TBP than the extraction in the form of pertechnetate acid solvated by TBP.
TL;DR: In this paper, a catalogue of observed gamma-rays is given which lists their calculated interference-free sensitivities for analysis, and Spectra of elements which potentially may be determined or which provide serious interference in the determination of other elements are illustrated.
Abstract: Alpha induced prompt gamma-rays generated by excitation, or in nuclear reactions, were studied for 56 elements to select those elements having gamma-rays of sufficient intensity for analytical application. A catalogue of observed gamma-rays is given which lists their calculated interference-free sensitivities for analysis. Spectra of elements which potentially may be determined or which provide serious interference in the determination of other elements are illustrated, together with a compilation in increasing order of energy of all observed gamma-rays.
TL;DR: In this article, the effect of complexing agents (EDTA, oxalate, tartrate and 5-sulfosalicylic acid) on the sorption of europium (III) on iron(III) oxide has been studied.
Abstract: The sorption of small amounts of europium(III) on iron(III) hydroxide and oxide has been studied as a function of pH. The mechanism of sorption is discussed. Optimum conditions have been found for the preconcentration of small or trace amounts of europium(III) by iron(III) hydroxide and oxide. The influence of complexing agents (EDTA, oxalate, tartrate and 5-sulfosalicylic acid) on the sorption of small amounts of europium(III) on iron(III) oxide has also been studied.
TL;DR: In this paper, a high resolution Ge(Li) gamma ray spectrometer was used to determine the concentration of Al, As, Au, Br, Ca, Cd, Co, Cr, Cu, Fe, La, Mn, Mo, Sb, Se, W, and Zn in Cumin, coriander, carrots, and Daucus carrota (Umbelliferae Family), alfalfa, Kidney bean, phaseolus sativus, Phaseolus vulgaris, bean, lenses, and fenugreek (
Abstract: Neutron activation analysis, NAA, a high resolution Ge(Li) gamma ray spectrometer was used to determine the concentration of Al, As, Au, Br, Ca, Cd, Co, Cr, Cu, Fe, La, Mn, Mo, Sb, Se, W, and Zn in Cumin, coriander, carrots, and Daucus carrota (Umbelliferae Family), alfalfa, Kidney bean, Phaseolus sativus, Phaseolus vulgaris, bean, lenses, and fenugreek (Legumirosae Family). Multielement determination technique on destructive and nondestructive samples was followed. This method is simple, precise and sensitive to 17 trace elements.
TL;DR: The nuclear microprobe is a spatially sensitive analytical instrument which exploits measurement of the particles or other radiations emitted when specimens are irradiated with beams of energetic charged particles, most often having energies lying the range 0.5-4 MeV as discussed by the authors.
Abstract: The nuclear microprobe is a spatially sensitive analytical instrument which exploits measurement of the particles or other radiations emitted when specimens are irradiated with beams of energetic charged-particles, most often having energies lying the range 0.5–4 MeV. Factors affecting the analytical and technical performance are discussed and examples given of application of the instrument to the fields of nuclear science and metallurgy, biology and geology.
TL;DR: In this paper, the fission track registration technique using Makrofol KG as detector and the wet method was developed for the determination of microgram amounts of uranium in water samples.
Abstract: The fission track registration technique using Makrofol KG as detector and the wet method was developed for the determination of microgram amounts of uranium in water samples. This method allows the determination of uranium concentrations within the interval of 8.0 to 0.4 μg. U/l, the overall ranging from 3.3% to 29.0%. Results obtained for water samples from several sources in the State of Sao Paulo, Brasil, are reported.
TL;DR: In this paper, the single comparator method in neutron activation analysis has been applied to the investigation of the purity of silicon single-crystals of different origins, and the following impurities were determined: Au, Sb, Co, Cu and Na.
Abstract: The single comparator method in neutron activation analysis has been applied to the investigation of the purity of silicon single-crystals of different origins. The following impurities were determined: Au, Sb, Co, Cu and Na. Studies were also carried out on the surface contamination of silicon samples introduced through steps of sample preparation and irradiation. Up to nineteen elements on the surface of samples were analysed and found to be easily reduced to low levels or detection limits by washing and etching.
TL;DR: In this paper, the possibilities of trace element adsorption on different adsorbents are investigated and three procedures are described' (a) adhering on activated charcoal at pH 8.5, (b) adsorbing activated charcoal in presence of dithizone at pH8.5 and (c) adhocariminate at pH 5.5.
Abstract: The possibilities of trace element adsorption on different adsorbents are investigated. Three procedures are described' (a) adsorption on activated charcoal at pH 8.5, (b) adsorption on activated charcoal in presence of dithizone at pH 8.5 and (c) adsorption on activated charcoal in presence of sodium diethyldithiocarbaminate at pH 5.5. Of the 23 elements which have been investigated in detail using standardised samples of water the following are determined quantitatively within an error of 10% according to procedure (a) and (b) Au, Cr, Eu, Hg, La, Sc, U and Zn, according to procedure (b) also Cd. The elements Ag, As, Ce, Fe and Se are adsorbed according to procedure (a) and (b) with yields between 60 and 90%, according to procedure (b) also Co. Mo is adsorbed by procedure (c) quantitatively. Cu is not detected after a decay time of 3 days. Sb is adsorbed by all procedures with low yields between 18 and 56%. The elements Br, Ca, Cl, K and Na remain mainly in the solution. The decontamination factors for these elements range between 102 and 106 (Na). Water from the North Sea is analysed by procedure (b).
TL;DR: In this article, a scheme for the analysis of all 14 rare earth elements in rocks by neutron activation analysis using a group of radiochemical separation is described, taking particular account of the difficult rare earth element elements and is designed to minimise both γ-spectrometer counting time and overall analysis time.
Abstract: A scheme is described for the analysis of all 14 rare earth elements in rocks by neutron activation analysis using a group of radiochemical separation. The scheme takes particular account of the ‘difficult’ rare earth elements and is designed to minimise both γ-spectrometer counting time and overall analysis time.
TL;DR: In this article, a possible way to do homogeneity tests on many elements is offered by instrumental neutron activation analysis, which allows the quick evaluation of sample homogeneity on very small samples and for many elements simultaneosly.
Abstract: Homogeneity is the first and most essential prerequisite of a reference material which merits this marking. A possible way to do homogeneity tests on many elements is offered by instrumental neutron activation analysis. It is shown that this method allows the quick evaluation of sample homogeneity on very small samples and for many elements simultaneosly, regarding macro as well as ultra trace elements.
TL;DR: In this article, the effects of radiation on the extraction system composed of DEHPA extractant and DTPA aqueous solution containing nitrate were studied by measuring distribution ratios of Am(III) and Nd(III).
Abstract: Effects of radiation on the extraction system composed of DEHPA extractant and DTPA aqueous solution containing nitrate were studied by measuring distribution ratios of Am(III) and Nd(III) with the extractant and DTPA solution either one of which was irradiated with60Co γ-rays or the organic—aqueous mixed phase irradiated under continuous stirring. The irradiation causes an increase of Df and a decrease of the Nd/Am separation factor β, to an especially large extent in the mixed phase system. These effects are due firstly to the radiolytic decomposition of DTPA and secondarily to the formation of MEHPA. The replacement of nitrate with lactate stops the degradation of DTPA and DEHPA resulting in the retardation of increase of Df and a decrease of separation factor. The DEHPA-DTPA-lactic acid system is concluded to sustain absorption of radiation at an absorbed dose up to 200 Wh·I−1 in the partitioning of transplutonium elements in HLW.
TL;DR: The serum samples of the patients suffering from cancer, Down syndrome, and Banti syndrome were analyzed by the neutron activation method and compared with the trace element concentrations observed among the clinically healthy men.
Abstract: An attempt was made to see if there is any correlation between the trace element concentrations in the human blood serum and some specific disease. The serum samples of the patients suffering from cancer, Down syndrome, and Banti syndrome were analyzed by the neutron activation method and compared with the trace element concentrations observed among the clinically healthy men. The cancer patients gave below normal concentrations in Rb, Mn, Fe, Co, Cu, Zn, Al and Se. The Down syndrome patients were found to have similar deficiencies in Cr, Mn, Fe, Co, Zn, Cu and Sb.
TL;DR: In this paper, the change in selectivities by thermal treatment was studied on crystalline (C-SbA) and amorphous (A-SBA) antimonic (V) acids.
Abstract: The change in selectivities by thermal treatment was studied on crystalline (C-SbA) and amorphous (A-SbA) antimonic(V) acids. The equilibrium distribution coefficients (Kd) of Na+ and K+ ions in HNO3 solution showed a maximum on the C-SbA heated at 330 °C. An inverse relationship was noticed between the changes in Kd values and in the lattice constants for the heated C-SbA. A-SbA heated at 20–500°C showed two steps of time dependence of adsorption for Na+, while a maximum for K+. This behavior can be explained in terms of the transformation from amorphous material to C-SbA.
TL;DR: In this paper, radio-tracer experiments have shown that antimony, mercury and zinc interact to form complexes with humic and/or fulvic acids, whose molar masses can be estimated by gel chromatography.
Abstract: Radio-tracer experiments have shown that antimony, mercury and zinc interact to form complexes with humic and/or fulvic acids, whose molar masses can be estimated by gel chromatography. Sb(III) and (V) humates are stable in the pH range 7–11, but are largely dissociated below pH 4; humic acid does not reduce Sb(V) to Sb(III) in solution. Mercury forms a strong complex with humic+fulvic acids. Zinc forms complexes with both humic acids and glycine, and the humic acid complex has similar elution behaviour on dextran gel to a fraction from river water equilibrated with65Zn. At least one other form of zinc, in addition to Zn2+, occurs in this river.
TL;DR: Neutron activation analysis and atomic absorption spectrometry (graphite furnace) methods for the analysis of selenium in human tissue are described in this paper, where the sensitivity (10−30 ng/sample), accuracy and precision are of the same order for both techniques and the choice can only be made on grounds of urgency or convenience.
Abstract: Neutron activation analysis and atomic absorption spectrometry (graphite furnace) methods for the analysis of selenium in human tissue are described. The sensitivity (10–30 ng/sample), accuracy and precision are of the same order for both techniques and the choice can only be made on grounds of urgency or convenience. AAS should be chosen for the analysis of wet tissue or the urgent analysis of small numbers of dry tissue. NAA should be chosen for the analysis of large numbers of dry tissue samples where time is not important. The selenium concentration of human liver is shown to be in the region of 1 to 2 ppm (dry weight). Selenium may be lost from tissue during freeze drying if the samples are not maintained at −35°C.
TL;DR: An improvement in a method for the synthesis of13NO2− from13NO3− with specific activity>30 mCi/mL and radiochemical purity>99% is described.
Abstract: An improvement in a method for the synthesis of13NO 2 − from13NO 3 − with specific activity>30 mCi/mL and radiochemical purity>99% is described.13NO 3 − is produced by the16O(p, α)13N reaction using a recirculating water target and 20 MeV protons.13NO 2 − is synthesized by reduction of13NO 3 − in a cadmium-copper column. Contaminating13NH 4 + is removed by rotatory evaporation at pH>11.0. The synthetic procedure takes less than 20 minutes from collection of irradiated target water to sterilization of the radiopharmaceutical.
TL;DR: An improved method for production of >100 mCi of77Br with the78Se(p, 2n)77Br nuclear reaction and a 4π water-cooled target containing encapsulated metallic78Se or a Pb78Se alloy has been developed.
Abstract: An improved method for production of >100 mCi of77Br with the78Se(p, 2n)77Br nuclear reaction and a 4π water-cooled target containing encapsulated metallic78Se or a Pb78Se alloy has been developed. The77Br was separated with ∼98% radiochemical yield and a radionuclidic purity of 98.9%. The time required to isolate carrier-free77Br free of metallic impurities was less than 4hrs. Isotopically enriched78Se was quantitatively recovered.
TL;DR: In this article, the concentrations of 11 trace and minor elements (Na, Al, S, Cl, Ca, V, Mn, Ni, As, Br, I) have been measured by instrumental neutron activation analysis in a sample of crude oil from Venezuela, and in 7 of its distillates and in the final residue produced in a primary distillation unit.
Abstract: The concentrations of 11 trace and minor elements (Na, Al, S, Cl, Ca, V, Mn, Ni, As, Br, I) have been measured by instrumental neutron activation analysis in a sample of crude oil from Venezuela, and in 7 of its distillates and in the final residue produced in a primary distillation unit. Concentrations range from 0.5 ppb to 2.0%. The elements have been classified in 4 categories on the basis of their distributions among the fractions analyzed. The results on concentrations have also been used to establish elemental balances in the distillation unit studied operating under steady-state conditions. Only S and V have been found to give rise to losses by emission.