Journal of Radioanalytical and Nuclear Chemistry

Published by Akadémiai Kiadó
Online ISSN: 1588-2780
Print ISSN: 0236-5731
The choice of analytical techniques for the solution of real analytical problems is governed not only by the characteristics of the individual methods, but also by the alternatives available. The capabilities of some methods of elemental analysis are considered and compared with those of selected techniques based upon sample irradiation with charged particles.
Positron lifetime and Doppler broadening of the annihilation line measurements were performed in highT c superconducting samples YBa2Cu3Cdx Oy ,x=0, 0.05 and 6.9<y<7, as a function of temperature in the region of 14–300 K. It was found that the positron lifetime and theS parameter values are lower in the Cd doped sample than those in the undoped one. It was also observed that the positron annihilation parameters show similar temperature dependence for the undoped and Cd doped samples. We conclude that the Cd doping in highT c superconductor YBa2Cu3Cdx Oy , 6.9<y<7 fills defects associated with oxygen vacancies probably in oxygen deficient regions which can trap positrons.
Nuclear data of calibration sources used for the determination of efficiency calibration
A 740 GBq 241Am-Be neutron source based prompt gamma-ray activation analysis (PGAA) setup in combination with a typical coaxial n-type HPGe detector (REGe) system was used to analyze light elements like H, B, C, N, etc. The absolute full energy peak (FEP) efficiencies of the shielded REGe detector for irradiation and counting geometries and for sources with different sizes (point, ampoule and cylindrical) were measured in the 0.1–2.5 MeV energy range by utilizing calibrated sources (point, liquid and solid). 4th order polynomials were fitted to the experimental data. Efficiencies in far irradiation and counting geometries are compared.
Neutron Well Coincidence Counting has been explored as a non destructive assay technique for determining the percentage of PuO2 in blended mixture of UO2 and PuO2 powders. The method has been applied to MOX blends having PuO2 content varying from 0.4 to 44% for both thermal and fast reactors. The use of Neutron Well Coincidence Counting technique is validated as a process control step for determining PuO2 content in the fabrication of MOX fuel by comparing it with chemical analysis of sintered pellets. It has been used at Advanced Fuel fabrication Facility, Bhabha Atomic Research Centre, Tarapur during the manufacture of MOX fuel of various types for thermal and fast reactors. KeywordsMOX-PuO2%-NDA-NWCC
A study of the possibility of using half-lives between 0.55 and 873 msec in activation analysis with 14 MeV neutrons is presented here. The cyclic counting method is used: irradiation and detection are repeated several times and counts are memorised during all successive cycles until good final statistics are reached. The theoretical aspect of the cyclic counting method and the influence of neutron pulse shape on the activation results are discussed. The sample is activated and its activity measured in the same geometry: the sample and the scintillation detector are placed close to the target of the neutron generator. An electronic gating system is used to avoid photomultiplier gain fluctuations involved in neutron bombardment. Detection limits are measured for the following elements: Be, B, Al, Ca, As, Zr, In, Tl, Pb, Bi.
Utilization of thermal ionization mass spectrometry as a routine analytical service provided to the Los Alamos National Laboratory Bioassay Program has evolved significantly since its implementation just over three years ago. Converting this unique research tool designed to support nuclear weapons testing to a quasi-production mode for the routine analysis of ~300 urine samples/year for ultra-low levels of plutonium has required resolution of numerous practical issues. These issues include clean-room sample preparation, adequate tracer recovery, customer specified turn-around times, throughput, water and urine blank values, statistical data reduction, and quality control and performance evaluation sample requirements.
In 1997, the Department of Energy, Office of International Health Programs(EH-63) contracted the National Institute of Standards and Technology (NIST)to perform an intercomparison to evaluate state-of-the-art analysis techniquesfor 239Pu in synthetic urine in Bq quantities. Sample preparationwas performed by Yankee Atomic Environmental Laboratory. Five replicate samplesat spike amounts of 3.7, 9.26, 29.6, and 55.6 Bq and a blank amountwere distributed to the participating laboratories in 200 g of synthetic urine.Los Alamos National Laboratory (LANL) participated in the intercomparisonusing thermal ionization mass spectrometry (TIMS). LANL results, system improvements,and future intercomparisons are discussed.
A comparison of an average radiochemical yields of 85 Sr for eluents of various concentration
Activity concentrations in Bq dm -3 for 90 Sr-groundwater sample from NPP A1 (2U is combined uncertainty)
Multiple uses: Radiochemical yields of 85 Sr using 3M TM Empore Sr Rad Disk
Activity concentrations in Bq dm -3 for 90 Sr-groundwater sample from NPP A1 (2U is combined uncertainty)
Multiple uses: Radiochemical yields of 85 Sr using AnaLig Ò Sr-01 (60-100 mesh)
We studied the use of an extraction chromatography for determination of 90Sr in contaminated water samples. The aim of our work was to compare selected products from the point of view of the strontium chemical yields and analysis time. Three commercial products, 3M Empore™ Strontium Rad Disk, AnaLig® Sr-01 gel, Sr®Resin, and two classical methods, liquid–liquid extraction with tributhylphosphate and carbonate co-precipitation, were tested for the separation of 90Sr. The water sample from nuclear power plant A1 Jaslovske Bohunice was used for radiochemical analysis of 90Sr volume activity. Samples were traced with 85Sr to monitor strontium chemical recovery and counted either by Cerenkov counting on TRI CARB 2900 TR liquid scintillation counter or low level alpha–beta proportional counter. KeywordsStrontium separation–Solid phase extraction–3M Empore™ Strontium Rad Disk–AnaLig® Sr-01–Sr®Resin
Analysis of geological materials requires the use of matrix specific reference materials (RMs). Phosphate rocks (PR), the basic ingredient of phosphate fertilizers, are very important in agriculture. A project was undertaken to study the PRs of the Hazara Deposits of Pakistan. Due to the unavailability of phosphate rock reference materials (PR-RMs) with a large number of certified elements, validation of the results was problematic when carrying out elemental analysis of PR samples and their derived products. Therefore a parallel study was performed to determine the composition of three phosphate based RMs; BCR-RM-032 (Natural Moroccan Phosphorite), IAEA-434 (Phosphogypsum) and PRH (a local PR-RM from the Hazara Deposits of Pakistan). Instrumental Neutron Activation Analysis was used for this purpose and more than 30 elements including rare earth elements were determined in the three PR samples. KeywordsInstrumental Neutron Activation Analysis (INAA)–IAEA-434–BCR-RM-032–Phosphate rocks–Reference materials–Hazara deposits
Performance evaluation of our results for Chinese ancient ceramic (Concentrations in mg/kg unless specified)
A proficiency test (PT) exercise was offered by the International Atomic Energy Agency (IAEA) for major, minor and trace elements in Chinese ceramic reference material (IAEA-CU-2006-06). Neutron activation analysis (NAA) laboratory at PINSTECH, Pakistan participated in the exercise and submitted the results for 28 elements. The aim of participation was to develop a suitable methodology for accurate measurement of as many elements as possible in ceramic material using a low power reactor (PARR-2) as this would help future investigation in a project on the authenticity of art objects, for provenance, conservation and management of ancient cultural heritage of the country. After receiving the final report of the PT exercise, a critical review of our data and final scoring of each element is made to check the suitability of our methodology and reliability of the acquired data. Most of the reported results passed different statistical evaluation criterion such as relative bias, z-score and u-scores and ratio of our results and IAEA target values. One element (Yb) falls in the unacceptable range of relative bias and z-scores. Hf and Tb showed slightly high z-scores within the questionable range. Ho, Mo and Sn were determined during this study but their results were not submitted to the IAEA. The confidence of accuracy observed for most of the elements in ceramic material has made it mandatory to report their results as information values. KeywordsCeramic–Inorganic elements–Instrumental neutron activation analysis–Proficiency test–Reference materials (RMs)
An experimental method is described for the synthesis of195mPt-radiolabeled (–)-(R)-2-aminomethylpyrrolidine (1,1-cyclobutanedicarboxylato)-2-platinum (II) (DWA2114R). An amount of 10 mg of 95% enriched194Pt was irradiated for 75 h in the hydraulic conveyer of the KUR at a thermal neutron flux of approximately 8.11013–2.sec–1 and the195mPt-radiolabeled DWA2114R was purified using HPLC. The chemical yield is higher than 65%, its chemical purity is greater than 99.2%, the radiochemical purity is nearly 100%, and the specific activity is 6.7 MBq. mg–1 DWA2114R.
A radiotracer based method for the determination of the rate of expel of a swelling agent from a swelling agent saturated polymer foil induced by a second organic liquid (i.e., blowing agent for foaming of polymers) has been set up and tested. The method was applied to acetone swollen polyetherimide (PEI) foil and 1,1,1-trichloroethane and ethanol (blowing agents) systems. By combining the results of radiotracer measurements with those obtained by measuring foil weights, the amount of the respective blowing agents that replaced acetone in the PEI foil was determined.
Extraction of barium by a nitrobenzene solution of bis-1,2-dicarbollylcobaltate in the presence of 15-crown-5 (15C5, L) has been investigated. The equilibrium data and the typical maxima concerning the dependencies of the Ba distribution ratios on the analytical concentration of 15C5 in the system under study can be explained assuming that the particles HL+, HL2 + and BaL2 2+ are extracted into the nitrobenzene phase. The values of the corresponding extraction and stability constants of the extracted species in nitrobenzene saturated with water have been determined.
The interaction of the clinically used 1,2-dimethyl-3-hydroxypyrid-4-one with trivalent europium Eu(III), was investigated by using potentiometric and spectroscopic methods. The stability constants of the EuLn (3−n)+ complexes determined by spectroscopic and potentiometric measurements were found to be log β11 = 6.5±0.3 and log β12 = 12.0±0.5. However, at pH ≥ 5, hydrolysis of the Eu-L complexes starts, resulting in the formation of needle-type, yellow crystals. The low solubility of the Eu-L complexes in the neutral pH range is disadvantageous with respect to the use of deferiprone as chelating agent for decorporation of trivalent f-elements.
Extraction of microamounts of europium and americium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H+B−) in the presence of 1,2-(diphenylphosphino)ethylene dioxide (DPPEDO, L) has been investigated. The equilibrium data have been explained assuming that the cations HL+, \( {\text{HL}}_{ 2}^{+},\) \( {\text{ML}}_{2}^{3+},\) \( {\text{ML}}_{ 3}^{3+} \) and \( {\text{ML}}_{ 4}^{ 3+ } \) (M3+ = Eu3+, Am3+) are extracted into the organic phase. The values of extraction and stability constants of the species in nitrobenzene saturated with water have been determined. It has been found that the stability constants of the corresponding complexes \( {\text{EuL}}_{n}^{ 3+ } \) and \( {\text{AmL}}_{n}^{ 3+ },\)where n = 2, 3, 4 and L is DPPEDO, in water saturated nitrobenzene are comparable.
A complex of Fe(III) with 1,2 dihydroxy 9, 10, anthraquinone (DHA) has been prepared. The metal ion forms a 13 complex with DHA. The complex is formed due to the dissociation of one proton per ligand bound to the metal ion. The stability constant of the Fe(III) complex is 1.611032. The complex reduces the catalytic flow of electrons from NADH to molecular O2 through NADH dehydrogenase over DHA. The Fe(III) compelx is seen to be an efficient radiosensitizer towards -radiation induced degradation of thymine in a nitrous oxide saturated medium.
Experimental results of positron annihilation experiments in solutions of n-butanol in three diols are compared to those of ultrasonic velocity and absorption. Variations of the annihilation parameters with composition show that the effect of the hydrophobic solute on the original diol structure is rather limited and occurs only in the system where ethylene glycol is the solvent. Subtle similarities were found when compared it to the respective results for similar aqueous systems, suggesting that crystalline-like solvates are forming in ethylene glycol. However, no such evidences were found for the systems where butanediols are the solvents. Ultrasonic investigations do not confirm formation of any specific structures. This is caused, most possibly, by the fact that compressibility of solvates is close to those of the pure components and/or that of unstructured medium (regular solution).
The results of positron annihilation experiments of solutions of n-hexanol in diols are compared to those of ultrasonic velocity and absorption. Variations of the annihilation parameters with composition allow the conclusion that the effect of hydrophobic solute on the original diol structure is limited. There are, however, significant similarities with the results known for aqueous systems, suggesting that clathrate-like solvates are forming in ethylene glycol, the phenomenon called here is a hydrophobic-like solvation. No evidences for it were found for the systems containing butanediols as solvents. Unfortunately, ultrasonic investigations do not confirm the formation of any specific structures, most possibly because the compressibilities of solvates are close to those of the pure components.
Two 1,2,3-triazole anticonvulsants, 1-(4-methylsulfone-phenyl)-5-(4-fluoro-phenyl)-5-[14C]-1,2,3-triazole and 1-(4-sulfonamide-phenyl)-5-(4-fluoro-phenyl)-5-[14C]-1,2,3-triazole, both labeled with carbon-14 in the 5-position were prepared from para-fluoro-benzonitrile-[cyano-14C].
A new and rapid method has been developed for the quantitative extraction of Ru/III/ with 1,2,3-benzotriazole /1,2,3-BT/ into 1-pentanol. The extraction coefficient value of Ru/III/ between 1-pentanol and an aqueous 5% solution of 1,2,3-BT in 2M sodium acetate-acetic acid buffer showed a maximum value of E=46 at pH 4.5. The effect of various other parameters on the extraction coefficient of Ru/III/ such as solvents, anions, cations, etc. have also been studied. The stoichiometry of metal:reagent determined by the method of substoichiometric extraction and slope ratio method was found to be 13. Decontamination factors for many elements in the substoichiometric extraction of Ru/III/ were also evaluated.
The rigid dopamine analogue (+/-) 6,7-ADTN was originally synthesized to probe the geometrical constraints of the dopamine receptor family and [3H] (+/-) 6,7-ADTN was required for receptor binding assay. The radioligands was prepared by means of catalytic tritium dehalogenation of a suitable dibromo precursor and characterized by HPLC and tritium NMR. It has proven very useful as a tool to study dopaminergic receptors.
A novel macroporous silica-based 2,6-bis(5,6-diisobutyl-1,2,4-triazine-3-yl)pyridine (iso-Bu-BTP), a neutral chelating agent having several softatom nitrogen, polymeric composite (iso-Bu-BTP/SiO2-P) was synthesized. It was done through impregnation and immobilization of iso-Bu-BTP molecule into the pores of SiO2-P particles with 40–60 μm of bead diameter and 0.6 μm of mean pore size. The effective impregnation resulted from the intermolecular interaction of iso-Bu-BTP and co-polymer inside the SiO2-P particles by a vacuum sucking technique. To understand the possibility of applying iso-Bu-BTP in the MAREC process developed, the adsorption behavior of a few representative rare earths (REs) such as Ce(III), Nd(III), Gd(III), Dy(III), Er(III), Yb(III), and Y(III) towards iso-Bu-BTP/SiO2-P was investigated at 298 K. The influence of the HNO3 concentration in a wide range of pH 5.52–3.0M and a few chelating agents such as formic acid, citric acid, and diethylenetriaminepentaacetic acid (DTPA) on the adsorption of RE(III) was examined. It was found that in the presence of chelating agent, the adsorption ability of the tested RE(III) towards iso-Bu-BTP/SiO2-P decreased due to two competition reactions of RE(III) with iso-Bu-BTP/SiO2-P and chelating agents. In a 0.01M HNO3 solution containing 1M formic acid or 1M citric acid, light RE(III) showed lower adsorption towards iso-Bu-BTP/SiO2-P than that of the heavy one. This makes the separation of light RE(III) from the heavy one possible. Based on the similarity of minor actinides and heavy RE(III) in chemical properties and the results of column separation experiments, chromatographic partitioning of light RE(III) from a simulated high level liquid waste solution composed of the heavy RE(III) and minor actinides in MAREC process is promising.
Cephalosporanic acids (CEPHAs) such as dihydro-1,4-thiazine derivatives and 2-hydroxyalkyl-1,3-thiazolidine-4-carboxylic-acids, (HOTCAs) are both important biologically active molecules and complexing agents for several metals such as Fe, Zn, Pb, etc. The simplest way for the study of the effect of complex formation upon the biochemistry of these compounds requires radiolabeled complexes. As99mTc radioisotope gives the best opportunity for imaging the in vivo process,99mTc-CEPHAs and HOTCAs were prepared and investigated. It was found that biologically active molecules like CEPHAs and HOTCAs can be labeled with99mTc with good radiochemical yields. In case of one CEPHA compound, low but definite myocardial uptake was observed, while 3 of the HOTCAs showed characteristic renal uptake and wash-out without visualization of any other organs than the urinary tract.
The preparation of99mTc-Sn-complexes with derivatives of (4R)-1,3-thiazolidine-4-carboxylic acid is described. The labeling efficiency of all labeled compounds was checked by paper chromatography, thin layer chromatography and paper electrophoresis. Preliminary results of the biodistribution studies performed in mice are given. The proposed structure of the99mTc-labled monocomplexes is also discussed.
An apparatus has been designed and built up to investigate reactions of accelerated ions with a neutral gas target. It was of great importance to analyze the neutral reaction products. Such reactions and these products played a significant role in the identification of the elements 104 and 105 by ZVARA et al. Preliminary results are reported for the systems Ar++H2 and Kr++CO2, in which neutral reaction products could be identified.
The stable radiolysis products of 1-chlorobutane (1-CB), 1-chlorobutene-2 (1-CB-2), 1-chloropropane (1-CP), 2-chloropropane (2-CP) and 1,3-dichloropropane (1,3-DCP) gamma-irradiated in an oxygen-free atmosphere have been investigated. The pure radiolysis products were separated by preparative gas chromatography and identified by NMR and mass spectroscopy as well as qualitative gas chromatography. The compounds formed were determined by potentiometric analysis and quantitative gas chromatography. From 1-CB we have obtained in the gas phase: HCl, H2, butane; in the liquid phase: 2-chlorobutane, 1,3-dichlorobutane and a mixture of oligomers of the initial compound (dimer and trimer). We have not recorded H2 in 1-CB-2. The main gaseous products of radiolysis of 1-CP are HCl and H2. Radiation yield of isomerization was determined. From 2-CP we have obtained in the gas phase: HCl and H2; in the liquid phase: 2,2-dichloropropane and a mixture of oligomers of the initial compound (dimers and trimers). From 1,3-DCP we have found in the gas phase: HCl and H2; in the liquid phase: 1-CP, 2-CP, 1,2-DCP and oligomers. Preliminary schemes for the formation of stable products are proposed.
A procedure for labeling of a fullerene derivative 1-[N',N'-bis(2-chloroethyl)-4-aminophenyl]-N-methyl-fullereno-C60-[1,9-c]pyrrolidine (C60-C13H18N2Cl2) with 125I is reported. The compound was first iodinated with a large excess of iodine monochloride and then radiolabeled by isotopic exchange with Na125I in a toluene-water two-phase system. The dependence of the radiolabeling yield on the reaction temperature and exchange time was examined. The radiolabeling yield of the compound was as high as 94% after heating for 2 hours at 130 °C.
A thick spherical target (R=25 cm) made of gabbro was irradiated isotropically with 1.6 GeV protons at the Saturne cyclotron at Laboratoire National Saturne (LNS)/CEN Saclay in order to simulate the interaction of galactic cosmic ray (GCR) protons with meteoroids in space. During a 2 weeks irradiation a proton-dose of 1.32 1014 cm–2 was received, which is equivalent to a cosmic-ray exposure age of 1.4 Ma. Production rates were measured by X- and gamma-spectrometry, by low-level counting and by conventional and accelerator mass spectrometry (AMS). Up to now, more than 200 target-product combinations were investigated. Theoretical production rates were derived on the basis of spectra of primary protons, secondary protons and secondary neutrons calculated by Monte Carlo techniques and thin-target cross sections of the underlying nuclear reactions. The model calculations excellently describe the production depth profiles in the artificial meteoroid, if reliable crosss sections are available. The thus validated model calculations allow for the interpretation of cosmogenic nuclide abundances in stony meteorites and lunar samples in terms of their exposure history and of the history of the radiation itself.
Solvent extraction of microamounts of europium and cerium by a nitrobenzene solution of hydrogen dicarbollylcobaltate (H+B−) in the presence of polyethylene glycol PEG 1000 (L) has been investigated. The equilibrium data have been explained assuming that the species H2L2+ and ML3+ (M3+=Eu3+, Ce3+) are extracted into the organic phase. The values of extraction and stability constants of the complexes in nitrobenzene saturated with water have been determined. It was found that the stability constants of the cationic complex species EuL3+ and CeL3+ in water-saturated nitrobenzene are practically the same.
Comparison of the present result with other results for the absolute intensity of the 1001 keV gamma-ray of 234m Pa 
The 1001 keV g-ray emission from 234mPa as an analytical peak has ever increasing importance in direct g-ray spectrometric measurements of 238U content in samples with the development of high pure Ge detectors of larger crystal volumes and higher efficiency. In this study, -ray spectrometric measurement for the determination of the absolute intensity, P, of 1001 keV -rays of 234mPa was carried out using powdered uranium samples and a new experimental value of 0.8610.015% for P of the 1001 keV -ray of 234mPa has been obtained. The present measured value is greater than most of the recent experimental results and the newly recommended value of 0.8350.004% for Pg by 2.5 to 4%. The present result differs from the latest experimental value of 0.920.02% by 7%.
The 100Mo(γ, n) reaction cross-section was experimentally determined at end point bremsstrahlung energy of 10 and 12.5MeV using off-line γ-ray spectrometric technique. It was also found that 100Mo(γ, n) reaction cross-section increases sharply from the end point bremsstrahlung energy of 10MeV to 12.5MeV, which may be because of GDR around the energy region of 12–16MeV. The 100Mo(γ, n) reaction cross-section as a function of photon energy was calculated theoretically using TALYS 1.2 computer code. The flux-weighted average values of 100Mo(γ, n) reaction cross-section for bremsstrahlung having end point energy of 10 and 12.5MeV were also calculated using the experimental and theoretical data of mono-energetic photon. The present experimental 100Mo(γ, n) reaction cross-sections were compared with the bremsstrahlung flux-weighted average values of experimental and theoretical data and found to be in the lower side for 10MeV and in the higher side for 12.5MeV. Keywords 100Mo(γ, n) reaction cross-section– 197Au(γ, n) 196Au flux monitor–Bremsstrahlung end point energy of 10 and 12.5MeV–Off-line γ-ray spectrometric technique–TALYS calculation
More than 50% of the technetium in Hanford 101-SY and 103-SY tank waste is not pertechnetate (TcO4 –). These non-pertechnetate species (TcN) are stable, soluble, reduced complexes of technetium. In order to remediate these waste, it will be necessary to oxidize these species to TcO4 –. For radioanalytical purposes, oxidation requires digestion in Ce(IV)/16M HNO3. Many oxidants are ineffective. Sodium peroxydisulfate, sodium peroxydisulfate/silver(I), and ozone oxidize all of the technetium species to pertechnetate.
Capabilities of 14 MeV neutron activation analysis with a high output generator are evaluated and found to be comparable with conventional activation analysis regarding sensitivity and precision; additional elements are instrumentally accessible at trace levels. Nuclear reactions featuring higher selectivity are listed and their sensitivity is compared to the present state of 14 MeV activation. Quasi-promt activation (T<1 sec) expands the scope of the technique to rapid nondestructive assays of trace species in bulk samples.
Partition coefficient of copper and palladium bis-thiosemi- carbazones.
Radioactivity of eluted ethanol fractions from C 18 at optimized conditions for [ 103 Pd]PTSM.
Due to interesting biological properties of palladium-thiosemicarbazono complexes, production of a 103Pd-labeled anti-cancer complex, i.e., [103Pd]-2-acetylpyridine 4N-methylthiosemicarbazone ([103Pd]-APMTS) was developed. Palladium-103 (T1/2 = 16.96 d) produced via the 103Rh(p,n)103Pd nuclear reaction using natural rhodium target, was separated from the irradiated target material. Proton energy was 18 MeV with 200 mA irradiation for 15 hours (final activity 700 mCi of 103Pd2+, RCY>95%, radionuclidic purity>99%). The final activity was eluted in form of Pd(NH3)2Cl2 in order to react with 2-acetylpyridine-4N-methylthiosemicarbazone to yield [103Pd]-APMTS. Chemical purity of the final product was confirmed to be within the accepted limits by polarography. [103Pd]-APMTS was prepared with a radiochemical yield of more than 80% at room temperature after 3 hours. The labeling reaction was optimized for time, temperature and radioactivity and ligand ratio. A mixture of APMTS and Pd activity in ethanol was heated at 90 °C for 3 hours followed by reverse phase SPE purification using C18 plus Sep-Pak. Radiochemical purity of more than 99% using RTLC and specific activity of about 12500 Ci/mol was obtained. The stability of the tracer was checked in the final product and the presence of human serum at 37 °C up to 3 hours. The partition coefficient of the final complex was determined by octanol : saline buffer distribution.
Solvent extraction of no-carrier-added 103Pd was investigated from irradiated rhodium target with a-furyldioxime in chloroform from diluted hydrochloric acid. Extraction yield was 85.3% for a single extraction from 0.37M HCl and 103Pd purity was better than 99%.
Production cross sections of residues with mass near to that of the target were measured in 12C and 16O induced reactions on Rh at an incident energy of 400 MeV. An ion-exchange method has been developed for the separation of Rh, Pd and Ag nuclides from all other produced activities. Rh and Ag nuclides were separated from elements such as Pd, Ru, and Tc, amongst others, on an AG1-X8 anion exchange resin in 6M HCl. The Ag nuclides were then removed from the effluent using a precipitation technique so that only Rh remained in the final solution. The Pd was afterwards separated from Ru and Tc by eluting it from the resin with 5% ammonia solution. This procedure made it possible to accurately measure production cross sections for 103mRh and 103Pd. Cross sections for the production of various other observed residues are also presented. The results are consistent with an enhanced isobaric yield in the near-target mass region. The radiochemical separation technique is also suitable for the routine production of Pd and Rh nuclides, e.g., 103Pd and 101mRh, in proton-induced reactions on Rh targets
An isotope of element 106, namely263106, detected by its spontaneous fission, has been chemically isolated by thermochromatography of oxochlorides. The last one has been compared with short- and long-lived isotopes of Mo and W. Two chemical species were observed, presumably MO2Cl2 and MOCl4 (M=Mo,W). A kinetic dependence of these two species has been discussed and a chemical form [106]O2Cl2 has been described for the registered atoms of element 106.
For the first time the chemical identification of element 106 was accomplished. The Gas-thermochromatographic experiments with an oxochloride of element 106 are described. Reproducible zones of tracks of fission fragments were observed in the temperature region of 150–250C. The chemical behavior of element 106 oxochloride is similar to that of the tungsten compound.
Feasibility of using fixed bed column of conventional ion exchangers/sorbent and chemical precipitation based processes have been examined for the effective removal of the very low levels of 106Ru activity from NH4NO3 effluent generated during wet processing of rejected sintered depleted uranium fuel pellets. Based on the results, a simple process involving precipitation of cobalt sulphide along with ferric hydroxide was selected and further optimization of process variables was carried out. The optimized process has been found to be highly efficient in reducing 106Ru activity down to extremely low levels. Keywords 106Ru removal–Depleted uranium–ADU–Chemical precipitation–Cobalt sulphide
Ion-exchange behavior of Re and Os as homolgs of Bh and Hs, respectively, has been studied in the sulfuric acid media. The distribution coefficients of 183Re and 185Os as well as of other radionuclides between Dowex-50 and H2SO4 solutions were determined as a function of the acid concentration. It was shown, that cation-exchange column may be used for the separation of Os, Re and W from elements of III group, whereas anion-exchange column for their concentration from diluted sulfuric acid solutions. The 0.05M H2SO4 was used for continuous on-line separation of short-lived Os isotopes produced in the nuclear reactions: nat.Dy(20Ne, xn)Os. Radionuclides of Os, Re and W were strongly sorbed on anion-exchange column only.
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 5 0Cr(n,g)5 1 Cr; s0 = (15.2 ±0.2) barn [cf.:15.8 - 16.0] 5 8Fe(n,g)5 9 Fe; s0 = (1.31 ±0.03) barn [cf.:1.14 - 1.16] 1 0 9Ag(n,g)1 1 0 m Ag;s0 = (3.89 ±0.05) barn [cf.:4.4 - 5.0] \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}
In this work, hydroxyapatite (HAP) was prepared by aqueous precipitation technique and was characterized by using FT-IR to determine its chemical functional groups. A series of batch experiments were carried out to investigate the effect of various environmental factors such as contact time, pH, ionic strength, foreign ions, fulvic acid (FA) and temperature on the sorption behavior of HAP towards radionuclide 109Cd(II). The results indicated that the sorption of 109Cd(II) on HAP was strongly dependent on pH and ionic strength. A positive effect of FA on 109Cd(II) sorption was found at pH <7.0, whereas a negative effect was observed at pH >7.0. The Langmuir, Freundlich and D-R models were used to simulate the sorption isotherms at three different temperatures of 298.15, 323.15 and 343.15K. The thermodynamic parameters (ΔH0, ΔS0 and ΔG0) calculated from the temperature dependent sorption isotherms indicated that the sorption process of 109Cd(II) on HAP was spontaneous and endothermic. At low pH, the sorption of 109Cd(II) was dominated by outer-sphere surface complexation and ion exchange on HAP surfaces, whereas inner-sphere surface complexation was the main sorption mechanism at high pH. From the experimental results, it is possible to conclude that HAP has good potentialities for cost-effective treatments of 109Cd(II)-contaminated wastewaters. Keywords 109Cd(II)–Hydroxyapatite–pH–Fulvic acid–Thermodynamic data
Quantitative determination of ppb-order 10B was carried out in a small number of cultured tumor cells by particle tracks by the 10B(n,)7Li reactions using solid state nuclear track detector (SSNTD) for boron neutron capture therapy research. The detection limit of 10B concentration in tumor cells is less than 110-3 ppm under our experimental conditions which permits the quantitative determination of 10B in a small number of boronated tumor cells (105/ml = ca. 0.1 mg). Boron quantities in tumor cells determined were well compatible with the tumor cell killing effects of boron neutron capture therapy.
Advanced chemical treatment processes such as aqueous separation techniques can be used to separate the reusable materials from used nuclear fuel, reducing the radiotoxicity and storage time of the remaining waste. The degradation of chemicals in these processes has been studied utilizing gamma radiation. However, radiolytic degradation by internal alpha emitters has not been as widely investigated due to the difficulty of finding appropriate internal sources. This work presents results using a method to produce alpha particles in situ in aqueous and organic solvents representative of liquid–liquid extraction systems. The method is based on the widely studied 10B(n,α)7Li reaction which has previously been studied in aqueous solutions. Neutrons were supplied from the UCI TRIGA® nuclear reactor. Comparisons were also made to gamma radiation from a 137Cs source. We report that the method is useful for inducing high linear energy transfer (LET) doses in aqueous and organic solutions. We used the classic iron sulfate-based Fricke dosimeter for dosimetry in aqueous solutions and methyl red (2-[(4-dimethylaminophenyl)diazenyl]benzoic acid) dissolved in n-dodecane for organic solvents. High LET doses in both aqueous and organic solvents are well described and a simple linear relationship was found based on the neutron flux and total boron concentration. We have established, using spectroscopic determination, that methyl red degrades in a linear fashion with absorbed dose up to 80kGy and G-values for the methyl red degradation in n-dodecane were found to be 4.66×10−4μmol/J for external 137Cs gamma radiation and 3.0×10−5μmol/J for 10B(n,α)7Li induced high LET radiation. KeywordsHigh LET radiolysis–Organic phase radiolysis–Organic dosimeter–Radiation damage in nuclear separation processes–Methyl red degradation–Neutron induced radiolysis
Characteristics of optical transitions in Am atoms
IS and HFS constants for Am isotopes, kex = 6054
Characteristics of 241Am and 24SAm nuclei
The hyperfine structure and isotope shift of8S7/210P9/2 atomic transition in241Am and243Am was measured with high-resolution by laser fluorescent spectroscopy method. The results concern nuclear moments and charge radii. We notice that the hyperfine structure for the actinide atoms are rather high compared with other elements. This offers ample scope for obtaining information about higher nuclear moments than Q and .
The synthesis of11C-acetate has been achieved via carbonation of methyl magnesium bromide with11C-labelled carbon dioxide. Using this procedure, 7.4 GBq /200 mCi/ of11CO2 produced by the14 N/P,/11C nuclear reaction, was converted, within 20 min into11C-acetate with an activity higher than 2.22 GBq /60 mCi/. Chemical and biologic quality control shows that the product is pure, sterile, and pyrogen-free and therefore suitable for human use. Handling considerable amounts of activity has led us to automate the11C-acetate synthesis. The different parts of the system-programmable controller, sensors, automatic neutralization system-are described in detail.
The retention of different radio-ions on columns of eleven ionic precipitates from different acid media was studied, in view of possible applications for radiochemical separations. The results of about 2,000 adsorption experiments, carried out in a standardized way, are presented schematically in periodic tables.
While there is a lot of information on the elemental content of food for nutritional and pollution studies, the analysis of fruits has received little attention. We have investigated 11 commonly eaten fruits for their trace and minor element constituents by neutron activations including thermal and epithermal neutron activation analysis. Our results revealed that both blueberries and strawberries had the most of top two highest elemental concentrations followed by raspberries, oranges and mango. Bananas, grapes, plums, apples, pears, and cherries had the fewest or none of the most elevated elemental concentrations. KeywordsNeutron activation analysis–Trace elements–Fruit
We have irradiated 30 elements with 11 MeV protons and we present here: (1) The specific activities for the main radioisotopes produced by (p, n) or (p, α) reactions (on main γ rays except the 511 keV). (2) The main γ energies of these radioisotopes (at ±0.3 keV) when they have not been accurately measured previously. (3) The limits of detection or the lowest amounts measured in samples of Al, Ag or Co. From these preliminary results it can be deduced that 11 MeV protons offer new possibilities in the field of activation analysis.
Top-cited authors
Marina Frontasyeva
  • Joint Institute for Nuclear Research
Eiliv Steinnes
  • Norwegian University of Science and Technology
M. C. Freitas
  • Technical University of Lisbon
Octavian Sima
  • University of Bucharest
Constantin Dovlete