用无机离子交换剂制备90Sr-90Y发生器的研究

研究了无机离子交换剂硅酸锑(SS)、焦磷钨酸锡(SWPP)等的制备以及它们对锶、钇的选择性;研究了硅酸锑(SS)的热稳定性和辐照稳定性.结果表明不同的无机离子交换剂对锶、钇的选择性差别很大,硅酸锑(SS)制备工艺简单,对锶有较强的选择性且介质酸度对其选择性影响较大,具有良好的热稳定性和辐照稳定性.在柱式操作中,对锶和钇的分离系数最大可达5.5 ×104.     

Urine strontium-90 (Sr-90) manual and automated pre-analytical separation followed by liquid scintillation counting

Journal of Radioanalytical and Nuclear Chemistry - Responding to a radiological or nuclear incident may require assessing tens to hundreds of thousands of people for possible radionuclide...     

A Simple and Rapid Method for the Preparation of 87Y/87mSr Generator

A simple and efficient process for the preparation of ⁸⁷Y/^87mSr generator with adsorption chromatography on -Fe₂O₃ was developed. A 0.25 g pallet of natural SrCl₂ was employed as a solid target which was irradiated at INER TR30/15 cyclotron. After irradiation the target was dissolved into a saline solution and adjusted with HCl/NaOH to a pH of 6.3. This solution was then passed directly through the column (1 cm×4 cm), loaded with appropriate amounts of -Fe₂O₃, at a flowrate of 1.0 ml/min for adsorption of ⁸⁷Y. Nonradioactive Sr was unadsorbed and washed out from the column. Above 90% of the available ^87mSr with a ⁸⁷Y breakthrough less than 10^–3% could be obtained with 10 ml of 0.9% saline solution per elution from the generator system. The chemical contaminants of Fe and Sr in the eluates were found below 0.04 and 0.1 ppm, respectively.     

Extraction chromatographic separation of carrier-free90Y from90Sr/90Y generator by crown ether coated silica gels

A remarkable extraction chromatographic method for the preparation of⁹⁰Y of high radiochemical purity has been developed. The generator consists of silica gel coated crown ether. It functions as a strong adsorber for⁹⁰Sr and in the meantime high purity of⁹⁰Y is eluted with a dilute solution of picric acid after a suitable period. The experiments indicated that DC18C6 coated silica gel is better than that of DB18C6 coated. The extraction capacity of strontium on 3.8% DC18C6 coated silica gel is 5.6 mg Sr/g silica gel. Yttrium is obtained with more than 95% milking yield with radionuclide purity greater than 99.9%. The extraction chromatographic generator does not change its characteristics even after 5 elutions.     

The use of liquid scintillation spectrometry for the determination of radionuclidic purity of 90Y from a radiochemical 90Y/90Srgenerator

Summary An extraction technique for the separation of ⁹⁰Sr from a high excess of⁹⁰Y has been developed. This procedure can be used for the determination of trace amounts of⁹⁰Sr in⁹⁰Y prepared by a radiochemical⁹⁰Y/⁹⁰Sr generator by liquid scintillation.     

Characterization and calibration of a large area beta scintillation detector for determination of Sr-90

A large area beta scintillation detector has been developed which is currently capable of determining Sr-90/Y-90 contamination in surficial soils. The detector system employs scintillating fiber optic arrays, with active dimensions approximately 15 cm wide by 100 cm long, both ends of which are coupled to multiple photomultiplier tubes (PMTs). Electronic processing includes coincidence requirements to optimize sensitivity and selectivity for the 2.28 MeV (maximum) beta particle from Y-90. Low energy beta particles and gamma rays are discriminated against using double ended and multi-layer coincidence requirements. The detector system is personal-computer-software controlled and data restored in a format compatible with standard database software for ease of final data reduction. Experimental calibration studies have shown a linear response for Sr-90/Y-90 soil concentrations from 12 to over 500 pCi/g and a discrimination factor of 50 to 1 versus Cs-137.Pacific Northwest Laboratory is operated for the U.S. Department of Energy by Battelle Memorial Institute under Contract DE-AC06-76RLO 1830.     

Preparation and quality control and biodistribution studies of [90Y]-DOTA-cetuximab for radioimmunotherapy

Yttrium-90 is a useful radionuclide for radioimmunotherapy (RIT) and the anti-epidermal growth factor receptor (anti-EGFR) antibody cetuximab is clinicsally approved for the treatment of EGFR-expressing metastatic colorectal cancer and advanced head and neck cancer. Thus in this work radiolabeling of monoclonal anti-EGFR with ⁹⁰Y for radioimmunotherapy (RIT) is targetted. Cetuximab was successively labeled with [⁹⁰Y] chloride (74 MBq) 2 mCi after conjugation with macrocyclics bifunctional chelating agent, 1,4,7,10-tetraazacyclododecane-N,N′,N″,N″′-tetraacetic acid mono-(N-hydroxysuccinimidyl) ester (DOTA-NHS), purified and concentrated by centrifugation using an Amicon Ultra-15 filter (Millipore, MWCo, 30000). ⁹⁰Y chloride was obtained by ⁹⁰Sr/⁹⁰Y generator. Radiolabeling was completed in 2 h by the addition of DOTA-cetuximab conjugate at 42 °C. The stability of radiolabeled was studied in human serum. Biodistribution studies in normal rats were carried out to determine the radioimmunoconjugate distribution up to 96 h. Radiochemical purity of 92 % (using ITLC) was obtained for final radioimmunoconjugate (Specific activity = 0.55 GBq/mg). Stability of radiolabeled protein in presence of human serum was tested at 37 °C for up to 24 h. Biodistribution studies demonstrated the highest ID/g % in the blood (2.62 ± 0.005 at 24 h) and the liver (2.19 ± 0.001). This study demonstrated that ⁹⁰Y-DOTA-cetuximab is a potential compound for the treatment of EGFR-expressing cancers.     

Rapid determination of 90Sr in urine samples using AnaLig® Sr-01

This paper describes the use of IBC’s AnaLig^® Sr-01 molecular recognition technology product to effectively and selectively pre-concentrate, separate, and recover strontium from urine samples. This method uses two-stage columns separation consisting of two different commercial products Eichrom’s Pre-filter Material and AnaLig^® Sr-01 column from IBC Advanced Technologies. This method does not involve co-precipitation of strontium as phosphates and oxalates from urine samples. The new rapid method separates strontium-90 with high chemical recovery.     

90Sr/90Y determination in milk by Cherenkov radiation after microwave digestion

Journal of Radioanalytical and Nuclear Chemistry - A separation procedure was developed and implemented for the isolation of gold (Au) and platinum (Pt) radionuclides from deuteron irradiated Pt...     

Optimization of Sr-90 precipitation in nitric acid using design of experiments for radioactive waste characterization method

Journal of Radioanalytical and Nuclear Chemistry - 90Sr radiochemical method using nitric acid for Sr and Ca separation was optimized using design of experiments methodology. Nitric acid...     

Spatial modelling of Cs-137 and Sr-90 fallout after the Fukushima Nuclear Power Plant accident

Journal of Radioanalytical and Nuclear Chemistry - Determination of radionuclides transport characteristics is among the most significant research topics, which require extensive multidisciplinary...     

Evaluation of interferences on measurements of 90Sr/90Y by TDCR Cherenkov counting technique

A study to evaluate conditions affecting the determination of ⁹⁰Sr/⁹⁰Y activities in liquid samples by the triple-to-double coincidence ratio (TDCR) Cherenkov counting technique was conducted. The Cherenkov radiation produced by the ⁹⁰Y beta decay was determined using a commercially available Hidex 300 SL liquid scintillation counter. The interferences of sample geometry, including sample counting vial type and volume composition, and sample colour on the TDCR were investigated. The effects of potentially interfering beta and mixed beta–gamma emitters on the TDCR Cherenkov counting of ⁹⁰Sr/⁹⁰Y activities were also examined. The TDCR values were used to quantify counting efficiencies of ⁹⁰Y under different experimental conditions. The results demonstrated that the Cherenkov counting efficiency of ⁹⁰Y is independent of sample volume and counting vial size. The effect of colour quenching was examined using yellow and brown food-grade dyes. The TDCR correction for colour quenching was found to be effective. An evaluation of counting efficiency of different beta-emitting radionuclides demonstrated that strong gamma emissions can contribute to the Cherenkov counting efficiency. Overall, measured radioactivity values deviated from reference values by ≤7.5 %, which is acceptable for screening applications in emergency situations.     

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.     

Validation of an extraction paper chromatography (EPC) technique for estimation of trace levels of 90Sr in 90Y solutions obtained from 90Sr/90Y generator systems

While the extraction paper chromatography (EPC) technique constitutes a novel paradigm for the determination of few Becquerels of ⁹⁰Sr in MBq quantities of ⁹⁰Y obtained from ⁹⁰Sr/⁹⁰Y generator, validation of the technique is essential to ensure its usefulness as a real time analytical tool. With a view to explore the relevance and applicability of EPC technique as a real time quality control (QC) technique for the routine estimation of ⁹⁰Sr content in generator produced ⁹⁰Y, a systematic validation study was carried out diligently not only to establish its worthiness but also to broaden its horizon. The ability of the EPC technique to separate trace amounts of Sr²⁺ in the presence of large amounts of Y³⁺ was verified. The specificity of the technique for Y³⁺ was demonstrated with ⁹⁰Y obtained by neutron irradiation. The method was validated under real experimental conditions and compared with a QC method described in US Pharmacopeia for detection of ⁹⁰Sr levels in ⁹⁰Y radiopharmaceuticals.     

A rapid method for analysis of non-equilibrated 90Sr/90Y in infant formula

Journal of Radioanalytical and Nuclear Chemistry - A rapid analytical method for quantifying 90Sr in infant formula prior to secular equilibrium is presented. The approach is dependent on the use...     

A prototype of an extrapolation chamber for beta radiation beams of 90Sr+90Y

Extrapolation chamber is the only primary standard dosimeter for beta radiation. With the aim to test new configurations and materials using easily-available and low-cost materials and fulfill the need of a chamber for scientific metrological purposes, in this paper the prototype of an extrapolation chamber has been built and its performance has been investigated in the beta radiation field of ⁹⁰Sr+⁹⁰Y. The main differences between the chamber and commercially available chambers are the geometry, constituent material and configuration. The obtained results were compared with those of the calibration certificate of the source and an agreement within 4 % was verified. The depth-dose curve was also obtained and compared with the curve published in ISO 6980, showing a good agreement. Moreover, Monte Carlo simulation was undertaken using MCNP4C code and the relative difference of 0.3 % was observed compared to the experiment. All of the results proved the suitability of the chamber in the beta radiation field of ⁹⁰Sr+⁹⁰Y.     

Rapid determination of 90Sr/90Y in water samples by liquid scintillation and Cherenkov counting

Strontium-90 (⁹⁰Sr) is a ubiquitous contaminant at nuclear facilities, found at high concentrations in spent nuclear fuel and radioactive waste. Due to its long half-life and ability to be transported in groundwater, an accurate method for measuring ⁹⁰Sr in water samples is critical to the monitoring program of any nuclear facility. To address this need, a rapid procedure for sequential separation of Sr/Y was developed and tested in groundwater samples collected from an area of riverbed affected by a ⁹⁰Sr groundwater plume. Sixteen samples, plus spike and water blanks, were analyzed. Five different measurements were performed to determine the ⁹⁰Sr and yttrium-90 (⁹⁰Y) activities in the samples: direct triple-to-double-coincidence ratio (TDCR) Cherenkov counting of ⁹⁰Y, liquid scintillation (LS) counting for ⁹⁰Sr following radiochemical separation, LS counting for ⁹⁰Y following radiochemical separation, Cherenkov counting for ⁹⁰Y following radiochemical separation and LS counting of the Sr samples for ⁹⁰Y in-growth. The counting was done using a low-level Hidex 300SL TDCR counter. Each measurement method was compared for accuracy, sensitivity and efficiency. The results following Cherenkov counting and radiochemical separation were in very good agreement with one another.