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1.
A99Mo/99mTc generator, system was made with a performed titanium molybdate gel. The irradiation was carried out at a medium neutron flux of 1.5×1013 n cm–2·s–1. The irradiated matrix was loaded on top of a column composed of hydrous zirconium oxide alumina. The elution efficiency and the amount of total technetium per mCi99mTc in the generator eluents have been determined. Molybdenum breakthrough has also been determined and compared with literature values. The influence of the particle size, water content, neutron flux and molybdenum content on the total99mTc-activity has been investigated.  相似文献   

2.
99Mo−99mTc generators were prepared starting from irradiated molybdenum metal instead of MoO3 in order to use reactor irradiation space more economically. The adsorption of molybdenum as sodium molybdate on different kinds of alumina was investigated. The effect of the pH of the column and the aqueous phase concentration of molybdenum were studied and related to the elution yield of99mTc. A study of the radiation damage effect indicated that generators having a high elution efficiency of 90% could be prepared in the 100–600 mCi range. The losses of99Mo were minimized to 10−5-10−4% and those of alumina to 2–5 μg/ml eluate.  相似文献   

3.
Reversed-phase high-performance liquid chromatography with u.v. detection was applied for rapid and sensitive determination of pertechnetate in99Mo/99mTc generator eluates, using a mixture solvent of acetonitrile and 0.04M aqueous acetate buffer (1/1) containing a few volume percentage of 0.5 M tetra-n-butylammonium hydroxide as the mobile phase. Employing a -bondapak C13 column, the TcO 4 species was separated, monitored with absorbance at 254 nm, and observed at the retention time of 3.5 min. The detection limit was found to be 5.2·10–10 g of Tc for each injection. Total Tc contents in the99mTc eluates from clinically-used99Mo/99mTc generator were analyzed by this technique. The99mTc (99Tc) species was separated from the contaminant99Mo. This method was found to be useful for the purification of99mTc (99Tc) as well as the determination of total Tc content.  相似文献   

4.
The results of radiochemical purity measurements for99mTc–S colloid, 90.7±1.4, and99mTc–Sn colloid, 98.9±1.2 obtained by ITLC (SG) with 80% methanol are given. The range of biodistribution normal values for99mTc colloid preparations for animal organs is determined. The results of99mTc–S and99mTc–Sn colloid distribution in liver are 95.4±6.1% and 100,0±5.4%, respectively.  相似文献   

5.
A new technique for the separation of99mTc from low specific activity99Mo is reported. A separation based on the principle of precipitation of99Mo as calcium molybdate has been investigated. On precipitating99MoO 4 2– from alkaline solution as calcium molybdate under controlled conditions, the99mTcO 4 is found to remain quantitatively in the supernatant solution with little carry-over of99Mo. This calcium molybdate (99Mo) could be redissolved and reprecipitated at regular intervals, yielding99mTc quantitatively in aqueous neutral solutions. Calcium molybdate precipitates containing up to 1.5 GBq of99Mo and 130–180 mg of molybdenum were prepared and evaluated. The performance in terms of repeated99mTc separation gave yields of 75–93% with acceptable readionuclidic and radiochemical purity.  相似文献   

6.
Transport of 99mTcO4 ions across TOPO-kerosene based supported liquid membrane was investigated at different concentrations of phosphoric acid as a feed solution and different concentrations of TOPO in the membrane, where 0.9% NaCl aqueous solution was used as a stripping solution. The flux of TcO4 ions across this liquid membrane varied with the concentration of both H3PO4 and TOPO. The best permeability coefficient was obtained at concentrations, [H3PO4] = 3 mole·l–1 and [TOPO] = 0.5 mole·l–1 (P = 2.08·10–9 m2·s–1). The results were utilized for the separation of 99mTc from 99Mo, where a selective and effective separation was obtained since no 99Mo transport across this liquid membrane was noticed while a high rate of 99mTc transport took place.  相似文献   

7.
A novel electrochemical process to avail clinical grade 99mTc from (n,γ)99Mo has been demonstrated. The electrochemical parameters were optimized to maximize the 99mTc yield with minimal 99Mo contamination. 99Mo/99mTc generators containing up to 29.6 GBq (800 mCi) 99Mo were developed and their performance were extensively evaluated for 10 days without changing the operating conditions. Very high radioactive concentration of 99mTcO4 of acceptable quality, commensurate with hospital radiopharmacy requirements could be availed from the system with >90% yield. The compatibility of the product for the formulation of 99mTc labeled radiopharmaceuticals such as 99mTc-DMSA and 99mTc-EC was found to be satisfactory in terms of high labeling yields. The proposed route represents an important step for enhancing the scope of accessing clinical grade 99mTc from low specific activity (n, γ)99Mo.  相似文献   

8.
Neutron irradiated 12-molybdocerate(IV) is evaluated as a column matrix for use in preparation of small chromatographic column type99mTc generators. Greater than 87% of the generated99mTc activity is immediately and reproducibly eluted with passing 10 cm3 of saline or chromated saline solutions through 3.0 g of molybdocerate column bed at flow rates of about 1.0 cm3/min. The elution performance of99mTc does not drastically change with increasing the drying temperature and/or the particles sixe of the column matrix in the range investigated. Saline eluent containing 5·10–5M CrO 4 2– increases the radiochemical purity of the eluate to >98% TcO 4 . Radionuclidic and chemical purities of the eluates satisfy the specifications for use in nuclear medicine.  相似文献   

9.
The preparation of insoluble 12-molybdocerate(IV) from99Mo of low specific activity, produced by thermal neutron irradiation of MoO3, is described. Samples of the material are dried at 50, 100 and 200°C and used as column matrices from which the generated99mTc activity is periodically eluted with saline solution or saline solution containing 5·10–5M K2CrO4 as an oxidant. The elution yields of99mTc are high and reproducible (95–81%) with radionuclidic purity 99.98%. Both chemical and radiochemical purity (as TcO 4 ) of the eluates decrease with increasing drying temperature of the column matrix. Using chromated saline solution as eluent improves the radiochemical purity of the99mTc eluate.  相似文献   

10.
The feasibility of using tetragonal nano-zirconia (t-ZrO2) as an effective sorbent for developing a 99Mo/99mTc chromatographic generator was demonstrated. The structural characteristics of the sorbent matrix were investigated by different analytical techniques such as XRD, BET surface area analysis, FT-IR, TEM etc. The material synthesized was nanocrystalline, in tetragonal phase with an average particle size of ~7 nm and a large surface area of 340 m2 g?1. The equilibrium sorption capacity of t-ZrO2 is >250 mg Mo g?1. The present study indicates that 99Mo is both strongly and selectively retained by t-ZrO2 at acidic pH and 99mTc could be readily eluted from it, using 0.9% NaCl solution. A 9.25 GBq (250 mCi) t-ZrO2 based chromatographic 99Mo/99mTc generator was developed and its performance was repeatedly evaluated for 10 days. 99mTc could be eluted with >85% yield having acceptable radionuclidic, radiochemical and chemical purity for clinical applications. The compatibility of the product in the preparation of 99mTc labeled formulations such as 99mTc-EC and 99mTc-DMSA was evaluated and found to be satisfactory.  相似文献   

11.
The determination of α- and pure β-emitting impurities in99Mo/99mTc generator eluates before application is discussed. It is shown that α-emitters in ≥10 mCi eluates can be determined in a proportional counter or an α-spectrometer within 30 min with detection limits lower than the European Pharmacopoeia limit (10−7% of the main activity).89Sr and90Sr are determined after chemical separation, consisting of ion exchange to separate the main activity (TcO 4 ), shaking with charcoal to separate colloidal particles containing Mo and precipitation of Sr as oxalate or sulfate. The precipitate is measured in a low-level counter. For eluates with an activity of ≥10 mCi the detection limits are one order of magnitude lower than the activity limit given by the European Pharmacopoeia for90Sr (6×10−6% of the main activity). The time needed for chemical separation and activity measurement is about 30 min.  相似文献   

12.
A column-extraction generator based on the adsorption of alkaline sodium molybdate on an acid alumina column is described. Generators containing 1 to 3.2 g of molybdenum /99Mo/ absorbed on 12–15 g of acid alumina, with activities ranging from 0.52 to 5.2 GBq /14 to 140 mCi/, have been prepared and evaluated. The results indicate that99mTc can be quantitatively eluted from such columns with about 10 ml of MEK. The yields were found to be in the range of 70 to 90% over 3–6 days.  相似文献   

13.
The subject of this paper is to explore the possibility to obtain 99mTc from activation of 98Mo, using the TRIGA Mark II low flux research reactor (Vienna, Austria). Irradiation of both natural and enriched in 98Mo molybdenum oxides was compared. Aims of this work included the determination of neutron fluxes and 98Mo(n, γ)99Mo reaction effective cross section in the TRIGA Mark II reactor irradiation channels, calculation of 99Mo specific activities, determination of optimal irradiation conditions for the subsequent 99mTc separation from MoO3 targets using concentrating technologies.  相似文献   

14.
A modified99Mo–99mTc gel generator is described. The present generator uses an insoluble zirconium molybdophosphate (ZrMP) gel tagged with99Mo. Molybdenum-99 is chemically combined in the gel structure and cannot be eluted from the matrix. The presence of phosphate increases the chemical stability of the gel and decreases the molybdenum breakthrough. The prepared gel is sufficiently porous to permit ready diffusion of99mTcO 4 which can be cluted with saline in yields of up to 90%. The gel was found to contain 25.1% Mo, 21.9% Zr, and 0.7% P in a molar ratio of 1.09:1.0:0.09, respectively. The high molybdenum content of the gel allows the use of cheap, non-polluting (n, )99Mo. The eluted99mTc was of high purity and can be used for medical and pharmaceutical applications.  相似文献   

15.
A method is discussed for separating99mTc from99Mo by dissolution and reprecipitation of CaMoO4 containing99Mo-99mTc.99mTc can be obtained successfully with a yield of about 80% and with a radionuclidic purity as high as over 99.7%. On the other hand, by agitating Ca99 MoO4 solid with 0.9% NaCl aqueous solution,99mTc can directly be obtained with a yield of about 30% without any impurities.  相似文献   

16.
Distribution coefficients of technetium and ruthenium are determined under different conditions with CCl4, cyclohexanone, and 5% tri-isooctylamine (TIOA)/xylene. A method for analyzing99Tc in environmental samples has been developed by solvent extraction in which the valences of technetium and ruthenium are controlled with H2O2 and NaClO. Technetium and ruthenium which are oxidized to TcO 4 and RuO 4 by NaClO are separated by extraction with CCl4 at pH 4. The RuO 4 is reduced to low valence and technetium is kept in the TcO 4 state with H2O2. Technetium, ruthenium, and other nuclides are subsequently separated by solvent extraction with cyclohexanone and 5% TIOA/xylene. The decontamination of the procedure is 1.35·105 for103Ru and 1.66·105 for110mAg. The chemical yield of technetium-99 is 55%.On leave from Institute of Atomic Energy, Beijing, China  相似文献   

17.
Adsorption and desorption of95Zr−95Nb,99Mo,103Ru,132Te and239Np in a HCl-alumina system were studied in order to purify99Mo and132Te obtained by the cation-exchange separation of fission products and to prepare highly pure99mTc and132I generators.99Mo and132Te, of which radionuclidic purity was over 99.99% and 99.999%, respectively, could be obtained by passing the cation-exchange separated Mo and Te fractions through alumina columns, by washing with HCl and finally by eluting99Mo with 1M NH4OH and132Te with 3M NaOH. In order to raise the recovery of99Mo and132Te from the alumina columns, they should be eluted as quickly as possible after the adsorption. The direct use of the alumina column containing99Mo or132Te as the generator allowed milking of99mTc or132I, of which radionuclidic purity was over 99.999%. Milking yields of99mTc with 0.1M HCl and132I with 0.01M NH4OH were 77% and 90%, respectively. The latter value was much higher than that in usual performance of the generator.  相似文献   

18.
The adsorption behaviour of99Mo in the form of molybdate and of99mTc in the form of pertechnetate on hydrated titanium dioxide was investigated at different molarities of hydrochloric acid. The adsorption capacity of molybdate on hydrated TiO2 is higher than on Al2O3. A99mTc-generator is suggested. This generator is based on the adsorption of (99Mo) molybdate on hydrated TiO2, at acidities of 0.05–0.1M. HCl.99mTc is eluted with 0.9% NaCl. Radionuclidic, radiochemical and chemical purities of the eluates were checked. This generator seems to have a great potential as compared to the traditional alumina generators.  相似文献   

19.
A radiochemical method has been developed for the determination of99Tc in low-level radioactive, waste from nuclear facilities, using99mTc as an internal tracer. Radioactive contaminants were removed by carrier hydroxide precipitation and chelating extraction with NaDDC/CHCl3 system at pH 4. The final technetium was chelated with NaDDC in 3N HCl solution and extracted selectively into chloroform. The average of radiochemical recovery for various types of LLW sample is about 90%. The decontamination factors for most radioactive nuclides are higher than 105. The detection limit for99Tc in a sample of about 10 g is 0.17 pCi/g (6.5 Bq·kg–1) for a 100-minute count.  相似文献   

20.
The effect of increased content of copper on the radiochemical composition of three skeletal imaging agents:99mTc(Sn)-methylene diphosphonate (MDP),99mTc(Sn)-pyrophosphate (PYP) and99mTc(Sn)-2,3-dicarboxypropane-1, 1-diphosphonate (DPD) was observed only in the case of99mTc(Sn)-MDP. It was found that the radiochemical purity of this radiopharmaceutical falls to about 50% when the copper content reaches about 10–5 mol dm–3. According to the results of radiochemical and biological analyses, it could be concluded that with the increase of copper content, the content of free pertechnetate rises, too. The two other radiopharmaceuticals,99mTc(Sn)-PYP and99mTc(Sn)-DPD, were found to be stable under the given experimental conditions.  相似文献   

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