The methodology for the rapid determination of 89,90Sr in wide range of activity concentration is given. Methodology is based on simultaneous separation of strontium and yttrium from samples by mixed solvent anion exchange chromatography, mutual separation of 89,90Sr from 90Y by hydroxide precipitation and quantitative 89,90Sr determination by Cherenkov counting within 3 days. It is shown that Y and Sr can be efficiently separated from alkaline, alkaline earth and transition elements as well as from lanthanides and actinides on the column filed by strong base anion exchanger in nitrate form and 0.25 M HNO3 in mixture of ethanol and methanol as eluent. Decontamination factor for Ba, La and other examined elements except calcium is low and can not affect quantitative determination in predictable circumstances. Methodology for quantitative determination by Cherenkov counting based on following the changes of sample activity over time is described and discussed. It has been shown that 89,90Sr can be determined with acceptable accuracy when 89Sr/90Sr ratio is over 10:1 and that separation of Y enables reliable determination of 89Sr and 90Sr in wide range of 89Sr/90Sr ratios (60:1) and in some cases in presence of other yttrium and strontium isotopes. The methodology was tested by determination of 89,90Sr in Analytics crosscheck samples (nuclear waste sample) and ERA proficiency testing samples (low level activity samples). Obtained results shows that by using of low level liquid scintillation counter it can be possible to determine 89Sr and 90Sr in wide range of concentration activity (1–1,000 Bq/L/kg) with uncertainty below 10% within 2–3 days. Results also show that accuracy of determination of 89Sr (and 90Sr) strongly depends on the determination of difference between separation and counting time when activity ratio of 89Sr/90Sr is high. Examination the influence of media and vial type on background radiation and counting efficiency has shown that lowest limit of determination can be obtained by using of HNO3 in plastic vials as counting media, because in this combination figure of merit is maximized. For the recovery of 50% and 100 min of counting time estimated MDA is 55 Bq and 90 Bq for 90Sr and 89Sr, respectively. Analysis of combined uncertainty shows that it mainly depends on uncertainty of efficiency and recovery determination, uncertainty of activities determination for both isotopes and level of background radiation.

Rapid determination of 89,90Sr in wide range of activity concentration by combination of yttrium, strontium separation and Cherenkov counting

Selective removal of Sr(II) from saliferous radioactive wastewater by capacitive deionization.

The annual bibliographic review of GGR has a long tradition dating back to 1981, this being the thirty-second instalment to appear. The review contains references to articles from geochemical, geological, environmental and chemical journals in which data of reference materials (RMs) and certified RMs (CRMs) were published. The current definitions for a RM and a CRM are published in the ISO Guide 30 Amendment 1 (2008): A RM is a material, sufficiently homogeneous and stable with respect to one or more specified properties, which has been established to be fit for its intended use in a measurement process, and a CRM is a RM characterised by a metrologically valid procedure for one or more specified properties, accompanied by a certificate that provides the value of the specified property, its associated uncertainty, and a statement of metrological traceability. RMs and CRMs are necessary for quite different purposes, such as calibration, method validation, quality control and assurance, and to establish metrological traceability to measurements (Wiedenbeck et al. 2012).

Geostandards and Geoanalytical Research Bibliographic Review 2011

The radioactivity of 90Sr and 137Cs in environmental samples, bark and leaf, collected around the Fukushima Daiichi Nuclear Power Plant in May 2013 was determined with the aim of investigating the migration of both nuclides using their radioactivity ratio. The radioactivity of 90Sr was determined by using Cherenkov counting of 90Y after purification using Sr resin and that of 137Cs was determined by γ-spectrometry. Quench correction in Cherenkov counting was investigated by measurements of samples spiked with purified 90Y revealed that the radioactivity could be evaluated without quench correction. The radioactivity ratio of 90Sr to 137Cs in bark samples of 4.2 × 10−3 and 1.2 × 10−2 was compared with the results from soil samples collected in July 2011 to show that the migration of 90Sr was slower than 137Cs in bark and tree.

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Cherenkov counting of 90Sr and 90Y in bark and leaf samples collected around Fukushima Daiichi Nuclear Power Plant

According to a comprehensive environmental radioactivity survey in the South Caspian region, 137Cs distribution in water, sediment and soil were measured in the Anzali lagoon of the Caspian Sea, Ir...

137Cs distribution in the South Caspian region, transfer to biota and dose rate assessment

Determination of 90Sr in environmental solid samples is a challenging task because of the presence of so many other radionuclides in samples of interest. This problem was dealt with by radiochemical separation of strontium followed by yttrium separation and Cerenkov counting of the high-energy β-particle emissions of 90Y in order to quantitate 90Sr. In this work, an improved method is described for the determination of 90Sr in soil samples, through the separation of the daughter 90Y at equilibrium. The procedure is based on the HDEHP solvent extraction in combination with liquid scintillation spectrometry (LSS). A low background Quantulus has been optimized for low level counting of Cerenkov radiation emitted by the hard β-emitter 90Y. The analytical quality of the method has been checked by analyzing IAEA Soil-375 reference materials. The analytical method has also been successfully applied to the determination of 90Sr for moss-soil samples in inter-laboratory exercises through IAEA’s ALMERA network. The chemical recovery for 90Y extraction ranged from 80 to 85% and the counting efficiency was 73% in the window 25–400 keV.

Filiz Karacan

Papers

The simple radiochemical determination of 90Sr in environmental solid samples by solvent extraction