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A novel and rapid method to determine 90Sr activity in seawater by proportional counter has been developed. Precipitation of 90Sr and radiochemical separation were investigated. 90Sr was precipitated in the form of oxalate to remove the dominant salts present in seawater and then radiochemical separation was performed by using Sr-resin. The chemical recovery of 90Sr (75–95%) was determined gravimetrically using a stable primary Sr2+ solution. The minimum detectable activity (MDA) of 90Sr was determined to be 0.025 Bq L−1 for 1 L seawater sample for 2 h counting time using ultra-low background proportional counters. The validation of the method has been performed by using the samples from the IAEA-RML-2021 and IAEA-RML-2019 proficiency tests organized by International Atomic Energy Agency (IAEA).ı [ABSTRACT FROM AUTHOR]

Abstract Introduction The radiochemical purity (RCP) of technetium-99m labelled radiopharmaceuticals (RP) is important to ensure optimal scintigraphic image quality. In low-income settings, it may not be possible to use compendial analytical methods or expensive equipment for radiochemical purity analysis. All radiochemical analysis methods should however be validated against compendial or otherwise proven methods. To ensure the efficacy of RP prepared at Yaoundé General Hospital (YGH) Cameroon, this study cross-validated a cost-effective routine chromatographic method using a simple survey meter technique. A GMP-compliant method used at the University Medical Center Groningen (UMCG), the Netherlands was used as the comparator. Methods Sestamibi, HMDP and DMSA kits currently used at YGH were reconstituted at UMCG with about 2000 MBq of freshly eluted sodium pertechnetate as described by the manufacturer, and spiked with eluate of the same generator to obtain a range of impurity concentrations. Samples of technetium-99m RP were spotted on 1 × 10 cm iTLC-SG strips and developed in appropriate mobile phases. Each strip was first scanned on the chromatogram-scanner used at the UMCG (standard method), and immediately thereafter the strip was cut in two pieces and radioactivity from each portion was counted with a small survey meter from YGH. The percentage RCP for each TLC strip was calculated using both counting methods. Internationally recommended validation parameters and acceptance criteria were used. Student’s paired t-test or ANOVA were used with ‘no significant difference’ designated at a 95% confidence-interval (P ≥ 0.05). Linearity of the survey meter was determined for Tc-99m. Readings obtained with the survey meter were also plotted against the scanner results. Results and discussion The proposed method proved to be accurate (CV of mean RCP 0.05). LOD and LOQ were determined for the survey meter. Specificity depends on chemical separation. As we were validating the suitability of a method to quantify radioactivity, specificity was not included in the validation parameters. Conclusion The proposed method compared well with the standard method and is suitable as a reliable low cost method for limited resource settings.

Background: Radium-226 is a radioactive element, with a very long half-life of 1600 years, producing radon gas. According to the United States Environmental Protection Agency, radon gas is the second most important factor causing lung cancer. Objectives: The purpose of this study was to separate 226Ra from the soil of high background radiation area by a radiochemical method for using in radon calibration chamber. Methods: 226Ra can be used in standard calibration chambers for calibration of radon detection systems. For this purpose, radiochemical method was used to extract radium from the soil with a high concentration of 226Ra. Four soil samples used in this study were selected from high background radiation areas of Ramsar, north of Iran. Equal amounts of samples were gathered from each region and ground. The specific activity of radium-226 was measured with HPGe detector. The highest specific activity of radium-226 (44.8 Bq/g) belonged to Talesh-Mahaleh. After radiochemical separation of 226Ra, the specific activity of extracted radium crystals was measured with the HPGe detector. Results: According to the results, the specific activity of 226Ra was found to be 94.97 Bq/g. Therefore, the specific activity of 226Ra was 2.12 times greater in the extracted crystals than in the original soil samples. Conclusion: The results indicate that using the radiochemical method proposed in this study, 226Ra can be extracted with an efficiency of 42%

Introduction: The radiochemical purity (RCP) of technetium-99m labelled radiopharmaceuticals (RP) is important to ensure optimal scintigraphic image quality. In low-income settings, it may not be possible to use compendial analytical methods or expensive equipment for radiochemical purity analysis. All radiochemical analysis methods should however be validated against compendial or otherwise proven methods. To ensure the efficacy of RP prepared at Yaoundé General Hospital (YGH) Cameroon, this study cross-validated a cost-effective routine chromatographic method using a simple survey meter technique. A GMP-compliant method used at the University Medical Center Groningen (UMCG), the Netherlands was used as the comparator. Methods: Sestamibi, HMDP and DMSA kits currently used at YGH were reconstituted at UMCG with about 2000 MBq of freshly eluted sodium pertechnetate as described by the manufacturer, and spiked with eluate of the same generator to obtain a range of impurity concentrations. Samples of technetium-99m RP were spotted on 1 × 10 cm iTLC-SG strips and developed in appropriate mobile phases. Each strip was first scanned on the chromatogram-scanner used at the UMCG (standard method), and immediately thereafter the strip was cut in two pieces and radioactivity from each portion was counted with a small survey meter from YGH. The percentage RCP for each TLC strip was calculated using both counting methods. Internationally recommended validation parameters and acceptance criteria were used. Student's paired t-test or ANOVA were used with 'no significant difference' designated at a 95% confidence-interval (P ≥ 0.05). Linearity of the survey meter was determined for Tc-99m. Readings obtained with the survey meter were also plotted against the scanner results. Results and discussion: The proposed method proved to be accurate (CV of mean RCP < 2), precise (RSD < 2%), linear (slope close to 1, r2 ≥ 0.99) within the RCP range of approximately 80% to 100%, and robust (P > 0.05). LOD and LOQ were determined for the survey meter. Specificity depends on chemical separation. As we were validating the suitability of a method to quantify radioactivity, specificity was not included in the validation parameters. Conclusion: The proposed method compared well with the standard method and is suitable as a reliable low cost method for limited resource settings. [ABSTRACT FROM AUTHOR]

The proposed and validated method for determination of Sr content in environmental samples (water, soil and plant) is based on the radiochemical analytical separation of Y from the sample and measuring its activity after the establishment of radioactive equilibrium with Sr. Validation is the confirmation by examination and provision of objective evidence that they meet the individual requirements stipulated for a specific use. Validation of method was done based on the blank samples for water by adding Sr known activity and using reference materials of soil (IAEA-326) and plant (IAEA-330). Content of Sr in environmental samples was determined by α/β low level proportional counter. The accuracy and the precision of the applied method are confirmed and the method is validated and can be used for determination of Sr in environmental samples. On the other hand, participations in interlaboratory comparisons are confirmed that the adequacy of the validated method is ensured. [ABSTRACT FROM AUTHOR]

Abstract: A radiochemical method has been adapted to determine 59Ni and 63Ni in samples of radioactive wastes from the water cleanup system of the IEA-R1 nuclear research reactor. The process includes extraction chromatographic resin with dimethylglyoxime (DMG) as a functional group. Activity concentrations of 59Ni and 63Ni were measured, respectively, by X-ray spectrometry and liquid scintillation counting, whereas the chemical yield was determined by ICP-OES. The average ratio of measured activity concentrations of 63Ni and 59Ni agree well with theory. [Copyright &y& Elsevier]

This study aimed to chemically and radiologically characterize the water resources influenced by a phosphogypsum stack in Imbituba, SC, Brazil and to identify the annual intake by ingestion. Surface water was collected at six points downstream of the phosphogypsum stack. Subsurface water samples were collected from a piezometer in the stack area. These samples were analyzed using a radiochemical method to determine the natural radionuclide content and an inductively coupled plasma optical emission spectrometry to determine the concentration of selected metals. The concentrations of radionuclides were also compared with current standards. The radionuclide concentrations in the surface waters samples were lower or similar to those found in other studies. The effective dose resulting from water ingestion is below the recommended reference levels for drinking water. Samples collected exhibited no increase in radioactivity, under the influence of phosphogypsum stacks. [ABSTRACT FROM AUTHOR]

Abstract: A procedure for the determination of 210Pb, and alpha-emitting radioisotopes of uranium, thorium, and radium from the same aliquot of a sample has been proposed. The key step consisted in the recovery of Pb(II) and Ra by precipitation of insoluble Pb(NO3)2, the uranium and thorium radioisotopes remaining in solution. Afterwards, the fractions were handled by specific, well consolidated procedures. Lead-210 was determined by the LSC technique while the uranium, thorium, and radium radioisotopes were measured with silicon alpha-spectrometers. The procedure was applied to a reference sample and several environmental samples obtaining satisfactory results. [Copyright &y& Elsevier]

A radiochemical method for the determination of 210Pb in various types of samples was validated. An extraction chromatographic material Eichrom SrResin® was used for Pb separation. From the resin, Pb was eluted with 6 M HCl. The method was tested for water, inorganic and organic matrices. As a main result of the study, activity concentrations of 210Pb in 19 food samples of the main Czech food-basket items were determined. Results ranged from 0.03 ± 0.01 Bq kg−1 to 1.54 ± 0.40 Bq kg−1, fresh mass. [ABSTRACT FROM AUTHOR]

The Venice Lagoon is connected to the Adriatic Sea by three inlets, with an average daily water inflow of 345*106 m3. Due to the diversion of the major rivers out of the lagoon (done in the past centuries), the sediment supply from the drainage basin is now very low when compared to the amount of sediment exchanged at the inlets (<1%). The limited sediment supply and the combined action of natural and anthropic pressures (e.g. waves, ships, fishing activities, dredging for navigation purposes) have caused in the last few decades a significant erosion of mudflats and salt-marshes. In order to investigate the history and the characteristics of the above phenomenon, with particular regard to the most recent years and the future trend, a wide radiochemical survey has been carried out in the whole lagoon, including the characterisation of the suspended particulate matter entering and leaving the lagoon in different tidal and meteorological conditions, with the aim of obtaining an indirect estimate of the sediment mass balance of the lagoon. The proposed radiochemical methodology, which is based on concentration measurements of airborne radionuclides in suspended particulate matter, appears to be an useful alternative to direct methods (e.g. bathymetric campaigns in the lagoon or mass fluxes measurements of the suspended particulate materials exchanged at the inlets). The results obtained, which show a complex sedimentary situation, highlight the erosion acting in some central and southern lagoon areas but recognise also the present accumulation phase coming into view in the northern lagoon. [Copyright &y& Elsevier]

The yields of 7Be and 10Be produced by bremsstrahlung having a maximum energy (E0) of 200 MeV in natCu, natAg and 197Au targets were investigated by the AMS technique at MALT of the University of Tokyo. It was found that the yields at E0=200 MeV were much lower than those at E0⩾250 MeV, obtained in our previous works. A change in the yields of the fragmentation component in the target-mass dependence was observed at E0=200 MeV when compared with those at E0⩾250 MeV. However, the ratios of the fragmentation yield of 10Be to that of 7Be remained unchanged throughout the concerned E0. [Copyright &y& Elsevier]

The cumulative yields of various short and relative long-lived fission products within the mass range of 80–115 and 123–157 have been measured in the epi-cadmium neutron induced fission of 99.9997 atom % 238U, by using an off-line γ-ray spectrometric technique. The mass chain yields were obtained from the cumulative yields by applying the charge distribution correction. The present and earlier data in the 238U(n, f) reaction was compared with the similar data of 232Th(n, f) reaction. In the 38U(n, f) reaction, the yields around the mass range 134–138 and their complementary are higher than the other fission products, which indicate the favorable standard I asymmetric mode of fission. On the other hand, in the 232Th(n, f) reaction, the yields around 139–144 and their complementary are higher than the other fission products, which indicate the favorable standard II asymmetric mode of fission. •Yields of fission products were measured in the epi-cadmium neutron induced fission of 238U. • Radiochemical and an off-line γ-ray spectrometry was used for the measurement. • Mass yields were obtained from the cumulative yield by using the charge distribution correction. • Mass distribution in the 238U(n, f) reaction are important to explain the nuclear fission mechanism. [ABSTRACT FROM AUTHOR]

Abstract: In a previous paper the authors proposed a sequential method for the determination of isotopes of uranium, thorium, radium, and lead from environmental samples using alpha-particle spectrometry and LSC techniques. Although the radiochemical yields were suitable when the assays were performed on synthetic samples, application to real environmental samples caused a major decrease in the radiochemical yield, especially for uranium in inorganic samples (soils). A modification of the procedure is described that overcomes this drawback. [Copyright &y& Elsevier]