Classifications

• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21G—CONVERSION OF CHEMICAL ELEMENTS; RADIOACTIVE SOURCES
  • G21G1/00—Arrangements for converting chemical elements by electromagnetic radiation, corpuscular radiation or particle bombardment, e.g. producing radioactive isotopes
  • G21G1/001—Recovery of specific isotopes from irradiated targets
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
  • C01F11/00—Compounds of calcium, strontium, or barium
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21G—CONVERSION OF CHEMICAL ELEMENTS; RADIOACTIVE SOURCES
  • G21G1/00—Arrangements for converting chemical elements by electromagnetic radiation, corpuscular radiation or particle bombardment, e.g. producing radioactive isotopes
  • G21G1/001—Recovery of specific isotopes from irradiated targets
  • G21G2001/0094—Other isotopes not provided for in the groups listed above
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S422/00—Chemical apparatus and process disinfecting, deodorizing, preserving, or sterilizing
  • Y10S422/903—Radioactive material apparatus

Definitions

• This invention relates to a novel process for the production of radioactive barium-137m.
• this invention relates to a novel process for the production of radioactive barium-137m in high yields.
• a further aspect of this invention is directed to a novel process for the production of radioactive barium-137m which can be obtained in a high degree of purity.
• Barium-137m the daughter nuclide of cesium-137, is known to be an extremely convenient isotope for medical research and diagnosis. It is particularly suitable for the study of vascular dynamics, such as blood flow rates. Due to the relatively short half-life of 2.6 minutes, barium-137m can be safely administered in multicurie quantities with a very limited radiation dose. This is of particular importance when a clear, sharp scanning picture is desired. The short half-life of barium-l 37m also renders it of interest for educational purposes. For example, students can measure nuclear properties in a limited classroom period, using a non-shielded, low activity barium-137m generator. Barium-137m can also be used for various other purposes where a short half-life is desired.
• 1,392,506 used cupric ferrocyanide and recovered 12-20 percent barium-137m in barium nitrate solution.
• barium-137m is not recoverable in physiological isotonic saline solution, water or dilute hydrochloric solution; thus, requiring the additional chemical treatment of the eluent for an intravenous injection into a human body or for other experiments.
• the additional chemical step is, of course, not desirable for barium-137m since it decays rapidly.
• the recovery of barium-137m from the known generators is poor.
• Another object of this invention is to provide a more efficient method for producing radioactive barium-137m.
• Another object of this invention is to provide a process for preparing radioactive barium-137m in a high degree of purity and by an extremely reproducible and simple process.
• An object of this invention is to produce radioactive barium-137m by a method wherein the degree of recovery is high.
• a further object of this invention is to provide a process for preparing radioactive barium-137m of a high degree of purity and which is acceptable for medical research and diagnosis.
• a still further object of this invention is to provide a sterile, physiological, saline solution containing radioactive barium- 137m.
• Radioactive barium-137m prepared by the process of this invention is obtained in a very high degree of purity and is therefore suitable for use in medical research and diagnosis.
• this process is extremely simple and rapid providing a high recovery of barium.
• the eluted barium isotope is free of undesirable ions and organic agents. Additionally, since further chemical purification of the eluent is unnecessary, full advantage can be taken of the relatively short half-life of this isotope.
• barium-137m is obtained from its parent element cesium-137.
• the cesium-137 is commercially available and is obtained as the fission product of uranium.
• the irradiation of the uranium target material is a well known technique and can be effected by placing uranium in the irradiation zone of a nuclear reactor, particle generator or neutron isotopic source.
• Purification of the cesium-137 prior to its use in the instant process can also be effected by known chemical methods, thereafter, the cesium-137 is contacted with a cobalt (ll) ferrocyanide, from which the daughter isotope, barium-137m can be eluted.
• the cobalt ferrocyanides which have been found to be useful in the present invention, are those having the formula:
• M represents nickel, zinc, iron (11) and copper (II).
• copper (II) cobalt ferrocyanide is the preferred substrate for the cesium-137.
• a generator containing the cesium-137 can be conveniently prepared by contacting the cobalt ferrocyanide with the irradiated target materials and thereafter loading it onto a column.
• this can be done by dissolving the cesium-137 in a suitable solvent and contacting the resulting solution with the cobalt ferrocyanide.
• the cobalt ferrocyanide, on which is adsorbed the cesium-137 solution be heated at a temperature of from about 50 C. to about 100 C. for a period of at least about 2 minutes.
• the heating step can be omitted.
• cesium-137 it is preferred to employ the heating step and avoid its presence in the eluent.
• aqueous solution can be employed to load the cesium-137 onto the cobalt ferrocyanide, it is preferred to employ a slightly acidic, aqueous solution. Suitable solvents therefor include water, or an aqueous solution of an inorganic acid, such as 0.1M hydrochloric acid. Hydrochloric acid is particularly preferred since the resulting cesium breakthrough is minimized. For instance, when 0.1M nitric acid was employed the cesium breakthrough was found to be about 0.3 percent. However, when 0.1M hydrochloric acid was used, the breakthrough was reduced to about 0.01 percent.
• the recovery of barium-137m from the generator decreases with time from about percent to about 20 percent over a 2 month period.
• a reducing agent such as graphite, carbon black, charcoal, and the like
• the reducing agent is usually employed in an amount of from about 5 to about 60 percent and more preferably from about 30 to 40 percent based on the weight of the cobalt ferrocyanide employed.
• a filter should be employed to prevent cesium-137 from contaminating the eluent. While a variety of filtering devices can be employed, it has been observed that any anion exchange such as hydrous zirconium oxide is ideally suited for this purpose.
• the anion exchanger can be placed in the generator below the ferrocyanide so as to filter any undesirable cesium-137.
• barium-137m generator in in preparing a barium-137m generator from which it is desired to obtain a highly pure eluent, it is essential to heat the loaded substrate, employ a reducing agent, and use filtering means to eliminate any traces of cesiuml 37.
• the purity of the barium-137m solutions obtained from such a generator is high, containing approximately 2 X 10 percent cesium-137, and less than 1 part per million of iron, cobalt, copper and cyanide ions.
• the process of this invention is suitable for the production of barium-137m for educational purposes.
• cesium-137 breakthrough be controlled, nor a reducing agent or filtering means be employed.
• reducing agent or filtering means be employed.
• the substrate containing the cesium-137 is prepared it is then transferred to an appropriate elution system such as a column, or vessel, preferably glass, or other inert material.
• an appropriate elution system such as a column, or vessel, preferably glass, or other inert material.
• the system is washed with water and the supernatant liquid is allowed to drain or be removed by filtration or decantation.
• the substrate is then washed with isotonic saline and is ready for eluting.
• the process of the present invention provides a simple method for the preparation of barium- 137m in a high degree of efficiency.
• recovery of barium-137m can be effected with isotonic saline in efficiencies as high as 90 and higher, without dissolution of the substrate or removal of any significant amounts of cesium from the substrate.
• EXAMPLE 1 This example illustrates the preparation of highly pure barium- 1 37m such as would be required for use as a medical diagnostic agent.
• the cupric form of cobalt (II) ferrocyanide which adsorbs Cs-137 and elutes barium 137m was prepared in the following manner. 10 milliliters of 10 percent cupric sulphate in 0.1 molar hydrochloric acid was added to 1 milliliter of a commercially available potassium cobalt (I1) ferrocyanide. The slurry was heated for 30 minutes at about 80 C. After cooling, the supernate was decanted and the solid phase was washed three times with water by decantations. To the cupric form of cobalt (II) ferrocyanide thus prepared, 1 millicurie of Cs- 1 37 in 0.1 molar hydrochloric acid was added.
• the slurry was heated for about 30 minutes at 85-90 C. and allowed to cool for another 30 minutes. Then, 0.4 grams of graphite particles (20-50 mesh) was added and mixed with the slurry. The mixture was transferred into the column containing the cesium-137 filter and the column was washed with 100 milliliters of physiological saline solution. Both ends of the column were sealed with rubber septums and aluminum crimp caps. One end of the generator was connected to a source of physiological saline solution and another end to a receiving bottle using a proper tubing and needles. A millipore filtering unit was attached to the tubing prior to the solution flowing into the receiving bottle. Ba-l37m was obtained in the receiving bottle by washing the column with physiological saline solution.
• Table 1 shows the adsorptionelution characteristics of the Ba-l 37m generator.
• a hundred microcurie of Cs-l37 activity was adsorbed on the cupric form of cobalt (11) ferrocyanide in the same manner as described earlier. Then, a small portion of the substrate containing 1 microcurie of Cs-137 was transferred onto a small sized filtering unit such as Swinex filtering unit manufactured by Millipore Corporation. The radioactivity was adjusted to a desired level by counting on a detector such as a gamma ray scintillation counter or G. M. counter. The filtering unit was then sealed, connected with a syringe containing an eluent, and eluted. Table II shows the elution characteristics of the generator. When physiological saline solution is used as the eluent, an occassional treatment with acid, for example once each 2 month period with 0.1 molar hydrochloric acid, is required to maintain a high Ba-137m recovery.
• a radioactive isotope generator comprised of, in combination,
• M [CoFe(CN) wherein M represents a member selected from the group consisting ofnickel, zinc, iron (11) and copper (II) and deposited therein cesium-137m,
• radioactive isotope generator of claim 1 wherein said cobalt ferrocyanide is cupric cobalt (11) ferrocyanide.
• radioisotope generator of claim 1 wherein said sub- 5 strate is contained on a filter which selectively retains cesiumi 6.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Inorganic Chemistry (AREA)
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• Chemical Kinetics & Catalysis (AREA)
• Life Sciences & Earth Sciences (AREA)
• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• High Energy & Nuclear Physics (AREA)
• Medicines Containing Antibodies Or Antigens For Use As Internal Diagnostic Agents (AREA)
• Solid-Sorbent Or Filter-Aiding Compositions (AREA)

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Cited By (3)

Citations (4)

• 1968
  • 1968-08-28 US US755820A patent/US3663177A/en not_active Expired - Lifetime
• 1969
  • 1969-08-14 GB GB1231159D patent/GB1231159A/en not_active Expired
  • 1969-08-26 DE DE1943416A patent/DE1943416C3/de not_active Expired
  • 1969-08-26 JP JP44066948A patent/JPS4928878B1/ja active Pending
  • 1969-08-26 CH CH1299969A patent/CH516335A/fr not_active IP Right Cessation
  • 1969-08-27 BE BE738059D patent/BE738059A/xx unknown
  • 1969-08-27 SE SE11883/69A patent/SE360387B/xx unknown
  • 1969-08-28 FR FR6929528A patent/FR2016532A1/fr not_active Withdrawn
  • 1969-08-28 NL NL696913171A patent/NL149316B/xx unknown

Patent Citations (4)

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