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1.
Abstract

Five diglycolamide-appended calix[4]arene (C4DGA) ligands, viz. C4DGA with no substituent (L-I), n-propyl (L-II), 3-pentyl (L-III), n-octyl (L-IV) and both side (L-V) substituents were evaluated for the separation of carrier free 90Y from a 90Y–90Sr mixture using the flat sheet supported liquid membrane technique. Based on the results of earlier batch studies, the transport properties of the C4DGA ligands towards Y(III) and Sr(II) were monitored at two different feed acidities. The transport rates were significantly lower for 6 M HNO3 as compared to 3 M HNO3 as the feed. After 6 h, the observed trend of Y(III) transport with the C4DGA ligands using a feed of 3 M HNO3 was: L-I ~ L-III > L-V > L-IV > L-II which changed to L-III > L-I > L-IV > L-V > L-II for 6 M HNO3 as the feed. With 3 M HNO3 as feed, >97% Y(III) transport was obtained with L-I and L-III in 6 h. Comparative Sr(II) transport was negligible resulting in high decontamination factors. In a one-step separation process, using L-I as the carrier ligand, pure 90Y was obtained as the respective complex with either EDTA or DOTA. The highlights of this liquid membrane-based separation method comprise: its easiness, one-step separation, low ligand inventory, relatively pure product and continuous method.  相似文献   

2.
Yttrium-90 is an important radionuclide known for its therapeutic application in nuclear medicine. Solvent extraction studies with N,N,N’,N’-tetra-octyldiglycolamide (TODGA) has shown that Y(III) is well extracted in 6 M HCl while at the same time, extraction of Sr(II) is very low leading to a separation factor (DY/DSr = 60,000). This property of TODGA can be exploited for the separation of Y from Sr. The aim of this present work is to produce carrier free 90Y by using Supported Liquid Membrane (SLM) based separation of Y and Sr with TODGA as the carrier. Solvent extraction studies with various diluents viz. 1-decanol, xylene, MIBK, chloroform etc. indicated that xylene and n-dodecane are most suitable as S.F. >50,000 are obtained. Based on the results, a SLM based separation scheme was developed using 0.1 M TODGA in xylene loaded on a microporous PTFE membrane as a polymeric support and 6 M HCl as feed and 0.01 M HCl as strip phase. The results appear promising for the development of SLM based Y-90 generator. The purity of the product was ascertained by the half life method.  相似文献   

3.
Solvent extraction and supported liquid membrane transport studies on Y(III) and Sr(II) were carried out using both nitric as well as hydrochloric acid feed conditions using N,N,N′,N′-tetra-octyldiglycolamide (TODGA) in several organic diluents. The solvent extraction studies indicated extremely large separation factor (SF) values with chloroform, carbon tetrachloride, 1-decanol and hexone when 6 M HNO3 was used as the feed. On the other hand, the SF values were 1–2 orders of magnitude lower when the nitric acid concentration was 3 M HNO3. Significantly large SF values were also obtained from 6 M HCl when xylene, carbon tetrachloride, n-dodecane and hexone were used as the diluent. Though mass transfer was not very promising in the supported liquid membrane studies with most of the diluent systems, quantitative Y(III) transport was observed with 0.1 M TODGA in xylene with negligible Sr(II) transport suggesting possibility of obtaining carrier free 90Y. The purity of the radiotracer was checked by half-life method.  相似文献   

4.
The distribution coefficient measurements on Y(III) and Sr(II) were performed using ditertiarybutyl dicyclohexano 18-crown-6 (Sr-selective resin) and N,N,N′,N′-tetraoctyldiglycolamide (Y-selective resin) in HNO3, HCl and HClO4 media. Separation factors (90Y/90Sr) based on distribution coefficient data suggested that perchloric acid is distinctly better medium as compared to nitric acid/hydrochloric acid. The mechanism of extraction changes with the nature and concentration of acid and is responsible for the high selectivity in perchloric acid medium. Sequential column studies were carried out on tracers (radioactive/stable) employing Sr-selective/Y-selective extraction chromatographic resins as stationary phases. The final elution of 90Y was done in 0.01 M EDTA at pH 4.0 which can be used for clinical applications after radiochemical processing.  相似文献   

5.
To partition Sr(II) from highly active liquid waste (HLW), a macroporous silica-based 4,4',(5')-di(t-butylcyclohexano)-18-crown-6 (DtBuCH18C6)-tri-n-butyl phosphate (TBP) polymeric composite, (DtBuCH18C6+TBP)/SiO(2)-P, was synthesized. It was done by impregnation and immobilization of DtBuCH18C6 and TBP into the pores of the SiO(2)-P particles, where DtBuCH18C6 was modified with TBP. The sorption of Sr(II) and some co-existent elements contained in a simulated HLW onto (DtBuCH18C6+TBP)/SiO(2)-P was investigated at 323 K. It was found that in 2.0 M HNO(3), Sr(II) exhibited strong sorption ability and high selectivity over all the tested metals except Ba(II). Chromatographic partitioning of Sr(II) from 2.0 M HNO(3) containing 5 mM of the tested elements was performed by (DtBuCH18C6+TBP)/SiO(2)-P packed column. La(III), Y(III), Na(I), K(I), Cs(I), Ru(III), Mo(VI), and Pd(II) had almost no sorption and flowed into effluent along with 2.0 M HNO(3). Sr(II) adsorbed strongly by (DtBuCH18C6+TBP)/SiO(2)-P was then eluted effectively by water, while Ba(II) flowed into effluent along with Sr(II) due to the similar chemical properties. In addition, the bleeding of total organic carbon in aqueous phase was evaluated. The results demonstrated that in 2.0 M HNO(3), application of the macroporous silica-based DtBuCH18C6 polymeric composite in chromatographic partitioning of Sr(II) from the simulated HLW is feasible.  相似文献   

6.
To partition effectively Cs(I) and Sr(II), two harmful heat emitting nuclides, from a highly active liquid waste by extraction chromatography, two kinds of macroporous silica-based polymeric materials, Calix[4]arene-R14/SiO(2)-P and TODGA/SiO(2)-P, were synthesized. Two chelating agents, 1,3-[(2,4-diethyl-heptylethoxy)oxy]-2,4-crown-6-calix[4]arene (Calix[4]arene-R14), an excellent supramolecular compound having molecular recognition ability for Cs(I), and N,N,N',N'-tetraoctyl-3-oxapentane-1,5-diamide (TODGA) were impregnated and immobilized into the pores of SiO(2)-P particles support by a vacuum sucking technique. The loading and elution of 11 typical simulated fission and non-fission products from 4.0M or 2.0M HNO(3) were performed at 298K. It was found that in the first column packed with the Calix[4]arene-R14/SiO(2)-P, all of the simulated elements were separated effectively into two groups: (1) Na(I), K(I), Sr(II), Fe(III), Ba(II), Ru(III), Pd(II), Zr(IV), and Mo(VI) (noted as Sr-group); (2) Cs(I)-Rb(I) (Cs-group) by eluting with 4.0M HNO(3) and distilled water, respectively. The harmful element Cs(I) flowed into the second group along with Rb(I) because of their close sorption and elution properties towards Calix[4]arene-R14/SiO(2)-P, while Sr(II) showed no sorption and flowed into Sr-containing group. In the second column packed with TODGA/SiO(2)-P, the Sr-group was separated into (1) Ba(II), Ru(III), Na(I), K(I), Fe(III), and Mo(VI) (non-sorption group); (2) Sr(II); (3) Pd(II); and (4) Zr(IV) by eluting with 2.0M HNO(3), 0.01M HNO(3), 0.05M DTPA-pH 2.5, and 0.5M H(2)C(2)O(4), respectively. Sr(II) adsorbed towards TODGA/SiO(2)-P flowed into the second group and showed the excellent separation efficiency from others. Based on the elution behavior of the tested elements, an advanced PREC (Partitioning and Recovery of two heat generators from an acidic HLW (high activity liquid waste) by Extraction Chromatography) process was proposed.  相似文献   

7.
Separations of tracer cations in parent daughter systems such as carrier-free210Bi from210Pb,90Y from90Sr and UX1 from U have been carried out in a column of ceric phosphate as ion exchanger. The exchanger has been prepared by mixing ceric sulfate in hot 10M orthophosphoric acid at 80°C and keeping for overnight. A pale yellow coloured precipitate was formed which was washed, dried at 70°C for 48 hours when a hard, granular variety suitable for column use, with a cerium to phosphate ratio of 1∶2 was obtained. 0.1M H3PO4 was used as medium in each of the systems studied. The β-decay curves of the separated210Bi and90Y and the γ-spectrum of UX1 show that all these activities are radiochemically pure. The separation procedures adopted in each case were very clean and simple, gave quantitative yields and took less than half an hour.  相似文献   

8.
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.  相似文献   

9.
Two kinds of novel macroporous silica-based chelating polymeric adsorption materials, TODGA/SiO2-P and CMPO/SiO2-P, were synthesized by impregnating and immobilizing two chelating agents, N,N,N',N'-tetraoctyl-3-oxapentane-1,5-diamide (TODGA) and octyl(phenyl)-N,N-diisobutylcarbamoylmethylphoshine oxide (CMPO), into the pores of SiO2-P particles. To separate minor actinides (MA(III)) such as Am(III) and Cm(III), the adsorption and elution of 13 typically simulated fission products from a 3 M HNO3 were performed. It was found that in the first column packed with TODGA/SiO2-P, all of the simulated elements were separated effectively into four groups: (1) Cs(I), Mo(VI), and the most portion of Ru(III) (non-adsorption group), (2) Sr(II), small portion of Gd(III) and all of light REs(III) (MA-lRE-Sr group), (3) most of Gd(III) and all heavy RE(III) (hRE group), and (4) Zr(IV), Pd(II), and a little of Ru(III) (Zr-Pd group) by eluting with 3.0 M HNO3, 1.0M HNO3, distilled water, and 0.5 M H2C2O4, respectively, at 298 K. MA(III) was predicted to flow into the second group along with Nd(III) because of their close adsorption-elution onto TODGA/SiO2-P. In the second column packed with CMPO/SiO2-P, MA-lRE-Sr group was separated into (1) Sr(II), (2) middle RE(III) such as Gd(III), Eu(III), Sm(III), and quite small portion of Nd(III) (MA-mRE), and (3) light RE(III) such as La(III), Ce(III), and most of Nd(III) by eluting with 3.0 M HNO3 and 0.05 M DTPA-pH 2.0, respectively, at 323 K. MA(III) was believed to flow into MA-mRE group along with Gd(III) due to their similar adsorption properties towards CMPO/SiO2-P. Based on positions of MA(III) appeared in light and heavy RE(III), an improved MAREC process for MA(III) partitioning from HLW was proposed.  相似文献   

10.
The production of 90Y by 90Sr-90Y generator was studied. 90Sr was adsorbed on a column with Aminex A-5 resin. The daughter radionuclide 90Y was eluted with 0.7M -hydroxyisobutyrate (-HIB, pH 5.4). Radionuclidic, radiochemical and chemical purities were >98% and yield >85%. After converting into chloride form 90YCl3-solution (pH:1) was used for preparing injectable yttrium citrate and labeling some other radiopharmaceuticals. Furthermore, a fast ITLC-method for the determination of 90Sr in 90Y-eluate was developed.  相似文献   

11.
A generator system has been developed for the preparation of carrier-free 90Y from 90Sr present in the high level waste (HLW) of the Purex process by employing a supported liquid membrane (SLM) using 2-ethylhexyl-2-ethylhexyl phosphonic acid (KSM-17 equivalent to PC 88A) supported on a polytetrafluoro ethylene (PTFE) membrane. When uranium depleted Purex HLW at appropriate acidity is passed sequentially through octyl (phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) sorbed on chromosorb-102 (abbreviated as CAC) and Zeolite AR1 (synthetic mordenite) columns, all the trivalent, tetravalent and hexavalent metal ions and monovalent 137Cs ions are sorbed. After adjusting to pH 2 with NaOH the resulting effluent is used as feed in a single stage membrane cell partitioned with a PTFE membrane impregnated with KSM-17 and having a feed and receiver compartment with 5.0 ml capacity each. The receiver compartment was filled with a 0.5M HNO3 or 0.5M HCl stripping solution. 90Y alone is preferentially transported across the membrane leaving behind all the impurities viz. 90Sr, 125Sb, 106Ru, 106Rh, etc. in the feed compartment. This technique can yield 90Y in mCi levels in a pure and carrier-free form for medical applications. The feed can be reused repeatedly after allowing for 90Y buildup.  相似文献   

12.
The extraction of strontium(II) and yttrium(III) ions from aqueous solutions at various pH values into methyl isobutyl ketone containing I-phenyl-3-methyl-4-caprylpyrazolone-5 is described. Quantitative extraction of Sr and Y at pH 8.6–10 and pH 2.8–5.4 respectively is utilized for the carrier-free production of 90Y from 90Sr–90Y mixtures and 89Sr from neutron-irradiated yttrium oxide. A clean separation of these elements from each other and more than 95% calculated activities were recovered  相似文献   

13.
A new zirconium vanadate (Zr–V) ion-exchanger was synthesized and characterized for fast and selective separation procedure of 90Y from 89Sr. The method was based on 90Y(III) sorption from aqueous HCl solution containing 89Sr(II) onto Zr–V gel exchanger. The kinetics of Y(III) sorption from HCl solution by Zr–V exchanger was subjected to Weber–Morris, Lagergren, Bhattacharya and Venkobachar, and Bt models. Initially, the uptake of Y(III) onto the exchanger was fast followed by kinetically first-order sorption with an overall rate constant, K Lager = (3.55 ± 0.03) × 10?4 min?1. Film and intraparticle transport are the two steps that might influence Y(III) sorption. The negative values of ΔG of 90Y retention dictate that, the process is a spontaneous. The negative values of ΔH and ΔS reflect the exothermic nature of 90Y(IIsorption and the random uptake of 90Y(III) onto Zr–V sorbent. Zr–V exchanger offers unique advantages of 90Y(III) retention over conventional solid sorbents in rapid and effective separation of traces of 90Y(III) from Sr. The exchanger was successfully packed in column for an effective separation of 90Y.  相似文献   

14.
No-carrier-added 90Y was separated from 90Sr via colloid formation of 90Y in basic media. The mixture was passed through glass wool or membrane filter. The filtrate contained 90Sr, while 90Y was retained on glass wool/membrane filter. Yttrium-90 was extracted with 0.1 M HCl. Contamination of 90Sr was <0.0001%. More than 98% labeling yield of 90Y-EDTMP was confirmed by paper chromatography.  相似文献   

15.
Special attention has been given to the separation and recovery of VII-group elements, Tc and Re, in relation to the partitioning of high-level liquid waste (HLLW) generated from the nuclear fuel reprocessing process. In this study, a tertiary amine (tri-n-octylamine, TOA), which is effective for the extraction of oxoanions, was encapsulated in Ca and H-types of alginate xerogel polymers (CaALG, HALG). The uptake behaviors of TcO4-and ReO4 (substitute of Tc) in the presence of HNO3 were examined by batch method using TOA-xerogel microcapsules (TOA-CaALG, TOA-HALG). The uptake of TcO4- in the presence of 0.1 M HNO3 was readily attained within 5 h, and a relatively large uptake(%) above 90% was obtained. The uptake(%) of Re(VII) for TOA-CaALG in the presence of 0.01∼0.1 M HNO3 was estimated to be about 90%, while gradually decreasing with HNO3 concentration, indicating that the extraction of HNO3 with TOA became dominant in this process: R3NH+NO3 (o) + ReO4 (aq) ↔ R3NH+ReO4 (o) + NO3 (aq). The order of the uptake(%) for different oxoanions in the presence of 0.01∼5 M HNO3 was Re(VII) > Zr(IV)> Se(VI) > Mo(VI) > Te(VI). The elution study of Tc(VII) revealed 95% and 99% of recovery with 5 M and 7 M HNO3, respectively. The chromatographic separation of Re(VII) from simulated HLLW (28 components of waste solution, SW-11E, JAEA) as well as from mixed solution was accomplished by the stepwise elution techniques using a column packed with TOA-MCs. The Re(VII) ions were effectively eluted with 5 M HNO3, and a relatively large recovery(%) of 98.60% was obtained. Other elements were eluted with H2O and 2 M HNO3. Thus the TOA-xerogel microcapsules are effective for the selective separation of Tc(VII) from HLLW.  相似文献   

16.
The reliability of an 90Sr determination method was tested using an Sr extraction chromatographic resin for strontium isolation. The 90Sr-content in samples of vegetables, soil and water (obtained from Environmental Measurement Laboratory, USA) were determined and the results were controlled by classical methods and by using an anion-exchanger and an alcohol solution of nitric acid for the strontium isolation. These methods were previously tested by determining 90Sr in IAEA 326 and 327 samples of soil. It is shown that the isolation process with Sr resin is simpler and faster than the classical and mixed solvent anion-exchange methods. The efficiency of isolation on a Sr column depends on the resin quantity and separation conditions; and is the highest with a Sr column, compared to the classical and anion-exchange methods. Experimental data and theoretical models were used to calculate the parameters that enable the estimation of optimum dimensions of the column for isolation. A simple relation is proposed for the calculation of breakthrough volume, which defines the sample and eluent volumes for an optimal strontium isolation.</p> </p>  相似文献   

17.
A functional microcapsule was prepared by encapsulating the fine crystalline ammonium tungstophosphate(AWP) in calcium alginate polymer(CaALG).The characterization of AWP-CaALG microcapsule was examined by SEM and EPMA.The adsorption behavior of Cs(I),Rb(I),Sr(II),Pd(II),Ru(III),Rh(III),La(III),Ce(III),Dy(III) and Zr(IV) was investigated by the batch method.The batch experiments were carried out by varying the shaking times,HNO 3 concentration,and initial concentration of metal ions.Relatively large K d values above 10 5 cm 3 /g for Cs(I) were obtained in the range of 0.1-5 M HNO 3,resulting in a separation factor of Cs/Rb exceeding 10 2.In contrast,the K d values of Sr(II),Pd(II),Ru(III),La(III),Dy(III),Ce(III) and Zr(IV) were considerably lower than 50 cm 3 /g.The K d value of Cs(I) decreased in the order of the coexisting ions,H + > Na + >> NH 4 +,and a linear relationship with a slop of about 1 was obtained between log K d and log [NH 4 + ]([NH 4 + ] > 0.01 M).The adsorption of Cs(I) was found to be controlled by chemisorption mechanism,and followed a Langmuir-type adsorption equation.A high uptake percentage of 99.4% for Cs(I) was obtained by using the dissolved solutions of spent fuel from FBR-JOYO(JAEA).  相似文献   

18.
In this communication, we describe a novel method to prepare circular planar 90Sr/90Y sources (? = 16 mm) exploiting the intrinsic properties of the anodized titanium to electro-deposit predicted quantity of 90Sr activity from an aqueous solution. The influences of various experimental parameters such as pH of the electrolyte, applied current density, electrodeposition time and carrier strontium concentration were thoroughly investigated to arrive at a condition resulting optimal deposition of the 90Sr/90Y activity on the substrate. An optimized electrochemical procedure to prepare ~3.7 MBq (~0.1 mCi) of circular planar 90Sr/90Y sources commensurate with regulatory safety requirement has been the positive outcome.  相似文献   

19.
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.  相似文献   

20.
90Sr is a product of nuclear fission, the radioactivity of which can be determined by liquid scintillation counting (LSC). Because the LSC spectra of 90Sr and its daughter 90Y overlap each other, the following methods are usually used: (1) measuring immediately after 90Sr/90Y separation; (2) waiting to reach radioactive equilibrium; (3) adopting the conventional 2-window approach; and (4) using the spectra deconvolution technique. The first one requires 90Sr/90Y separation and immediate measurement; the second one is time-consuming; the third one is valid only for samples with the same quench level as the calibration standard; the last one is somewhat complicated, and in some cases it is not convenient to export the experimental data to some deconvolution software. Therefore, we have developed a modified 2-window approach to rapidly determine 90Sr and 90Y in either equilibrium or disequilibrium at low quench level. The key modification of the approach is to provide an LSC spectrum of pure 90Y with the same quench level as the sample to be determined. This modification eliminates the need to conduct 90Sr/90Y separation for the sample itself, to prepare the quench curves, and to fit the LSC spectra with some deconvolution software.  相似文献   

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