Volume 106, Issue 10

New determination of the stability constants related to the Pu(VI)/carbonate chemical system has been obtained by coupling capillary electrophoresis and ICP-MS at the ionic strength of 0.202 m in NaClO 4 and for a temperature of 25°C. The following values have been obtained: log10βPuO2CO3=8.12±0.02,${\log _{10}}{\beta _{{\rm{Pu}}{{\rm{O}}_2}{\rm{C}}{{\rm{O}}_3}}} = 8.12 \pm 0.02,$log10βPuO2(CO3)22−=13.96±0.04,${\log _{10}}{\beta _{{\rm{Pu}}{{\rm{O}}_2}({\rm{C}}{{\rm{O}}_3})_2^{2 - }}} = 13.96 \pm 0.04,$ and log10βPuO2(CO3)34−=18.10±0.03.${\log _{10}}{\beta _{{\rm{Pu}}{{\rm{O}}_2}({\rm{C}}{{\rm{O}}_3})_3^{4 - }}} = 18.10 \pm 0.03.$ Based on the values selected by AEN/OECD, the interaction coefficients have been re-evaluated as follows: εPuO2CO3=0.02±0.21,${\varepsilon _{{\rm{Pu}}{{\rm{O}}_2}{\rm{C}}{{\rm{O}}_3}}} = 0.02 \pm 0.21,$εPuO2(CO3)22−,Na+=0.12±0.08,${\varepsilon _{{\rm{Pu}}{{\rm{O}}_2}({\rm{C}}{{\rm{O}}_3})_2^{2 - },{\rm{N}}{{\rm{a}}^ + }}} = 0.12 \pm 0.08,$εPuO2(CO3)34−,Na+=0.14±0.18 kg⋅mol−1.${\varepsilon _{{\rm{Pu}}{{\rm{O}}_2}({\rm{C}}{{\rm{O}}_3})_3^{4 - },{\rm{N}}{{\rm{a}}^ + }}} = 0.14 \pm 0.18{\rm{ kg}} \cdot {\rm{mo}}{{\rm{l}}^{ - 1}}.$

A methodology for sequential separation of uranium (U) and plutonium (Pu) followed by their estimation, using extractive liquid scintillation spectrometry was standardized for matrices like soil, fish and sediment. Various parameters for selective and efficient extraction and separation of Pu and U in the presence of interfering matrix elements with HDEHP bis(2-ethylhexy1) phosphoric acid as an extracting agent were investigated. Quenching effect of the various extracting reagents on resolution of α spectrum of analytes and reduction in these interferences is discussed in the current study. Standardized procedure gave about 91% of extraction of spiked Pu into the organic phase. Performance of the method was tested by separating and estimating U and Pu in International Atomic Agency (IAEA) certified reference materials like soil/sediment/fish.

Radium-228 ( 228 Ra) and Radium-226 ( 226 Ra) isotopes in drinking water are significant from the aspect of radiation protection and human health. In this paper, the three most common preconcentration methods, i.e.coprecipitation, absorption and evaporation, were reviewed with emphasis on routinely measurement techniques. The reviewed measurement techniques include low background γ -spectrometry, α -spectrometry and liquid scintillation counting. The γ -spectrometry technique is the good selection, when the maximum sensitivity is considered. The Environmental Protection Agency guideline has provided the maximum concentration level 0.74 Bq/L for 226 Ra and 228 Ra. Also, the World Health Organization guideline limit is 1 Bq/L and 0.1 Bq/L for 226 Ra and 228 Ra, respectively.

Potassium bismuthate rods was synthesized in a form of elongated rods in non-aqueous methanol medium. The material morphology and structure were investigated using energy dispersive spectroscopy, scanning electron microscopy, and X-ray diffraction. The effects of annealing temperature on the material morphology and structure were investigated. Sorption kinetic study and ionic selectivity was investigated using batch technique. The sorption of Ce 3+ on potassium bismuthate was found to be Ce 3+ cation’s ionic state selective process. Results showed that the chemical sorption of Ce 3+ ionic state in KBiO 3 follows the reduction of Bi 5+ to Bi 2− as a result of the formation of cerium bismuthide (Ce23+Bi2−O2).$({\rm{Ce}}_2^{3 + }{\rm{B}}{{\rm{i}}^{2 - }}{{\rm{O}}_2}).$ The suggested chemo-sorption mechanism includes equilibration parallel processes of the released K + to form K 2 CeO 2 and Bi 2 O 3 that consumes the original material. The sorption kinetic has two different orders depending on contact time, isotherms fits adequately with Freundlich model and Dubinin-Radushkevich model. The material is considered a candidate for lanthanides radioactivity removal from aqueous media for radioactive waste disposal processes.

The present work has been oriented to prepare radioiodinated olmesartan for a potential cardiac imaging. Olmesartan has been labeled using 125 I or 131 I with N-bromosuccinimide (NBS) as an oxidizing agent. Many factors like amount of N-bromosuccinimide, amount of substrate, pH, reaction temperature and reaction time, have been systematically studied to optimize high yield of [ 125 I]iodoolmesartan. The biological distribution indicates the suitability of [ 125 I]iodoolmesartan as a novel tracer to image heart.

Sildenfil a vasodilating agent is a selective inhibitor of cyclic guanosine monophosphate – specific phosphodiesterase type 5 which is used for the treatment of male erectile dysfunction and pulmonary arterial hypertension. We presented a detailed approach for the synthesis of [ 2 H 3 ]sildenafil, [ 2 H 8 ]sildenafil and N- desmethyl [ 2 H 8 ]sildenafil. By using the approach we successfully synthesized [ 2 H 3 ]sildenafil, [ 2 H 8 ]sildenafil and N -desmethyl [ 2 H 8 ]sildenafil with good isotopic abundance.

In this work, the structure properties and mass attenuation coefficient of MgO nanoparticles were studied before and after gamma irradiation. The as-synthesized samples of MgO nanoparticles by sol–gel method were analyzed by XRD which suggested the double phase; cubic and hexagonal structures of the material. Crystal defects produced in the cubic and hexagonal lattice were studied before and after exposure to 20 kGy gamma irradiation in order to investigate the changes in the structure properties and mass attenuation coefficients of MgO nanoparticles. XRD data of gamma-irradiated and non-irradiated MgO nanoparticles show that the crystal size of MgO nanoparticles increases after radiation exposure. SEM images after irradiation indicated significant changes in the morphology. The UV-Visible absorption spectra of the nanoparticles were taken and the results of optical band gap of the MgO nanoparticles before and after irradiation show that the value of band gap has changed slightly due to gamma irradiation. The results of comparing experimental values of mass attenuation coefficient for non-irradiated MgO nanoparticles with theoretical values of mass attenuation coefficient for MgO microparticles calculated using the NIST XCOM show that the mass attenuation coefficient not only depends on the effective atomic number but also depends on the size of the particles. Also, it is observed that the mass attenuation coefficient of MgO nanoparticles decreases after the irradiation which shows that by increasing the size of the nanoparticles, the mass attenuation coefficient decreases. It could be because the cross-section of photon interaction with materials depends on the surface to volume ratio of nanoparticles. The experimental results also show that the linear and mass attenuation coefficient of MgO nanoparticles decrease with increasing the photon energy.

The values of mass attenuation coefficient, the effective atomic number and the electron density of barite-doped, limonite-doped, serpentine-doped and undoped lithium borate glasses were obtained not only from experimental study using the narrow beam transmission method for 81, 121, 244, 276, 344, 383, 444 and 778 keV gamma energies with Hp-Ge detector, but also therotical work by WinXCom software (1 keV–10 5 MeV). From the obtained results, all glasses type mass attenuation coefficient values tend to decrease under the condition of increasing energy by means of varied interaction mechanism in different energy regions. In addition, the effect of chemical composition on shielding properties was also investigated. It is inferred that doping element with high atomic number improves the gamma rays shielding properties of system. Among the investigated samples, barite-doped lithium borate glasses have highest value of mass attenuation, which makes barite-doped samples good candidates for artificial radiation application where visual detection is especially required.