阅读说明：本技术 一种利用加速器辐照富集100Mo生产99mTc的方法 (Irradiation enrichment by accelerator100Mo production99mTc method ) 是由 陈德胜 秦芝 吴晓蕾 黄清钢 王洁茹 于 2020-06-29 设计创作，主要内容包括：本发明公开了一种利用加速器辐照富集<Sup>100</Sup>Mo产生<Sup>99m</Sup>Tc的方法。该方法主要包括以下几部分：(1)制备钼靶；(2)利用质子束辐照钼靶；(3)利用高温氧化法将钼锝金属转换成氧化物；(4)利用生理盐水等溶剂选择性溶解Tc<Sub>2</Sub>O<Sub>7</Sub>；(5)利用色谱柱纯化<Sup>99m</Sup>Tc；(6)<Sup>100</Sup>Mo的回收。利用该工艺流程能够制备出符合医用标准的含<Sup>99m</Sup>Tc的溶液,并能实现<Sup>100</Sup>Mo的高效循环利用。(The invention discloses a method for enriching by using accelerator irradiation 100 Mo production 99m Tc. The method mainly comprises the following steps: (1) preparing a molybdenum target; (2) irradiating the molybdenum target with a proton beam; (3) converting molybdenum-technetium metal into oxide by high-temperature oxidation; (4) selective dissolution of Tc using solvents such as physiological saline 2 O 7 (ii) a (5) Purification by means of a chromatographic column 99m Tc；(6) 100 And (4) recovering Mo. The process flow can be used for preparing the medical solution 99m Tc solution and can be realized 100 And (4) high-efficiency recycling of Mo.)

1. Irradiation enrichment by accelerator¹⁰⁰Mo production^99mA method of Tc, comprising:

1) preparing a high-power metal molybdenum target;

2) irradiating the high-power metal molybdenum target obtained in the step 1) to obtain^99mTc；

3) Conversion of molybdenum and technetium metals to MoO by high temperature oxidation₃And Tc₂O₇And selectively dissolve Tc₂O₇Filtering the obtained solution to obtain a filtrate which is a technetium solution containing a small amount of molybdenum, and collecting the obtained filter residue;

4) the technetium solution containing a small amount of molybdenum obtained in the step 3) is carried out by utilizing an acidic alumina chromatographic column^99mPurifying Tc;

5) carrying out the filtration residue obtained in the step 3)¹⁰⁰And (4) recovering Mo.

2. The method of claim 1, wherein: in the step 1), the material for forming the high-power metal molybdenum target is enriched metal molybdenum 100, the chemical purity is more than 99.9 percent,¹⁰⁰the abundance of Mo is more than 80 percent;

the high-power metal molybdenum target is circular or elliptical; the thickness is 200-1000 μm;

the target chamber is a back plate water-cooling target.

3. The method according to claim 1 or 2, characterized in that: in the step 1), the method for preparing the high-power metal molybdenum target is a high-temperature sintering method;

the density of the high-power metal molybdenum target is 8.5mg/cm³-10 mg/cm³(ii) a The thermal conductivity coefficient is 100W/(m DEG C) to 146W/(m DEG C).

4. The method of claim 3, wherein: in the high-temperature sintering method, the temperature is higher than 1200 ℃; the time is 1-6 h.

5. The method according to any one of claims 1 to 4, wherein: in the irradiation step in the step 2), the irradiation accelerator is a proton accelerator;

the energy of the proton beam is 16MeV-25 MeV; specifically 20.9 Mev;

the flow intensity is 1 muA-2000 muA; specifically 1.0 muA;

the irradiation time is more than 1 hour; in particular 1-10 hours.

6. The method according to any one of claims 1 to 5, wherein: in the step 3), the temperature is 750-900 ℃ in the high-temperature oxidation step; in particular 800 ℃;

the oxidant is oxygen with purity more than 99%;

the flow rate of the oxygen gas is 10mL/min-500 mL/min; specifically 40 mL/min;

the oxidation time is 10-60 min; specifically 30 min.

7. The method according to any one of claims 1 to 6, wherein: in the selective dissolving step of the step 3), the solvent is at least one selected from water, a weakly alkaline solution and normal saline;

the weak alkaline solution is at least one of ammonia water and sodium hydroxide aqueous solution;

the concentration of the weak alkaline solution is less than 0.2 mol/L;

the dissolving temperature is 25-80 ℃; in particular 60 ℃.

8. The method according to any one of claims 1 to 7, wherein: the step 4) of purifying comprises the following steps: firstly, adjusting the pH value of the technetium solution containing a small amount of molybdenum to 4-5, and leaching on a chromatographic column;

the regulator used in the step of regulating the pH value is a nitric acid or hydrochloric acid solution; the concentration of the regulator is 0.2-1.0 mol/L;

the chromatographic column is an acidic alumina column;

the length of the chromatographic column is 2cm-5cm, and the diameter of the chromatographic column is 0.5cm-1.5 cm;

in the chromatographic column, the pH value of the acidic alumina is 4-5; in particular 4.5; the grain diameter is 100um-250 um;

the eluent is normal saline;

the dosage of the eluting agent is 2-10 column volumes;

the leaching speed is 0.5mL/min-2.0 mL/min.

9. The method according to any one of claims 1 to 8, wherein: the step 5) of recovering comprises the following steps:

dissolving the filter residue with ammonia water, evaporating to dryness, and reducing at high temperature to obtain metal¹⁰⁰Mo。

10. The method of claim 9, wherein: in the dissolving step, the concentration of ammonia water is 1-13 mol/L;

in the step of drying by distillation, the temperature is 50-90 ℃;

the high-temperature reduction step comprises: under the condition of the existence of carrier gas, firstly carrying out low-temperature conversion and then carrying out high-temperature reduction;

specifically, in the low-temperature conversion step, the temperature is firstly increased to 80-100 ℃, the temperature is kept for 20-40min, and then the temperature is increased to 300-500 ℃;

specifically, the temperature is firstly increased to 90 ℃ and is preserved for 30min, and then the temperature is increased to 400 ℃ and is preserved for 0.5 h;

in the high-temperature reduction step, the temperature is firstly preserved for 50-70min at the temperature of 500-; specifically, the temperature is preserved for 60 minutes at 600 ℃ and then preserved for 3 hours at 1000 ℃;

the carrier gas is hydrogen-argon mixed gas; particularly hydrogen-argon mixed gas with the volume percentage of 2-4% of hydrogen; the volume percentage of the hydrogen is specifically 4%;

the gas flow of the carrier gas is 40-200 mL/min.

Technical Field

The invention belongs to the field of manufacturing of medical radioactive isotopes, and particularly relates to irradiation enrichment by using an accelerator¹⁰⁰Mo production^99mTc.

Background

^99mTc is β^-The decaying nuclide has a half-life period of 6.01h, can emit gamma rays with energy of 140.5keV, is the medical radioactive diagnostic nuclide which is widely applied to the whole sphere at present, and accounts for more than 80 percent in nuclear medicine development. With the increase of the medical level, the medical treatment level,^99mthe demand for Tc is increasing.

Preparing medical use at home and abroad^99mTc, obtained mainly by neutron irradiation of highly enriched uranium in a reactor⁹⁹Mo, then separating and purifying by a wet method to obtain⁹⁹Mo, finally assembled into Mo-technetium generator, through β^-Decay to obtain^99mTc (²³⁵U(n,f)⁹⁹Mo→^99mTc). The whole process is complex in operation, high in cost, low in utilization rate of uranium and capable of generating a large amount of radioactive wastes. In addition, medical isotopes currently used in the domestic market^99mTc mainly depends on import, but in the past decades, most reactors for producing medical isotopes worldwide face the problems of shutdown, reconstruction and the like, which causes the phenomenon that hospitals face lack of technetium, and seriously restricts the development of nuclear medicine departments in China. Accelerator direct irradiation Mo production relative to reactor^99mTc, low construction cost, simple operation of the dry separation process and high utilization rate of the molybdenum target. Thus producing medical isotope by using accelerator^99mTc is a new route that can replace reactor production.

Is currently directed to^99mThere are many methods for separating and purifying Tc, mainly chromatography, extraction and sublimation. The chromatography is to directly prepare the molybdenum target after irradiation into zirconium molybdate acyl gel, load the gel in batches and drip wash the gel, the elution efficiency is low, generally 50-60%, and^99mthe elution peak for Tc is broad. The solvent extraction method comprises extracting and separating Methyl Ethyl Ketone (MEK) in alkaline solution^99mTc, this method has the disadvantages of a lot of organic wastes, complicated equipment, difficult operation, etc. The sublimation method utilizes high temperature to remove molybdenum and technetium oxides^99mTc is separated. Although this method can greatly reduce the product cost, its separation efficiency is low, generally 25% -30%. Also, depending on the difference in the reduction potentials of molybdenum and technetium, the reduction can be separated electrochemically^99mTc. Also, this method is relatively complex to operate, requires high personnel and produces a large amount of radioactive waste. Thus, how to establish a separation from molybdenum^99mThe new process of Tc is of great importance.

Disclosure of Invention

In order to overcome the prior^99mDeficiencies in Tc production process technology, e.g. using reactor production⁹⁹The high-concentration uranium used for Mo has high cost, high risk, low utilization rate, complex separation process and more generated three wastes, and the invention provides a method for enriching by using accelerator irradiation¹⁰⁰Mo production^99mTc.

The invention provides irradiation enrichment by using an accelerator¹⁰⁰Mo production^99mA method of Tc, comprising:

1) preparing a high-power metal molybdenum target;

2) irradiating the high-power metal molybdenum target obtained in the step 1) to obtain^99mTc；

3) Conversion of molybdenum and technetium metals to MoO by high temperature oxidation₃And Tc₂O₇And selectively dissolve Tc₂O₇Filtering the obtained solution to obtain a filtrate which is a technetium solution containing a small amount of molybdenum, and collecting the obtained filter residue;

4) the technetium solution containing a small amount of molybdenum obtained in the step 3) is carried out by utilizing an acidic alumina chromatographic column^99mPurifying Tc;

5) carrying out the filtration residue obtained in the step 3)¹⁰⁰And (4) recovering Mo.

In step 1) of the method, the material for forming the high-power metal molybdenum target is enriched metal molybdenum 100, the chemical purity is more than 99.9 percent,¹⁰⁰the abundance of Mo is more than 80 percent;

the high-power metal molybdenum target is circular or elliptical; the thickness is 200-1000 μm; the elliptical inclined target can increase the beam contact area and improve the yield.

The target chamber is a back plate water-cooling target.

The method for preparing the high-power metal molybdenum target is a high-temperature sintering method;

the density of the high-power metal molybdenum target is 8.5mg/cm³-10mg/cm³(ii) a The thermal conductivity coefficient is 100W/(m DEG C) to 146W/(m DEG C).

Specifically, in the high-temperature sintering method, the temperature is higher than 1200 ℃; specifically 1550 ℃; the time is 1-6 h; in particular for 5 h.

In the irradiation step in the step 2), the irradiation accelerator is a proton accelerator;

the energy of the proton beam is 16MeV-25 MeV; specifically 20.9 Mev;

the flow intensity is 1 muA-2000 muA; specifically 1.0 muA;

the irradiation time is more than 1 hour; in particular 1-10 hours.

In the step 3), the temperature is 750-900 ℃ in the high-temperature oxidation step; in particular 800 ℃;

the oxidant is oxygen with purity more than 99%;

the flow rate of the oxygen gas is 10mL/min-500 mL/min; specifically 40 mL/min;

the oxidation time is 10-60 min; specifically 30 min.

This step can convert the molybdenum and technetium metals to oxides.

In the selective dissolving step of the step 3), the solvent is at least one selected from water, a weakly alkaline solution and normal saline;

the weak alkaline solution is at least one of ammonia water and sodium hydroxide aqueous solution;

the concentration of the weak alkaline solution is less than 0.2 mol/L;

the dissolving temperature is 25-80 ℃; in particular 60 ℃.

The step 4) of purifying comprises the following steps: firstly, adjusting the pH value of the technetium solution containing a small amount of molybdenum to 4-5, and leaching the technetium solution on a chromatographic column;

the regulator used in the step of regulating the pH value is a nitric acid or hydrochloric acid solution; the concentration of the regulator is 0.2-1.0 mol/L;

the chromatographic column is an acidic alumina column;

the length of the chromatographic column is 2cm-5cm, specifically 2.5 cm; the column diameter is 0.5cm-1.5 cm; specifically 1.0 cm;

in the chromatographic column, the pH value of the acidic alumina is 4-5; in particular 4.5; the grain diameter is 100-250 μm;

the eluent is normal saline;

the dosage of the eluting agent is 2-10 column volumes; specifically 6 column volumes;

the leaching speed is 0.5mL/min-2.0 mL/min; specifically 1.0 mL/min.

The step 5) of recovering comprises the following steps:

dissolving the filter residue with ammonia water, evaporating to dryness, and reducing at high temperature to obtain metal¹⁰⁰Mo。

In the dissolving step, the concentration of ammonia water is 1-13 mol/L; in particular 6.5 mol/L;

in the step of drying by distillation, the temperature is 50-90 ℃;

the high-temperature reduction step comprises: under the condition of the existence of carrier gas, firstly carrying out low-temperature conversion and then carrying out high-temperature reduction;

specifically, in the low-temperature conversion step, the temperature is firstly increased to 80-100 ℃, the temperature is kept for 20-40min, and then the temperature is increased to 300-500 ℃;

specifically, the temperature is firstly increased to 90 ℃ and is preserved for 30min, and then the temperature is increased to 400 ℃ and is preserved for 0.5 h;

in the high-temperature reduction step, the temperature is firstly preserved for 50-70min at the temperature of 500-; specifically, the temperature is preserved for 60 minutes at 600 ℃ and then preserved for 3 hours at 1000 ℃;

the carrier gas is hydrogen-argon mixed gas; particularly hydrogen-argon mixed gas with the volume percentage of 2-4% of hydrogen; the volume percentage of the hydrogen is specifically 4%;

the gas flow of the carrier gas is 40-200 mL/min; in particular to 100 mL/min.

The present invention selectively dissolves technetium oxide using water, physiological saline and low concentration ammonia or sodium hydroxide. The main principle is as follows: tc₂O₇Easily soluble in water and weakly alkaline solution, MoO₃The solubility in water and weak alkaline solution is very low, and the water soluble type water. The concentration of ammonia water or sodium hydroxide solution in the process is less than 0.2 mol/L. After selective dissolution will¹⁰⁰MoO₃Filtering the residue to obtain technetium solution containing a small amount of molybdenum, filtering the filtrate, and collecting the residue¹⁰⁰MoO₃And recycling the waste water.

Compared with the prior art, the invention has the following advantages:

firstly, an accelerator is used for irradiating the molybdenum target, so that the construction cost is lower than that of a reactor;

secondly, the molybdenum target does not need to be dissolved and prepared into a generator, thereby avoiding generating a large amount of radioactive waste liquid and realizing^99mSeparation of Tc and¹⁰⁰mo is recycled and reused, greatly reducing^99mThe production cost of Tc.

Thirdly, molybdenum and technetium are converted into corresponding oxides by means of high-temperature oxidation, and then the technetium oxide is selectively dissolved. In the whole separation process, the separation process is carried out,¹⁰⁰the dissolution amount of Mo is very small, which is beneficial to^99mThe further purification of the Tc is carried out,^99mtc separation efficiency can reach more than 95%. In addition, the process is also greatly improved¹⁰⁰The recovery and utilization efficiency of the Mo is improved,¹⁰⁰the Mo recovery rate can reach more than 90 percent.

Drawings

FIG. 1 is a process flow diagram of the present invention.

FIG. 2 shows a molybdenum target before irradiation¹⁰⁰Mo)。

Fig. 3 shows the deposition of molybdenum-technetium oxide on a quartz tube after high temperature conversion.

FIG. 4 shows the separation before and after^99mGamma energy spectrum of Tc.

FIG. 5 shows the Na obtained^99mTcO₄Gamma energy spectrum of (2).

Detailed Description

The present invention will be further illustrated with reference to the following specific examples, but the present invention is not limited to the following examples. The method is a conventional method unless otherwise specified. The starting materials are commercially available from the open literature unless otherwise specified.