Determination Of Strontium Research Articles

Rapid determination of strontium-90 in seawater with proportional counters

Rapid determination of strontium-90 in seawater with proportional counters

An overview of automated flow systems for total and isotopic analysis of strontium and yttrium in samples of environmental interest

Due to the different uses of radioactivity during the last decades, there has been an increase in the concentration of natural and artificial radionuclides in the environment. This, along with some accidents with a high affect public opinion (for example, Chernobyl and Fukushima), have led to the growth and establishment of environmental radioactivity monitoring programs. Currently, trends in legislation and research are focused on the development of accurate, precise, reliable and fast analytical methods with low limits of detection (LOD) for radionuclides determination, such as strontium and yttrium, in environmental samples. In this paper, two comprehensive reviews and four automated analytical systems for total and isotopic determination of yttrium and strontium are presented. The developed methods have been applied in the analysis of environmental samples with low concentrations of these analytes. These methodologies have been automated by exploiting flow analysis techniques, such as multi-syringe flow injection analysis (MSFIA), Sequential injection analysis (SIA) and laboratory-on-valve (LOV) systems, achieving a minimal handling and low consumption of samples and reagents, a significant reduction in waste generation and a high frequency of analysis. In the developed methodologies, some spectrometric methods such as ICP-OES and ICP-MS have been implemented as detection techniques instead of radiometric detectors obtaining a fully automated, low-cost and fast yttrium and strontium determinations.

THE RELEVANCE OF THE STUDY OF THE PRIBREZHNY VOLCANIC COMPLEX IN THE CONTEXT OF THE HISTORY INVESTIGATIONS OF SOUTH KAMCHATKA

The present paper contains a review of publications, geological maps and reports on the study of the Pribrezhny volcanic complex of South Kamchatka. The Pribrezhny volcanic complex is comprised of a number of closeset volcanic massifs stretching chain-like along the narrow coastline of the Beregovoy ridge from the Avacha Bay to the Vestnik Bay. The relevance of the work is related to the necessity of revising the geodynamic history of formation of the study area which stems from emergence of some fragmentary, contradictory information about magmatic complexes of South Kamchatka. The paper presents the data on magmatic rocks penetrated in the coastal cliffs of South Kamchatka. Consideration is being given to their formation conditions in the context of a once-popular theory of geosynclines and in that of plate tectonics. Based on the review, several open research problems are formulated concerning the undetermined propagation limits of the Pribrezhny volcanic complex and unknown time intervals of its formation, and the lack of mineralogical and isotopic-geochemical studies of magmatic rocks. A separate research problem is the formation of transitional zone between the continental margin of Kamchatka and the Kuril Island Arc. The paper shows the relevance of the study of the Pribrezhny volcanic complex of South Kamchatka and proposes possible solutions to the research problems. A detailed mapping of the junction zone of Pribrezhny volcanic complex of South Kamchatka and the Kronotsky terrain near the Malko-Petropavlovsk zone of transverse dislocations will make it possible to refine the age and kinematics of their relationship. Determination of rare elements and strontium, neodymium and lead isotopes will provide a possibility to clarify the nature of magmatism as compared to heterochronous volcanic series of South Kamchatka. The data obtained will be needed to study magmogeneration conditions for acid volcanism of South Kamchatka and monogenic volcanism of the Malko-Petropavlovsk zone of transverse dislocations. The paleomagnetic studies, along with dating of rock absolute age, will help to reconstruct the paleolatitude of formation of the Pribrezhny volcanic complex and to restore the geodynamic evolution of formation of South Kamchatka.

High-precision Sr and Nd isotope measurements using a dynamic zoom lens-equipped thermal ionisation mass spectrometer

Techniques for the determination of radiogenic strontium (87Sr/86Sr) and neodymium (143Nd/144Nd) isotope ratios by Thermal Ionisation Mass Spectrometry (TIMS) are presented in this study. We have developed a 5 lines acquisition routine for both elements, taking advantage of the 16 Faraday cups available on the Nu Instruments TIMS in conjunction with an efficient zoom lens system. This allows increased flexibility regarding the number of lines in a multidynamic acquisition routine whilst maintaining optimal peak alignment and peak shape for every measurement line despite the fact that the detectors are not movable. The long-term reproducibility obtained for our Sr (NBS 987) and Nd (Rennes-Ames) standard solutions gives a (87Sr/86Sr)multidyn of 0.7102467 ± 0.0000043 (6.0 ppm, 2 s.d., n = 38) and a (143Nd/144Nd)multidyn of 0.5119537 ± 0.0000022 (4.2 ppm, 2 s.d., n = 31), respectively. We also report (87Sr/86Sr)multidyn and (143Nd/144Nd)multidyn for a set of terrestrial rock standards (including 5 basalts (BCR-2, BHVO-2, BIR-1, Be-N and BR-24), one rhyolite (RGM-1) and one andesite (AGV-2)) with the same, or greater, level of precision as for the pure standards solutions. This level of precision is 2 to 3 times better than the literature data for Sr isotope ratios, and comparable to the latest high precision data reported for Nd isotope ratios. This is the first paper reporting such high precisions for radiogenic Sr and Nd data generated using a TIMS from Nu Instruments. Significant statementHigh precision Sr and Nd isotopic measurements are of key importance in the field of Earth Sciences because they are powerful tools to trace sources of materials and to date them. Here, we report the first high-precision data for 87Sr/86Sr and 143Nd/144Nd (external error of 5–6 ppm for Sr and 4–5 ppm for Nd) measured using a Nu Instruments TIMS. Such precisions will open new opportunities in fields such as geochemistry, geochronology, cosmochemistry, archaeology or forensics.

Estimation of radionuclides global fallout levels in the soils of CIS and eastern Europe territory

This study is devoted to the estimation of radionuclides global fallout levels in the soils of Commonwealth of Independent States (CIS) and Eastern Europe territory as a result of nuclear explosions. 58 standard soil samples were used, which were selected in different soil and climatic areas of the territory of CIS and Eastern Europe in 1978–2018. All samples were measured by gamma spectrometry. Determination of plutonium isotopes and strontium was performed according to the method of the joint determination of these radionuclides from one sample. IN the samples considered in this work, the content of 60Co, 154Eu, 155Eu was below the detection limits, which were 0.4; 1.0 and 1.0, respectively. Natural radionuclides analysis results indicated that the obtained samples are typical soil samples without its abnormal contents. The content of 137Cs, 90Sr, 239+240Pu in a 20 cm soil layer due to global fallout is (3.9 ± 1.7), (2.2 ± 0.8), (0.18 ± 0.08) Bq/kg respectively, which considering the distribution of these radionuclides by depth and average soil density is (1.2 ± 0.5) kBq/m2 for 137Cs, (0.42 ± 0.15) kBq/m2– 90Sr and (55.0 ± 24.0) Bq/m2– 239+240Pu. The isotopic ratios137Cs/90Sr and 137Cs/239+240Pu for the territory of CIS and Eastern Europe are at the level (2.0 ± 0.71) and (25 ± 15), respectively.

Examination of a Method for Rapid Determination of Strontium-90 in Agricultural and Livestock Products, Indicator Plants Using Solid-phase Extraction with DGA Resin

Examination of a Method for Rapid Determination of Strontium-90 in Agricultural and Livestock Products, Indicator Plants Using Solid-phase Extraction with DGA Resin

ЗАСТОСУВАННЯ МЕТОДІВ СТАНДАРТИЗАЦІЇ СПЕКТРІВ БЕТА-ВИПРОМІНЮВАНЬ В РІДИННО-СЦИНТИЛЯЦІЙНОМУ ЛІЧЕННІ

The features of beta spectra standardization for modern liquid scintillation counting (LSC) us-ing Quantulus 1220TM alpha beta spectrometer are considered. The range of tasks is tritium meas-urement, beta-spectrometric determination of strontium-90, determination of strontium-90 by Che-renkov counting, determination of lead-210 in aerosol filters, radiocarbon studies. The purpose of the study was to summarize and analyze the peculiarities of the application of the methods of spectra standardization of beta-emitters in the study of radioactivity of environmental objects based on liquid scintillation counting. Materials and methods: liquid scintillation counting, LSC, Cherenkov counting, radiochemi-cal preparation of samples, spectra decomposition of beta-emitters. Results: Methods for spectra standardization of beta-emitters samples were analyzed in the study of 3H, 14C, 90Sr, 210Pb in environmental objects using a modern Quantulus 1220TM liquid scintil-lation spectrometer. The acceptability, effectiveness and scope of application of the methods of stand-ardization and spectra decomposition for beta-emitters for liquid scintillation counting and Cerenkov counting are grounded.

Evaluation of a sampling system coupled to liquid cathode glow discharge for the determination of rubidium, cesium and strontium in water samples

A simple sample introduction system has been successfully developed, and then integrated with liquid cathode glow discharge (LCGD) to form atomic emission spectrometry (AES) for the detection of rubidium (Rb), cesium (Cs) and strontium (Sr) in water samples by using a fiber-optic spectrometer, in which a buffer bottle was employed to improve the stability of microplasma, and a six-port valve equipped with sample loop was used to reduce the sample consumption and enhance the analytical precision and speed. The effects of flow rate, discharge voltage, supporting electrolyte and solution pH on signal intensity were examined systemically. The matrix interferences of major cations and anions in aqueous solution were also evaluated. The results indicated that the optimal operating conditions are 2.4 mL min−1 flow rate, 660 V discharge voltage and pH = 1.0 HNO3 as supporting electrolyte. Only Al3+ ions interfere with the determination of Rb, Cs and Sr. The limits of detection (LODs) of Rb, Cs and Sr are 0.18, 0.17 and 0.21 mg L−1, respectively, which are basically inferior to those of the closed-type electrolyte cathode atmospheric discharge (ELCAD). The relative standard deviation (RSD) is 2.7% for Rb, 2.0% for Cs and 2.5% for Sr, the correlationcoefficients (R2) of Rb, Cs and Sr are over 0.999, and the power is below 50 W. The measuredresults of Rb, Cs and Sr are in agreement well with the spiked values, and the satisfactory recoveries of standard addition are obtained between 97 and 111%. The advantages of small size, low sample and power consumption and high stability suggested that the LCGD-AES isa promising technique for the detection of Rb, Cs and Sr in water samples.

Determination of 90Sr activity concentration in black tea powder used as proficiency test sample by the modified liquid scintillation counting method

Environmental monitoring is very important in nuclear facilities and its surroundings during the construction and operation. It requires many and different radioactivity measurements in order to radiation protection, radioactive waste management and environmental protection. An accurate and reliable determination of Strontium-90 in various environment matrices has been studied with many techniques such as co-precipitation, ion exchange, solvent extraction and extraction chromatography for environmental contamination monitoring purposes. In this study, the method used for dissolution and radiochemical separation to determine strontium-90 activity concentration in tea matrix used as proficiency test sample with liquid scintillation counter was investigated. As a result of these studies, the average mean activity concentration of strontium-90 in proficiency test material was determined as 155 ± 16 Bq kg−1 dry matter (k = 2) by liquid scintillation efficiency tracing (CIEMAT/NIST) method for seven selected samples. This value was also confirmed by Joint Research Center-Geel with the CIEMAT/NIST method. The proficiency test results for consistency were checked by Dioxon's Q-test. Uncertainties arising from counting statistics, background, weighing, half-life, chemical recovery, efficiency and homogeneity were calculated.

Partial least squares modelization of energy dispersive X-ray fluorescence

As a proof of concept, a green methodology has been developed for the energy dispersive X-ray fluorescence (ED-XRF) determination of calcium, potassium, iron, magnesium, aluminum, chromium, strontium, phosphorus and nickel in the peel of untreated kaki fruit (Diospyros kaki. L) samples. ED-XRF spectra of fifty-six kakis purchased in the local area of LLombay (Valencia) were obtained directly from samples without any previous treatment and without sample damage just after cleaning the fruit with distilled water. Inductively Couple Plasma Optical Emission Spectrometry (ICP-OES) was used as a reference method to determine the mineral elements after microwave assisted acid digestion. XRF spectra and concentration values obtained by ICP-OES were processed using partial least squares (PLS) data treatment to build the corresponding chemometric models for prediction of mineral profile of samples. PLS-ED-XRF permits a direct and accurate determination of Ca and K in kaki peel. For Al, Fe, Mg, Ni and Sr screening semiquantitative results were obtained. Concentrations obtained directly by the internal calibration of instrument, using GeoChem Trace model, were also compared with data predicted by chemometric models being found that PLS models must replace the calibration of the instrument for thus kind of analysis.

Potential use of surface-assisted LIBS for determination of strontium in wines.

Laser-induced breakdown spectroscopy (LIBS) is a well-established technique for elemental analysis and has been widely used for qualitative and quantitative analysis of different solid samples. LIBS is also well-known for not requiring sample preparation, but the analysis of liquids is actually a great challenge. In the present work, a novel approach of elemental analysis of liquids with an organic matrix has been performed, to the best of our knowledge, making a liquid-to-solid matrix conversion by drying wine samples on aluminum and silicon wafers, which have demonstrated an increase in the analytical performance of LIBS. A red wine from Slovakia (not blended with any other variety or wine from other regions or adulterants) was prepared according to the procedure consisting of drying 2 ml of wine dropped on a solid wafer having a flat surface area of about 25 cm2. Surface-assisted LIBS in combination with the conversion of liquid into solid avoids the difficulties and limitations of working with liquid samples by LIBS, improving the limit of detection (LOD), repeatability, and sensitivity. The quantification of strontium (Sr) has been realized by addition of the known concentration of SrCl2·6H2O in wine before the drying process. Sr is an important element among those usually used as markers for identification of the soils on which the vines grow. Two ionic (407.771 nm and 421.552 nm) and two neutral (460.733 nm and 481.188 nm) Sr lines were used to plot the calibration curves in order to study the LODs and the matrix effects for the analysis of Sr in the tested wines and for different wafer materials. This direct surface-assisted LIBS measuring method has been successfully applied for the determination of Sr in a red wine sample from Slovakia, and the obtained results with two kinds of substrates (Al and Si) were compared. Finally, a validation sample has been employed to test the accuracy of the established calibration curves.

Simple Radiometric Determination of Strontium-90 in Seawater Using Measurement of Yttrium-90 Decay Time Following Iron-Barium Co-precipitation.

A radiometric quantitative methodology of 90Sr in seawater was developed using a measurement of the 90Y decay time following iron-barium co-precipitation. With calculations of its decay time, the radioactivity of 90Sr can be indirectly determined under conditional environmental samples. In addition, to avoid the interference of other radionuclide, the prepared samples were measured using a germanium semi-conductivity detector; then, the deposited radioactivity was subtracted from the actual measurement values of beta-ray counting. In this paper, the seawater samples were collected within 2 km around Fukushima Daiichi Nuclear Power Plants during the term from October 2011 to March 2012. This method showed good linearity between the 90Sr concentration and the total beta counting following the proposed method, with a correlation coefficient of 0.99 in seawater sample analysis. No interference that was caused by other radionuclides, such as radioactive cesium, was not observed in the quantification of 90Sr. The whole process requires 12 h to quantify 90Sr; this time is 1/40 shorter than traditional milking-low background gas-flow counting method. The lower limit of detection (average value n = 60) of the 90Sr radioactivity was shown to be 0.03 Bq/L (uncertainty 4.2%).

Simple ICP-OES based method for determination of selected elements in brewed ground and soluble coffees prior to evaluation of their intake and chemical fractionation

A simple method of simultaneous determination of aluminum (Al), barium (Ba), calcium (Ca), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), nickel (Ni), strontium (Sr) and zinc (Zn) in brews of ground and soluble coffees was proposed. It relied on acidification of brews with HNO3 to 1.3 mol L−1 and their analysis by inductively coupled plasma optical emission spectrometry. Precision of 0.1–9% and detection limits from 0.07 ng mL−1 (Sr) to 3 ng mL−1 (Ni) were achieved. Trueness of the method was verified by comparison of results with those achieved with wet digestion and by the recovery study, and was better than 5%. Additionally, chemical fractionation by tandem solid phase extraction with reverse-phase and strong cation-exchange extraction tubes was carried out. Differences in chemical fractionation patterns, particularly the residual fraction, was useful for differentiation of ground and soluble coffees by analysis of variance, principle component analysis and hierarchical clustering analysis.

Sequential Injection Analysis System Exploiting On-line Solid-phase Extraction for the Determination of Strontium and Nickel by Microwave Plasma Atomic Emission Spectrometry.

A sequential flow-based analysis system with on-line solid-phase extraction (SPE) columns coupled to microwave plasma atomic emission spectrometry (MP-AES) was developed for strontium and nickel determination. Crown ether chromatographic resin and dimethylglyoxime polymethacrylate resin were used for strontium and nickel retention under acidic and basic conditions, respectively; eluted with a nitric acid solution in both cases followed by MP-AES detection. The calculated detection limits were 0.25 μg L-1 for strontium and 3.56 μg L-1 for nickel.

On-line pseudo-stationary magnetic solid-phase extraction using magnetic cation exchange microparticles and its application to the determination of strontium

An on-line magnetic solid-phase extraction system was developed for Sr determination.

Determination of strontium 90 in environmental samples by triple quadrupole ICP-MS and its application to Fukushima soil samples

The determination of 90Sr by triple quadrupole ICP-MS is capable of providing a high sample throughput compared with radiometric analytical methods.

Vortex-assisted liquid-liquid microextraction of strontium from water samples using 4',4″(5″)-di-(tert-butylcyclohexano)-18-crown-6 and tetraphenylborate.

A vortex-assisted liquid-liquid microextraction method was developed for the chromatographic determination of strontium in aqueous samples. In the method, strontium was complexed with 4',4″(5″)-di-(tert-butylcyclohexano)-18-crown-6 in the presence of tetraphenylborate as the counter anion, which increased the hydrophobicity of the ion-association complex, resulting in its improved extraction into 1-octanol. Strontium from the organic phase was stripped with nitric acid back to aqueous solution and determined by ion chromatography. The optimum microextraction conditions were as follows: 2.0mL aqueous samples with 3mM tetraphenylborate; 150μL of 1-octanol as the extractant phase with 10mM DtBuCH18C6; vortex extraction time for 10s; centrifugation at 6000rpm for 4min; stripping by 0.1M nitric acid. Under the optimum conditions, the detection limit for strontium was 0.005mg/L. The calibration curves showed good linearity over the range between 0.01 and 2.5mg/L. Intra- and interday precisions of the present method were satisfactory with relative standard deviations of 1.7 and 2.1%, respectively.

Determination of stable cesium and strontium in rice samples by inductively coupled plasma mass spectrometry

For long-term radiation dose assessment models, food ingestion is one of the major exposure pathways to human. In general, the stable isotopes can serve as analogues of radioisotopes. In this study, rice samples were collected from 30 paddy fields in Si Sa Ket, Yasothon and Roi Et in the northeast of Thailand in November 2014. The concentrations of stable cesium (Cs-133) and strontium (Sr-88) in polished rice were determined by inductively coupled plasma mass spectrometry (ICP-MS). The standard reference material of rice flour (NIST 1568a) with spiked Cs and Sr was used to validate the analytical method. The concentration of Cs in polished rice from Si Sa Ket, Yasothon and Roi Et was 0.158 ± 0.167 mg kg-1, 0.090 ± 0.117 mg kg-1 and 0.054 ± 0.031 mg kg-1, respectively. The concentration of Sr in polished rice from Si Sa Ket, Yasothon and Roi Et was 0.351 ± 0.108 mg kg-1, 0.364 ± 0.215 mg kg-1 and 0.287 ± 0.102 mg kg-1, respectively. Comparison of the results with Japanese data before the Fukushima Di-ichi nuclear power plant accident showed that the concentrations of both Cs and Sr for Thai rice were higher than those for Japanese rice.

Calibration of the 125I-induced x-ray fluorescence spectrometry-based system of in vivo bone strontium determinations using hydroxyapatite as a phantom material: a simulation study

Objective. The calibration of in vivo x-ray fluorescence systems of bone strontium quantification, based on 125I excitation, is dependent on a coherent normalization procedure. Application of this procedure with the use of plaster of Paris (poP) as a phantom material requires the application of a coherent conversion factor (CCF) to make the calibration functions transferable between the phantom material and human bone. In this work we evaluate, with the use of Monte Carlo simulation, the potential benefit of employing a newly developed hydroxyapatite phantom material into the calibration protocol. Approach. Simulations being performed on bare bone phantoms, as the emission spectrum in this case is equivalent to an emission spectrum of an adequately corrected measurement for soft tissue attenuation of emitted strontium signal. We report that the application of hydroxyapatite phantoms does in fact remove the need for a coherent correction factor (CCF). Main results. The newly developed phantoms can thus be used for the calibration of in vivo bone strontium systems removing one step of the calibration protocol. Calibration is, however, limited to cases in which the concentration is relative to the amount of calcium in the specimen, which is, the most useful quantity in a clinical sense. Determining concentrations on a per-mass-of-material basis, that is, a concentration not normalized to the calcium content of the phantom/bone, results in large biases in estimated bone strontium content. Significance. The use of an HAp phantom material was found to remove the need for a CCF. It was also found that in the case of an incomplete conversion ratio when preparing the phantom material that there would be little effect on the differential coherent cross-section and thereby the coherent normalization-based calibration protocol.

A Rapid Extraction Procedure for the Determination of Strontium-90 in Water Samples

A Rapid Extraction Procedure for the Determination of Strontium-90 in Water Samples