Determination of137Cs,90Sr and fallout Pu in the volcanic soil of Korea

The cumulative depositions of¹³⁷Cs,⁹⁰Sr and fallout Pu in the volcanic ash soil of Korea were determined. The average accumulated depositions of¹³⁷Cs,⁹⁰Sr and fallout Pu in the volcanic soil were much higher than those in other forest sites of Korea. From depth profiles, it was found that¹³⁷Cs,⁹⁰Sr and^239,240Pu in the volcanic soil are more mobile than those in other forest sites of Korea, and that the downward movement of⁹⁰Sr is faster than¹³⁷Cs and^239,240Pu. A significant correlation was found between the concentration of¹³⁷Cs and those of⁹⁰Sr and^239,240Pu. The activity ratios of²³⁸Pu/^239,240Pu and²⁴¹Pu/^239,240Pu in soils are close to those observed in the cumulative deposit from the global fallout of nuclear weapon testings.     

Determination of90Sr in soil and sediment using lithium-borate fusion and extraction chromatography

A rapid and reliable method for determination of⁹⁰Sr in soil and sediment has been developed. The method is based on lithium-borate fusion and extraction chromatography with a Sr-resin. The samples can be dissolved and separated for Sr in approximately 5 hours of which the fusion and dissolution requires 20 minutes. The method has been applied to four reference materials, two soils and two sediments, and the results agree well with the recommended values. The mean recovery of Sr was 71%.     

Determination of 90Sr in Portuguese foodstuffs

The Nuclear and Technological Institute (ITN) has the legal responsibility to carry out the environmental radiological monitoring at a national level. This survey was planned to provide relevant information on radioactivity levels in different components of the ecosystem. In what concerns the terrestrial environment the evaluation of the ⁹⁰Sr activity concentrations in foodstuffs has been performed using a method based on the separation of ⁹⁰Sr by extraction chromatography and beta determination by liquid scintillation counting (LSC) technique. The trials were carried out using 7 g of ash samples and 3 g of commercial Sr-resin (Eichrom). Validation trials were also performed using ⁹⁰Sr spiked samples. The chemical yields were determined by gravimetric method, after the addition of stable strontium to the foodstuffs. The ⁹⁰Sr activity concentrations in complete meals, meat and vegetables were determined after ⁹⁰Y ingrowths in the region 12–862 keV, using the Tri-Carb 3170 TR/SL scintillation counter in normal mode and a counting time of 120 min. The results obtained were low and of the same order of magnitude of those reported by other European countries.     

Radiochemical analysis of90Sr in milk,soil and plants by solvent extraction

A universal and fast method of⁹⁰Sr determination in environmental matrices (raw and dried milk, plants, soils) has been elaborated. Solvent extraction method of daughter⁹⁰Y by tributyl phosphate was used. The method of strontium determination is compatible with determination of other transuranic elements (americium, plutonium) and there is no need to check the chemical yield of strontium.     

Determination of90Sr by thin layer radiochromatography

A simple method for the determination of⁹⁰Sr by using thin layer chromatography on silica gel or cellulose pretreated with calcium oxalate is proposed. In these conditions a complete separation between strontium and its daughter yttrium is obtained. Radioactivity of separated elements was measured by a linear multiscanner analyzer and the results were computer processed to obtain the activity of⁹⁰Sr. The method has been applied to samples of water and milk subjected to a very simple extraction procedure. Under the experimental conditions used, the detection limit is about 25 mBq of deposited radioactivity, which corresponds to about 6 Bq/l.     

Determination of 90Sr in urine samples and 89Sr/90Sr in water samples by chemical separation and Cherenkov counting with LSC system

Journal of Radioanalytical and Nuclear Chemistry - In order to determine radiostrontium with a satisfactory chemical yield, calculated by an external standard, and a low level of MDC a...     

Determination of 90Sr in sea shell: environmental monitoring

Journal of Radioanalytical and Nuclear Chemistry - This work presents a fast and efficient radiochemical method for the determination of strontium-90 in the presence of high concentration of...     

Determination of bromoxynil and ioxynil residues in cereals and soil by GC-ITD

Chromatographia - Bromoxynil and ioxynil have been determined inplants and soil by gas chromatography. These herbicides are extracted from soil samples with methylene chloride at acidic pH. Plant...     

Beta-spectroscopic separation of90Sr,90Y and89Sr with a scintillation detector

A -spectroscopic method for measurement of the isotope ratios and absolute activities of⁹⁰Sr,⁹⁰Y and⁸⁹Sr with an organic scintillator is described and tested. The correction factors for absorption in the sample and the detector window are calculated. The method can be used for rapid estimation of ratios and absolute activities of pure -emitters after a nuclear accident.Supported in part by the International Atomic Energy Agency, RC5633 and the National Fund for Scientific Research (Bulgaria).     

Determination of 90Sr and 210Pb in freshwater fish in Austria

A method for the determination of ⁹⁰Sr and ²¹⁰Pb in freshwater fish was developed. The determinations were conducted within a project on behalf of the Federal Ministry of Health. The aim of this project was to get an overview of the activity concentrations of natural and artificial radionuclides in freshwater fish in different lakes in Austria. For sampling the Neusiedler See in Burgenland, two lakes in Styria the Grundlsee and the Toplitz See, and the Zeller See in Salzburg were chosen. Chub (Leuciscus cephalus), pike (Esox lucius), perch (Perca fluviatilis), carp (Cyprinus carpio), catfish (Silurus glanis), pike-perch (Sander lucioperca) and burbot (Lota lota) were analysed. The samples were analysed using strontium specific extraction columns (Eichrom Industries Inc., TrisKem International) and liquid scintillation counting. In the edible parts of the fish samples (no fishbone) values of the activity concentration for ²¹⁰Pb varied between 0.009 ± 0.003 and 0.16 ± 0.04 Bq kg _freshweight ^?1 and for ⁹⁰Sr between 0.010 ± 0.002 and 0.11 ± 0.02 Bq kg _freshweight ^?1 . In this paper the method for the determination of ⁹⁰Sr and ²¹⁰Pb is described and the results are discussed.     

Determination of 90Sr in different matrices via ion-exchange chromatography and LSC

Journal of Radioanalytical and Nuclear Chemistry - A cation-exchange chromatographic method was utilized to isolate strontium. The interference of recovery yield, calcium and magnesium, and the...     

Transfer behaviors of 90Sr and 137Cs from soil to grass to cow milk under natural conditions in Central Italy and their exposure risk

Journal of Radioanalytical and Nuclear Chemistry - Based on the newly-developed techniques, the transfer behaviors of 90Sr and 137Cs under natural conditions were studied. The concentrations of...     

Determination of 90 Sr in milk by solvent extraction of 90Y (author's transl)

In order to replace the conventional method using violent fuming nitric acid, a new method for the determination of 90 Sr in milk has been developed by using the solvent extraction with bis (2-ethylhexyl) phosphoric acid (HDEHP). The daughter nuclide 90Y in a radiochemical equilibrium with its parent 90Sr was extracted with 2:1 HDEHP-toluene from the acid solution (1M HCL) of milk ash sample prepared by dry-ashing. After stripping with 8M HCL, 90Y, together with stable yttrium added as carrier, was precipated as oxalate to prepare beta-counting source. The radiochemical purity was confirmed by decay curve. The decontamination of strontium was checked by applying non-dispersive fluorescence X-ray analysis using 133Ba as irradiating source. Bone samples of cow were also analyzed by the same method and the results were compared with those obtained by other methods. The duplicate crosschecking analyses of finely ground bone samples were carried out to examine the effectiveness of this method. This simple new method was found to be very effective for the routine analysis of 90Sr in these samples.     

Combined procedure for the determination of90Sr,241Am and Pu radionuclides in soil samples

A combined procedure for sequential determination of low level activity concentrations of⁹⁰Sr,²⁴¹Am and Pu radionuclides is described. The analysis of -emitters is performed by isotope dilution -spectrometry using²⁴²Pu or²³⁶Pu and²⁴³Am tracers. Strontium-90 is analyzed by liquid scintillation counting using the double energetic windows method. The method combines the well established, procedure for Pu analysis based on anion exchange, the powerful and selective method for Sr isolation based on extraction chromatography using Sr-Spec resin and finally it includes the application of the TRU-Spec column for separation and purification of the Am fraction. The radiochemical procedure was tested using IAEA reference and intercomparison materials. Major parameters of the procedure as well as advantages and drawbacks are discussed in detail.     

Determination of90Sr and137Cs in mushrooms following the Chernobyl fallout

After the Chernobyl accident high concentrations of radionuclides were found in Sweden in mushrooms and the contents of⁹⁰Sr and¹³⁷Cs were measured. The level of⁹⁰Sr was generally low and, in proportion to¹³⁷Cs, 2–3 orders of magnitude lower than in the fallut. The contents of¹³⁷Cs varied among species and extreme local variations occurred. The ratio¹³⁴Cs/¹³⁷Cs diverged from other biological samples leading to the conclusion that old fallout was involved in the uptake.     

On a Pure Instrumental Method of 90Sr Determination in Bone Samples

An attempt is presented for the measurement of ⁹⁰Sr in real animal bone samples using gamma-ray spectrometry only with germanium detector. Gamma-ray spectra of bone samples are de-convoluted and the residue bremsstrahlung effect from ⁹⁰Sr-⁹⁰Y beta-radiation is observed. The validation of the proposed method was done by standard ⁹⁰Sr determination including radiochemical separation and liquid scintillation spectrometry (LSS). The Pearson correlation factor obtained between the activity determined by LSS and the proposed instrumental method was 0.57, with the achieved efficiency of 0.12%. Possible improvements of the method are suggested.     

Determination of 90Sr in radioactive concentrate from Nuclear Power Plant Mochovce

This paper describes the use of molecular recognition technology product AnaLig^®Sr-01 gel from IBC Advanced Technologies, Inc. to effectively and selectively pre-concentrate, separate and recover strontium from evaporator concentrate samples from Nuclear Power Plant Mochovce which belongs to the most difficult matrices to analyze. The method is suitable for analyzing highly contaminated samples of radioactive waste in a relatively short time and with high decontamination factors. Activity of ⁹⁰Sr was measured using Cherenkov counting on TRI CARB 2900 TR liquid scintillation counter.     

Determination of 90Sr in environmental samples using solid phase extraction chromatography

The p-tert-butyl calix[4]arene thiophenol derivative was successfully synthesized with reflux condition and was characterized by FT-IR and ¹H-NMR. This work mainly adopted the method of controlling variables. The results showed that the optimum pH value, temperature and extraction time were respectively 4.5, 25 °C and 90 min. By calculating the data of the enthalpy change and gibbs free energy, indicating that the process of reaction was an exothermic and spontaneous process, and it demonstrated a close agreement with pseudo-second-order kinetic model. It is also found that the coexisting cations on the extraction of uranium had greater influence.

     

Analytical Methods for the Determination of 90Sr and 239,240Pu in Environmental Samples

Artificial long-lived radionuclides such as ⁹⁰Sr and ^239,240Pu have been long released into the environment by human nuclear activities, which have a profound impact on the ecological environment. It is of great significance to monitor the concentration of these radionuclides for environmental safety. This paper summarizes and critically discusses the separation and measurement methods for ultra-trace determination of ⁹⁰Sr, ²³⁹Pu, and ²⁴⁰Pu in the environment. After selecting the measurement method, it is necessary to consider the decontamination of the interference from matrix elements and the key elements, and this involves the choice of the separation method. Measurement methods include both radiometric methods and non-radiometric methods. Radiometric methods, including alpha spectroscopy, liquid scintillation spectrometry, etc., are commonly used methods for measuring ^239+240Pu and ⁹⁰Sr. Mass spectrometry, as the representative of non-radiometric measurement methods, has been regarded as the most promising analytical method due to its high absolute sensitivity, low detection limit, and relatively short sample-analysis time. Through the comparison of various measurement methods, the future development trend of radionuclide measurement is prospected in this review. The fully automatic and rapid analysis method is a highlight. The new mass spectrometer with ultra-high sensitivity shows strong analytical capabilities for extremely low concentrations of ⁹⁰Sr, ²³⁹Pu, and ²⁴⁰Pu, and it is expected to develop determination methods with higher sensitivity and lower detection limit.