Showing papers in "Journal of Radioanalytical and Nuclear Chemistry in 1984"
TL;DR: In this article, the Radracer method has been used for investigation of the adsorption and desorption of traces of radium on kaolinite and montmorillonite under conditions similar to those prevailing in waste and surface waters.
Abstract: Radiotracer method has been used for investigation of the adsorption and desorption of traces of radium on kaolinite and montmorillonite under conditions similar to those prevailing in waste and surface waters. It has been found that adsorption depends on the pH and ionic strength of the solution, and the character of these dependences is different for kaolinite and montmorillonite. Sulfates at concentration 60 mg·l−1 have negligible effect on the adsorption. Montmorillonite represents better adsorbent for radium than kaolinite, but both minerals may significantly affect the form and migration of radium in surface waters, if present as (major) components of freshwater sediments. Radium can be quantitatively desorbed by 1M HCl from kaolinite but not from montmorillonite. The desorption by 0.1M NaCl is generally lower and depends on the pH during the preliminary adsorption. Mechanisms of radium adsorption on both minerals and the character of the adsorption sites are discussed.
55 citations
TL;DR: In this article, the adsorption of cesium on manganese dioxide from aqueous solutions has been studied in relation to pertinent variables such as shaking time, pH, composition of aaqueous solutions, mass of adsorbent (10 mg-1 g) and concentration of adorbate (10−6−5·10−3 M) using a radiotracer technique.
Abstract: The adsorption of cesium on manganese dioxide from aqueous solutions has been studied in relation to pertinent variables such as shaking time, pH, composition of aqueous solutions, mass of adsorbent (10 mg–1 g) and concentration of adsorbate (10−6–5·10−3 M), using a radiotracer technique. The influence of various anions and cations on cesium adsorption was examined. The distribution coefficient of a variety of other elements was determined under similar conditions. The adsorption of cesium obeys a Freundlich-type isotherm over the entire concentration range investigated, whereas the Langmuir-type isotherm is followed only at moderate concentrations.
45 citations
TL;DR: In this paper, the effect of the defect centers in calcites by electron spin resonance spectroscopy (ESR/ESR) was investigated and the consequence of these interferences were discussed.
Abstract: Envestigations on the behaviour of the defect centres in calcites by means of electron spin resonance spectroscopy /ESR/ have shown the occurrence of important interferences, which may have an impact on age determinations. These effects are produced by humic acids, sunlight exposure, grinding, instability of paramagnetic centres, measurement conditions, and possible pretreatment of the sample. The consequence of these interferences are discussed.
39 citations
TL;DR: In this article, an analytical method for129I and127I in various environmental samples is described. The method consists of sample digestion by alkali fusion, iodine separation by solvent extraction, neutron irradiation, radiochemical purification of iodine and gamma-spectrometry.
Abstract: An analytical method for129I and127I in various environmental samples is described. The method consists of sample digestion by alkali fusion, iodine separation by solvent extraction, neutron irradiation, radiochemical purification of iodine and gamma-spectrometry. The detection limit of129I and the129I/127I ratio are 1·10−3 pCi and 1·10−9, respectively. The range of the129I/127I ratios obtained in the environmental samples collected from the Tokaimura area in Japan was between 1·10−9 and 7.9·10−6. The highest ratio was observed in pine needles followed by rain water, soil, swamp water and algae.
34 citations
TL;DR: In this paper, the k0-standardization method combines general versatility (with respect to irradiation and counting conditions) with good accuracy, while keeping the experimental work as simple as possible.
Abstract: USGS BCR-1 and G-2, NBS 1633a Coal Fly-Ash and a 7-element synthetic standard for biological material have been analysed in this work by reactor NAA, using the k0-standardization method. The analyses were performed independently in the analytical laboratories of the Institute for Nuclear Sciences (INW), Gent, and the Central Research Institute for Physics (KFKI), Budapest. This procedure allowed not only a comparison with the specified data or with other published values, but enabled a check of the consistency of our own results obtained in largely different experimental circumstances. As concluded the k0-standardization method combines general versatility (with respect to irradiation and counting conditions) with good accuracy, while keeping the experimental work as simple as possible. Since the k0 method is a computer-oriented technique, a FORTRAN IV program was designed and applied on a VAX 11/780 machine.
33 citations
TL;DR: In this paper, a new variant of a technique for determining ion mobilities by means of horizontal zone electrophoresis in free solutions is developed, where the setup circuit and results of measuring limiting mobilities of 131I-and 160Tb3+ are given.
Abstract: A new variant of a technique for determining ion mobilities by means of horizontal zone electrophoresis in free solutions is developed. Setup circuit is presented. Some details of experiment and results of measuring limiting mobilities of131I-and160Tb3+ are given. On these examples the reproductibility was checked.
26 citations
TL;DR: In this article, the surface contamination and depth profiles of hydrogen-implanted silicon, amorphous silicon layers and silicon oxide films produced by anodic oxidation were measured by the resonant nuclear reactions1H(19F, αγ)16O and 1H(15N,αγ)12C.
Abstract: Hydrogen surface contamination and depth profiles can be measured by the resonant nuclear reactions1H(19F, αγ)16O and1H(15N, αγ)12C. The method was applied to study hydrogen-implanted silicon, amorphous silicon layers and silicon oxide films produced by anodic oxidation.
26 citations
TL;DR: In this paper, a new internal standard method for activation analysis has been developed, characterized by that a suitable element present originally in the sample is used as an internal standard and the comparative standard is prepared by applying the standard addition method to the duplicated sample.
Abstract: A new internal standard method for activation analysis has been developed. This method is characterized by that a suitable element present originally in the sample is used as an internal standard and the comparative standard is prepared by applying the standard addition method to the duplicated sample. When a sample under examination contains Wag of trace element A to be determined together with a known amount of element B which is usable as an internal standard, and when the comparative standard is prepared by adding W
a
*
g of accurately known small amount of the element A to the duplicated sample, even if the sample and comparative standard are irradiated separately by particles with different fluxes, Wa can be determined, easily by using the following equation: Wa=W
a
*
/[(A
R
*
/AR)-1] Where AR and A
R
*
are counting ratios of gamma-rays emitted by two radioactive nuclides produced from the element A and B in the sample and comparative standard, respectively. Neither correction of the inhomogeneities of flux between the sample and comparative standard, nor that of, the self-shielding effects are necessary for the present method. The usefulness of the method was examined through the determination of Co, Ni, Rb and Sr in pepperbush by means of photon activation, and the precision and accuracy of the method were proved to be valid.
24 citations
TL;DR: In this article, the trace element composition of human fingernails was analyzed using the Proton Particle-Induced X-ray Emission (Proton PIXE) method.
Abstract: The method of proton particle-induced X-ray emission (proton PIXE) has been employed to study the trace element composition of human fingernails. The samples were colleted from 51 subjects randomly selected from a working community of about 500 adults and they were analyzed by the thick-target external beam technique of the PIXE method. The samples were exposed to the proton beam as 1-mm thick pellets and irradiated with 2 MeV protons having 20 nA beam intensity. For 40 μC irradiations, the concentration of fourteen elements, K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Rb, Sr and Pb, were measured by comparison with a calibration obtained from the NBS orchard leaf standard (SRM 1571). Some anomalous cases have been revealed from this study and they are attributed to environmental factors. The frequency distributions of the elements are presented and the results compared with available data.
23 citations
TL;DR: In this paper, a non-destructive activation analysis of cobalt specimens by proton beam bombardment has been carried out on 18 elements for the purpose of quantitative analysis, and the results showed that the purification effects of anion exchange, electrolytic extraction, and floating zone refining have been examined.
Abstract: Nondestructive activation analysis by proton beam bombardment has been applied to cobalt specimens. Thick target yields were measured on 18 elements for the purpose of quantitative analysis. In order to detect precisely the radionuclides with different half-lives, gamma-ray spectrometry was repeated three times after different cooling times of 1, 15 and 250 hrs from the finish of bombardment for 1 hrby 10.4 MeV proton beam. It was found that Ti, Cr, Fe, Ni, Cu, Zn, Ga, Ge, As, Se, Zr, Nb, Mo, Cd, Sn, Sb, and Te of the order of ppm or less could be detected accurately. Using the proton activation analysis developed, the purification effects of anion exchange, electrolytic extraction, and floating zone-refining have been examined. It was confirmed that the concentrations of the impurity elements contained in the starting material decreased stepwise upon the application of each purification method.
22 citations
TL;DR: In this paper, the concept of effective resonance energy (EEE) was elucidated with respect to dimensioning, accuracy and usefulness, and the EEE parameter was introduced as a parameter in the absolute (e.g. k 0-) standardization methodology of (n, γ) activation analysis.
Abstract: The concept of the effective resonance energy
$$\bar E_r $$
, formerly introduced as a parameter in the absolute (e.g. k0-) standardization methodology of (n, γ) activation analysis, is elucidated with respect to dimensioning, accuracy and usefulness.
TL;DR: In this paper, a new generalized advantage factor which reflects a practical improvement of detection limits in ENAA is proposed, and the determination of practical advantage factors is also given to the different irradiation channels available for the experiment in a given reactor, or even in several accessible reactors.
Abstract: Various theoretical and practical aspects of epithermal neutron activation analysis (ENAA) and fast-neutron-induced reaction interferences in conventional instrumental thermal neutron activation analysis (TNAA) have been considered. A new generalized advantage factor which reflects a practical improvement of detection limits in ENAA is proposed. In the determination of practical advantage factors, consideration is also given to the different irradiation channels available for the experiment in a given reactor, or even in several accessible reactors. Fast neutron reaction interference factors are tabulated for both ENAA and TNAA and examples are given of specific interferences in TNAA for some biological and geological matrices.
TL;DR: In this paper, the effect of the nonideal epithermal flux distribution on the analysis result is considered and the resonance integral to 2200 ms−1 cross-section ratio (QO) is calculated for 11 isotopes.
Abstract: When making use of some single comparator or absolute standardization methods in reactor neutron and in epicadmium neutron activation analysis, the knowledge of the effective resonance energy (\(\bar E_r \)) is essential to correct for the effect of the nonideal epithermal flux distribution on the analysis result.\(\bar E_r \) can be calculated from neutron resonance data, but when these are incomplete, not accurate or even not known at all, experimental determination should be considered. Such a method, providing both\(\bar E_r \) and the resonance integral to 2200 ms−1 cross-section ratio (QO), is described in this paper. Results are given for 11 isotopes.
TL;DR: Isotopic abundance values for 50Cr,58Fe and109Ag and the absolute gamma-intensities for 51Cr,59Fe and110mAg were evaluated as discussed by the authors, together with experimental k0-determinations (i.e. from the activation method) made it possible to calculate the following 2200 m.s−1 cross-sections, which considerably deviate from the hitherto generally published ones.
Abstract: Isotopic abundance values for50Cr,58Fe and109Ag and the absolute gamma-intensities for51Cr,59Fe and110mAg were evaluated. These evaluated data, together with experimental k0-determinations (i.e. from the “activation method”), made it possible to calculate the following 2200 m.s−1 cross-sections, which considerably deviate from the hitherto generally published ones [between brackets]:
$$\begin{gathered} {}^{5 0}Cr(n,\gamma )^{5 1} Cr; \sigma _0 = (15.2 \pm 0.2) barn [cf.:15.8 - 16.0] \hfill \\ {}^{5 8}Fe(n,\gamma )^{5 9} Fe; \sigma _0 = (1.31 \pm 0.03) barn [cf.:1.14 - 1.16] \hfill \\ {}^{1 0 9}Ag(n,\gamma )^{1 1 0 m} Ag;\sigma _0 = (3.89 \pm 0.05) barn [cf.:4.4 - 5.0] \hfill \\ \end{gathered} $$
TL;DR: In this article, the authors proposed a method to date a sample without determination of annual dose rate, when two ESR centers of different stability are present, assuming that the centers are independent and decay according to a first order process and that their concentration is far from saturation.
Abstract: It should, in principle, be possible to date a sample without determination of annual dose rate, when two ESR centers of different stability are present. The method assumes that the centers are independent and decay according to a first order process and that their concentration is far from saturation. The model is presented with emphasis on its inherent difficulties.
TL;DR: In this paper, the stacked foil method was used to produce carrier-free 96Tc and 111In in order to obtain radioactivities for tracer uses, which were obtained by the irradiation at 5 μA current for 2 hrs.
Abstract: In order to produce routinely carrier-free96Tc and111In, their simultaneous production was examined by means of the stacked foil method. Both niobium and silver foils were arranged on the target holder so as the desired nuclear reactions took place effectively. Simultaneous irradiation of the target with 35 MeV α-particles produced effectively111In and96Tc by the109Ag(α, 2n)111In and93Nb(α, n)96Tc reactions, respectively. Sufficient amounts of radioactivities for tracer uses are obtained by the irradiation at 5 μA current for 2 hrs. In addition, carrier-free96TcO4
− in a perchloric acid solution could be prepared by the combined use of precipitation and anion-exchange methods. Separation of carrier-free111In from the silver matrix was done by means of solvent extraction using acetylacetone as a chelating agent.
TL;DR: The γ-ray induced decomposition of several inorganic nitrates at an absorbed dose of {5 Mrads} has been studied in this paper, where the inner cation is affected by the outer cation and depends mainly on its valency and ionic size.
Abstract: The γ-ray induced decomposition of several inorganic nitrates CsNO3, TlNO3, Mg/NO3/2.6H2O, Ca/NO3/2.4H2O, Hg/NO3/2, Hg/NO3/2.2H2O, Pb/NO3/2 and Al/NO3/3.9H2O has been studied at an absorbed dose of {5 Mrads. G/NO
2
−
/ is affected by the outer cation and depends mainly on its valency and ionic size. G/NO
2
−
/ for hydrated mercuric nitrate is always higher as compared to that for the anhydrous mercuric nitrate at various doses. Water of crystallization might provide extra factors to facilitate the decomposition of the hydrated nitrate compared to that for the anhydrous salts. In most cases G/NO
2
−
/ decreases exponentially with dose but in cases of CsNO3, Mg/NO3/2.6H2O and Al/NO3/3.9H2O it varies linearly.
TL;DR: In this paper, the synergistic effect of neutral bidentate ligands, such as 1,10-phenanthroline(phen), 2,9-dimethyl-1,10-, dmp, and 2,2′-bipyridine(bpy), has been studied in the extraction of Mn(II) labeled with54Mn, using 2-thenoyl-trifluoroacetone(HTTA) in various organic solvents.
Abstract: Synergistic effect of neutral bidentate ligands, L, such as 1,10-phenanthroline(phen), 2,9-dimethyl-1,10-phenanthroline(dmp), and 2,2′-bipyridine(bpy), and of neutral unidentate ligands TBP and TOPO have been studied in the extraction of Mn(II) labeled with54Mn, using 2-thenoyl-trifluoroacetone(HTTA) in various organic solvents. The following factors play an important role in the synergistic extraction involving bidentate ligands; two-phase partition of bidentate ligands, their protonation and complex formation with Mn(II) in the aqueous phase. The mixed ligand complex, Mn(TTA)2L, is formed in all bidentate ligand systems. The adduct formation constant (αS,1) decreases in the following order; phen (lg αS,1=12.64) > dmp(11.32)> · bpy(8.54) in the cyclohexane system. This order is ascribed to the bacisity and the steric effect of the bidentate ligands. Organic solvents influence both the adduct formation and the partition of the ligands, and αS,1 decreases in the order cyclohexane>carbon tetrachloride>chlorobenzen ∼= benzene>chloroform.
TL;DR: In this article, a γ-ray source of ≈300 keV was used in order to excite the fluorescent K-radiation of the heavy elements which is only weakly absorbed in the walls of metal tubes.
Abstract: A γ-ray source of ≈300 keV was used in order to excite the fluorescent K-radiation of the heavy elements which is only weakly absorbed in the walls of metal tubes. Thus, uranium can be determined quantitatively in solutions within tubes in the concentration range form 5 mg/l to 100 g/l. The influences of the energy and the activity of the radiation source, the geometrical arrangement, the thickness of the wall and the wall material have been investigated.
TL;DR: A marked increase in the concentration of238U in rain was observed at Fayetteville (36 °N, 94 °W), Arkansas, after the 18 May 1980 eruption of Mount St Helens as discussed by the authors.
Abstract: A marked increase in the concentration of238U in rain was observed at Fayetteville (36 °N, 94 °W), Arkansas, after the 18 May 1980 eruption of Mount St Helens The fallout of natural uranium observed during the summer months of 1980 can be attributed to the 18 May 1980 events, which ejected an amount of ash material on the order of 4 km3 or about 8·1015 grams into the atmosphere234U and235U were found to be highly enriched relative to238U in several rain samples collected at Fayetteville, Arkansas, prior to the volcanic eruption The anomalous uranium seems to have originated from the Soviet satellite Cosmos-954, which fell over Canada, on 24 January 1978 The effect of the 25th Chinese nuclear test, which occurred on 16 October 1980, on the concentrations of uranium isotopes in rain appears to have been insignificant
TL;DR: A 3.7 MeV external proton beam was employed to produce X-rays in Pinus rigida mill /pitch pine/ intra-annual growth rings and several elements were quantitatively determined as mentioned in this paper.
Abstract: A 3.7 MeV external proton beam was employed to produce X-rays in Pinus rigida Mill /pitch pine/ intra-annual growth rings and several elements were quantitatively determined. The PIXE experimental set-up, rapid sample preparation methods, and some interesting observations are discussed. In addition, statistical analysis of the tree-ring element concentrations revealed that Cl, K and Ca were slightly translocated whereas the other elements detected were not. The concentrations of several elements in the rings were negatively correlated with annual stream water pH which reflected precipitation pH.
TL;DR: In this article, a new approach for making column type 99mTc generators based on neutron irradiation of metallic molybdates and direct elution eliminating intermediate chemical processing steps was reported.
Abstract: The authors report here a new approach for making99mTc generators based on neutron irradiation of metallic molybdates and direct elution eliminating intermediate chemical processing steps. This approach tested using zirconium molybdate was found to yield99mTc with good yield and purity. This seems to be the simplest way of making column type99mTc generator even using low flux reactors and merits further detailed evaluation.
TL;DR: A radiochemical procedure has been developed for the simultaneous determinations of alpha-emitting isotopes of uranium and plutonium in bovine bone as mentioned in this paper, which was successfully used for human bone.
Abstract: A radiochemical procedure has been developed for the simultaneous determinations of alpha-emitting isotopes of uranium and plutonium in bovine bone. The radiochemical recoveries ranged from 61 to 93% with a mean of 80±10% for uranium and 57 to 88% with a mean of 75±11% for plutonium. The method was successfully used for human bone.
TL;DR: In this article, the Mossbauer spectra indicated that iron on the silica support existed either as Fe/O/ in the Rh−Fe alloy or as Fe3+ in RH−Fe metal cluster compounds.
Abstract: Silica supported Rh−Fe catalysts were characterized by means of in situ57Fe Mossbauer spectroscopy. The Mossbauer spectra indicated that iron on the silica support existed either as Fe/O/ in the Rh−Fe alloy or as Fe3+ in Rh−Fe metal cluster compounds. The (Fe3+/Fe/O/) ratio and Mossbauer parameters were found to depend on the (Fe/Rh) atomic ratio in the catalysts. Such dependence corresponded to the change of catalytic properties of the supported Rh−Fe catalyst with the varying (Fe/Rh) ratio.
TL;DR: Adsorption behavior of trace elements, In(III, Sn(IV), Sb(V) and Te(IV) on activated carbon and graphite powder was studied in this article.
Abstract: Adsorption behaviour of trace elements, In(III), Sn(IV), Sb(V) and Te(IV) on activated carbon and graphite powder was studied. Adsorption characteristics of the ions enabled the separation of In(III)−Sn(IV), Sn(IV)−Sb(V) and Sb(V)−Te(IV) pairs. Applications to practical separation, milking of113mIn from113Sn, removal of tin impurity from119Sb, and milking of119Sb from119mTe, are presented.
TL;DR: A study of the inorganic chemical composition of 10 different Nigerian medicinal plant species, using the technique of instrumental neutron activation analysis /INAA/, resulted in the determination of the concentrations of 18 major, minor, and trace elements: Al, Ba, Br, Ca, Cl, Eu, Fe, Ga, K, La, Mn, Na, Sb, Sc, Si, Sm, V, and Zn.
Abstract: This study of the inorganic chemical composition of 10 different Nigerian medicinal plant species, using the technique of instrumental neutron activation analysis /INAA/, resulted in the determination of the concentrations of 18 major, minor, and trace elements: Al, Ba, Br, Ca, Cl, Eu, Fe, Ga, K, La, Mn, Na, Sb, Sc, Si, Sm, V, and Zn. The parts of the plants used were roots, leaves, and bark. The NBS SRM 1571 Orchard Leaves was also analyzed to assess the accuracy of the procedures used.
TL;DR: In this paper, the effect of various doses of gamma radiation on the ion exchange capacity, distribution coefficient values, elution behaviour, pH titration and infrared spectra of some thermally stable inorganic ion exchangers has been studied systematically.
Abstract: Effect of various doses of gamma radiation on the ion-exchange capacity, distribution coefficient values, elution behaviour, pH titration and infrared spectra of some thermally stable inorganic ion exchangers has been studied systematically. No change has been observed in the ion-exchange capacity, elution behaviour and the infrared spectra of the materials irradiated up to a total dose of 3·108 rad, while, a change has been observed in their pH-titration and distribution behaviour.
TL;DR: In this paper, the results for Co (1.3 ppb) and Cu (2.0 ppb), compared with those obtained by previous workers, showed that the presence of Hg is the first reported value for this element in the Dead Sea.
Abstract: Cobalt, copper and mercury were determined in Dead Sea surface water, sampled in February 1979 after the complete overturn of the lake. Co, Cu and Hg have been coprecipitated with lead-APDC and detected by X-ray spectrometry following neutron activation. The beta ray interference in the determination of Co by X-ray spectrometry has been eliminated by magnetic deflection. The results for Co (1.3 ppb) and Cu (2.0 ppb) were compared with those obtained by previous workers. The concentration of Hg (1.2 ppb) is the first reported value for this element in the Dead Sea.
TL;DR: In this paper, the mobility of oxidized astatine in solutions H(Na)ClO4 (μ=0.4 M) − 1·10−4M K2Cr2O7 has been measured at 25°C in the interval 0.032±0.005.
Abstract: The mobility of oxidized astatine in solutions H(Na)ClO4 (μ=0.4 M) − 1·10−4M K2Cr2O7 has been measured at 25°C in the interval 0.63≤pH≤1.68. Under these conditions astatine migrates to the cathode only. The speed of the migration depends upon the concentration of hydrogen ions in solution: pH 1.68 Uc = 1.17 · 10-4 cm2 V-1 s-1 pH 0.63 Uc = 2.67 · 10-4 cm2 V-1 s-1
The effect agrees with the opinion that the singly charged cation of astatine formed in acidic solutions is a strong aquacomplex [(H2O)xAt]+ (x=1–2) (protonated hypoastatic acid). Deprotonation constant of this cation is Kdp=0.032±0.005. Specific properties of the astatine cation are given. They can be explained, probably, through the peculiarities of its structure.
TL;DR: In this article, a portable apparatus was developed for the rapid collection, separation and counting of krypton-85 in the environmental air samples, which consists of a molecular sieve trap for the elimination of H2O and CO2, a charcoal trap for collection of Krypton, a chromatographic column for the isolation of KD in the air sample and a vial for the dissolution of KD in the scintillation solution.
Abstract: A portable apparatus was developed for the rapid collection, separation and counting of krypton-85 in the environmental air samples. The apparatus consists of a molecular sieve trap for the elimination of H2O and CO2, a charcoal trap for the collection of krypton, a chromatographic column for the isolation of krypton in the air sample and a vial for the dissolution of krypton in the scintillation solution. With this apparatus, krypton can be collected from half a cubic meter of air with 94% recovery in about 3 hrs. The measurements of krypton-85 have been done several times in Fukuoka area between the periods Jan. 30, 1981 and Dec. 9, 1981. And then, the krypton-85 concentration was found to be approximately 21 pCi/m3 air. The results were compared with those obtained by foregin investigators.