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1.
A theoretical investigation of the feasibility of producing a molybdenum-99: technetium-99m generator from MoO3 using a 30 kW Miniature Neutron Source Reactor (MNSR) has been made. At the rated thermal neutron flux of 1012 n·cm–2·s–1 and irradiation time of 2.5 hours per day, for 8 consecutive days, activities of 7.1 mCi and 5.2 mCi were calculated for99Mo and99mTc, respectively. A 20 g sample of 99.5% chemically pure MoO3 was used. The advantage for operating the reactor for 8 days instead of 6 days would be an increase of 11.4% and 15.5%, respectively, in the amount of99Mo and99mTc produced. it is calculated that an optimum irradiation scheme is achieved when the reactor is operated for an extended period of 5 hours a day for 5 days a week at a lower flux level of 7.5·1011 n·cm–2·s–1. With this optimum operation scheme, there would be an increase in the weekly specific activity of 36% and 37.9% for99Mo and99mTc, respectively.  相似文献   

2.
The Tc budget in several ROTOP-generators was determined by neutron activation analysis (NAA) and UV-spectroscopy. The complete procedure included the preparation of the generator, elution cycle in 24 to 72 h intervals and evaporation of the eluates to dryness. The samples were aliquoted, irradiated in the reactor and analyzed via99Tc(n, n')99mTc99Tc reaction as well as by UV-absorption due to pertechnetate. The most reliable method proved to be NAA including chemical separation from24Na by ion exchange after the complete decay of38Cl. The detection limit was 50 ppb (3 ng Tc), compared with the total amount of several 10–5 g down to 10–7 g Tc in the system and its fractions. The mass balance and the elution profiles obtained correspond very well to the theoretical values. The results permit further quantitative considerations on both elution kinetics and the generator system.  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 nuclear properties of99mTc radionuclide are ideal for organ imaging. Study of the technetium transport across supported liquid membranes has been performed to get data for its separation from other elements. Tri-n-octylamine diluted in xylene was used to constitute the liquid membranes, supported in polypropylene microporous films. Stripping on the product solution side was performed with dilute NaOH solutions. The effect of sulphuric acid, nitric acid and hydrochloric acid in the feed on transport of99mTc as TcO 4 ions has been studied. The permeability of the given ions determined from kinetic activity data has been found to be in the order of PH2SO4>PHCl>PHNO3. The flux values have been calculated based on this permeability data. The increase in carrier concentration has shown an increase in flux and permeability values to a given optimum concentration. The increase in temperature has been found to reduce the transport of Tc ions. The optimum conditions for transport of99mTc for the given acid concentration have been determined. Mechanism of Tc ion transport has also been provided based on chemical reactions involved at the membrane interfaces and uptake of Tc ions by the membrane. MoO 4 2– ions do not permeate through membrane under optimum conditions of transport for TcO 4 2– ions from H2SO4 solution.  相似文献   

5.
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   

6.
The authors report here a new approach for making99mTc generators based on neutron irradiation of metallic molybdates and direct elution eliminating intermediate chemical processing steps. This approach tested using zirconium molybdate was found to yield99mTc with good yield and purity. This seems to be the simplest way of making column type99mTc generator even using low flux reactors and merits further detailed evaluation.  相似文献   

7.
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   

8.
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   

9.
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   

10.
The cross-sections for formation of metastable state of 99Tc (99mTc, 140.511 keV, 6.01 h) through natRu(n,x)99mTc reaction induced by 13.5 MeV and 14.8 MeV neutrons were measured. Fast neutrons were produced via the 3H(d,n)4He reaction on the K-400 neutron generator. Induced gamma activities were measured by a high-resolution gamma-ray spectrometer with a high-purity germanium (HpGe) detector. Measurements were corrected for gamma-ray attenuations, dead time and fluctuation of neutron flux. Data for natRu(n,x)99mTc reaction cross sections are reported to be 9.6±1.5 and 9.2±1.1 mb at 13.5±0.2 and 14.8±0.2 MeV incident neutron energies, respectively. Results were compared with the data by other anthors.  相似文献   

11.
The chemical condition of99mTc eluate obtained from a99Mo-99mTc generator is a function of the source, time elapsed after elution and age of the eluate. The radiochemical purity and stability of99mTc labeled MAb-170 (Tru-Scint®ADTM, photoactivated monoclonal antibody kit) preparations was evaluated comparing pertechnetate source of known age and elution history. The effect of H2O2, a radiolytic impurity in99mTc eluates, on the active kit components stannous ion and photoactivated MAb and radiolabeling, yield has been investigated. The lyophilized Tru-Scint® ADTM kit has been labeled with 20 to 80 mCi in 0.5 to 4.0 ml of Sodium Pertechnetate99mTc Injection, USP. The eluates were obtained from three brands of generators and used up to six hours after elution. The kits were reconstituted either with Sodium Pertechnetate99mTc Injection, USP or Sodium Chloride Injection, USP, 0.9% containing known amounts of H2O2. The reconstituted kits were analyzed for radiolabeling yield and radiochemical impurities, stannous ion and protein sulfhydryl group. The results indicated that the radiolabeling yield is a function of both the chemical condition of99mTc eluate, generator brand and the radiolabeling parameters like reconstitution volume and activity. The observed radiolabeling yield differences did not depend on the amount of chemical technetium in the eluate. The major radiochemical impurities at 15-minute post labeling have been identified as the99mTc-buffer complex and column adsorbed reduced99mTc (99mTc-Ad) species and not the unreduced99mTcO 4 .  相似文献   

12.
A procedure for preparation of a sterile closed system generator for99mTc based on conversion to zirconium molybdate of99Mo produced by neutron activation is reported. The generator is sterilized by autoclaving.99mTc is eluted using 0.9% NaCl with high yield and purity in successive elutions.  相似文献   

13.
Transport of99mTc across tri-n-butylphosphate (TBP) kerosene oil supported liquid membranes (SLM) has been studied under various conditions. Presence of dichromate ions helps avoid activity scavenging effects. Concentration increase of TBP, the complexing carrier used in the present study has a positive effect on flux (J) and permeability (P) of these ions, as up to 2.87M there is an increase in J and P values. HCl concentration in the feed solution increases J and P with their maximum values at 2.5–3.0M HCl in the feed. Above this concentration there is a decrease in flux and permeability of99mTc(VII) ions. The given ions are stripped with LiCl or NaCl solutions but more with NaOH. The optimum conditions of transport of the given ions are 2.5M HCl concentration in the feed, 2.87M TBP concentration in the membrane and 1M NaOH concentration in the strip solution. Equations have been developed to indicate the relation between flux, J, viscosity, of TBP in organic membrane phase, temperature, T, [H+], in the aqueous feed solutions and Tc ion concentration in the feed solution. Based on P, the values determined from liquid membrane experiments, the quantitative flux values of Tc(VII) ions were also determined as a function of TBP concentration in the membranes, and HCl and Tc concentration in the feed solution using the given equations. This experimental technique provides quantitative results from trace level activity transfer experiments.  相似文献   

14.
The radiochemical purity of the three osteopatic ligands:99mTc(Sn)-PyP,99mTc(Sn)-DPD and99mTc(Sn)-MDP has been determined by gel chromatography on Sephadex. The results of the analyses strongly depend on the composition of the eluent. The dilution effect of pure saline as eluent was observed in all the preparations examined. The most sensitive was found to be99mTc(Sn)-PyP. The retention of99mTc activity bound to the gel matrix (99mTc-hydrolyte) was over 30%. The diphosphonates were found to be more stable (retention 10–15%). The retention is substantially lower, i.e. a high recovery of the labeled complexes is obtained when the eluent contains the ligand. The best results are obtained when the eluent contains the same concentrations of ligand and reductant as in the labeled complex. There was no significant difference in the behavior of the given radiopharmaceuticals prepared as a fresh solution and in the freeze-dried kit.  相似文献   

15.
Complex forming conditions of 8-hydroxyquinoline with99mTc have been specified.99mTcO4 has been reduced by SnCl2 to a lower oxidation level. Labeling yields have been determined by ITLC (Instant Thin Layer Chromatography). Various parameters, such as pH, temperature, reaction time, ligand to SnCl2 ratio, which can affect the labeling yields, have been determined. Optimum conditions are 4–7 for pH; 15–20°C (room) for temperature; 1.55 for ligand to SnCl2 ratio and 5 min for reaction time.  相似文献   

16.
A procedure for preparation of 99Mo/99mTc radioisotope generator based on low specific activity neutron activated 99Mo was developed. Aluminum molybdate(VI)-99Mo of high Mo(VI) content (~?364 mg/g Al99Mo) was prepared by mixing low specific activity molybdate(VI)-99Mo and aluminum mixture solution with isoamyl alcohol. Al99Mo gel matrix was precipitated when the pH of the mixture solution was raised to ~?5 by addition of NaOH to the mixture. Radiometric measurements indicate the strong fixation of Molybdate(VI)-99Mo species in the form of the sparingly insoluble Al99Mo gel matrix. The prepared AlMo gel matrix was physiochemically characterized. Al99Mo gel matrix was used as a base material for preparation of 99Mo/99mTc generator. The 99mTc eluted from 99Mo/99mTc radioisotope generator was found to have relatively high elution yield (84?±?2.3%), radionuclidic (≥?99.99%), radiochemical (98.1?±?0.9%) and chemical purity.  相似文献   

17.
Carrier-free99mTcO4 eluated from clinical99Mo/99mTc generators was examined to determine its specific activity. The observed specific activity was found to be always lower than the calculated value based on the99Mo–99mTc–99Tc decay scheme data. These results could be explained in terms of existence of excess Tc loaded onto generator column.  相似文献   

18.
The labelling of 1,3-n alkylpropanedithiols and of 15-/1,3-dimercapto 2-propyl/ pentadecanoic acid by99mTc has been performed by an exchange reaction with the hexachlorotechnetate ion99mTcCl 6 2– and by reduction of99mTcO 4 with Sn/II/ in the presence of the ligand. The biological distribution of the exotechnetium complexes obtained by the latter method in mouse does not reveal a high tropism of these labelling compounds in relation to a particular tissue.  相似文献   

19.
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   

20.
The methods used for control of radiochemical purity of99mTc-MDP are presented. TLC method on silica gel, developed with methanol and acetone (11 v/v), was convenient for determination of99mTcO 4 with the content of 2.6±1.2%. The reliable results on detection of99mTc hydrolyzate (2.2±1.3%) and for another99mTc-MDP complex (13.2±2.8%) were obtained by application of ITLC (SA), developed with Sn-MDP. By Sephadex G-25 column chromatography (1.5 cm×5 cm) the separation of99mTcO 4 was not achieved. The range of normal99mTc-MDP biodistribution values in the organs of experimental animals have been determined. The mean value of bone distribution was 8.4±1.13%/g, in muscles 0.071±0.033%/g, while uptake in liver and kidneys was below 5%. Chi-square test and P show that the results on biodistribution of99mTc-MDP in liver, bones and muscles are arranged around their mean values, which is statistically allowed.  相似文献   

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