CN103337270A - Method for preparing radionuclide 95m, 97mTC - Google Patents

Abstract

The invention discloses a new method for preparing radionuclide ^{95m, 97m} T _C , its main technical feature is that the natural Mo target irradiated by deuterium nuclei (d, ² H) uses commercially available H ₂ O ₂ Dissolve, use NaOH to convert the dissolved Mo and T _C into Na ₂ MoO ₄ and Na ₂ T _{CO 4} , and keep the alkalinity of the solution at about 10%; Na ₂ MoO ₄ solution containing ^{95m, 97m} T _C After being applied to the Dowex-1 anion exchange resin column, rinse with NaOH with a weight concentration of 9.5~10.5% to wash off the Mo in the solution, and then use 1.5~2.5mol/L HCl and 2~3mol/L HNO respectively ₃ Rinse to remove other impurities, and finally use 5.0-8.0 times the volume of the exchange column to rinse with HNO ₃ with a concentration of 7.0-8.0 mol/L. ^{95m, 97m} Tc prepared by the present invention, Mo content spectrophotometric detection is zero, the radioactive nuclear purity of Tc is greater than 99.9%, the radiochemical purity of ^{95m, 97m} Tc is greater than 99.0%, and the preparation method operating procedure is simple, no The use of organic extractants will not cause secondary pollution to the environment.

Description

Method for preparing radionuclide 95m, 97mTC

technical field

The present invention relates to the field of isotope technology, and more specifically relates to a method for preparing radionuclide ^{95m, 97m} Tc by irradiating a natural Mo target with a deuteron (d, ² H).

Background technique

Since there is no stable nuclide in anthurium, it is necessary to use technetium with a moderate half-life in order to study the geochemistry of technetium, the nuclide migration of technetium (as a tracer nuclide of the isotope ⁹⁹ Tc with a long half-life) and the behavior of anthurium in plants and animals. radioactive isotopes. Technetium radioisotopes mainly include ⁹³ Tc (T _1/2 =43.5m), ^95m Tc (T _1/2 =61d), ⁹⁶ Tc (T _1/2 =51.5m), ^97m Tc (T _1/2 =91d ), ^99m Tc (T _1/2 =6.02h), etc. Among them, the half-lives of ⁹³ Tc, ⁹⁶ Tc and ^99m Tc are relatively short, only tens of minutes to several hours, which are not suitable for technetium geochemistry, technetium Nuclide migration research, etc.; ^95m Tc and ^97m Tc have relatively long half-lives, 61d and 91d respectively, which are suitable for technetium geochemistry and technetium nuclide migration research.

^{95m, 97m} Tc is generally produced through accelerators. There are mainly two methods reported in the literature: one method is that a particle ( ⁴ He) bombards the nickel target ⁹³ Nb(a, 2n) ^95m Tc to produce ^95m Tc, which requires Enrichment of ⁹³ Nb requires high cost of target materials, and in the literature, nickel targets are only dissolved with a mixed acid of concentrated hydrochloric acid and concentrated nitric acid, without radiochemical separation of Tc and Nb. Another method is to bombard the Mo target ^nat Mo (p, xn) ^95m Tc with 20-22 MeV protons ( ¹ H ), the radiochemical separation includes the dissolution of the Mo target, the filtration of molybdic acid, the HDEHP extraction of Mo and impurities, and the extraction agent Although this method has carried out radiochemical separation, the separation process is relatively complicated, and the organic extractant HDEHP (di(2-ethylhexyl) phosphoric acid) is used, which is easy to cause secondary pollution to the environment.

The production of ^{95m, 97m} Tc with an accelerator involves the preparation of Mo targets, the irradiation of Mo targets, the dissolution of irradiated Mo targets, and the radiochemical separation of Mo and Tc. Among them, the preparation of Mo target generally adopts electroplating method, vacuum sputtering method, Mo sheet pasting method, and Mo sheet direct processing. The dissolution of irradiated Mo target mainly includes the dissolution method of aqua regia (a mixture of concentrated hydrochloric acid and concentrated nitric acid), concentrated nitric acid or concentrated sulfuric acid, 10% NaOH (or 1mol/L NaOH) and 30% H ₂ O ₂ solution heating and dissolving method, ammonia water and 30% H ₂ O ₂ mixed solution dissolution method, etc. The concentrated acid dissolution method needs to add a large amount of alkali to neutralize the acid, and the operation is more cumbersome; the ammonia water and 30% H ₂ O ₂ mixed solution dissolution method, due to the low alkalinity after dissolution, needs to add alkali to make the solution become strongly alkaline. Operation is also more loaded down with trivial details. 10% NaOH (or 1mol/L NaOH) and 30% H ₂ O ₂ solution heating dissolution method, the dissolution process not only needs heating, but the dissolution speed is not fast enough, and the effect is not good. There are many radiochemical separation methods for Mo, including Al ₂ O ₃ chromatographic separation, anion exchange resin exchange, cation exchange resin exchange, Fe(OH) ₃ co-precipitation, solvent extraction or a combination of several methods. It is very difficult to separate trace (~μg level) ^95m,97m Tc from a few grams of Mo by conventional methods, and the separation and purification requirements cannot be met. Co-precipitation and solvent extraction are cumbersome to operate, the recovery rate of Tc is not high, and it is easy to cause secondary pollution; the operation of Al ₂ O ₃ chromatographic separation is also cumbersome, the treatment of Al ₂ O ₃ is also difficult, and it is easy to cause the leakage of Mo. wear etc. The literature reports the production of ^95m Tc by ^nat Mo (p, xn) ^95m Tc reaction, and the radiochemical separation of Mo and ^95m Tc only lists the approximate steps, including the dissolution of Mo, filtration of molybdic acid, HDEHP extraction of Mo and impurities, and The removal of the extractant, etc., did not detail the specific steps; in addition, although this method has carried out radiochemical separation, the separation process is relatively complicated, and the organic extractant HDEHP (di(2-ethylhexyl) phosphoric acid) is used, which is easy to damage the environment. cause secondary pollution. Another literature reported that ⁹³ Nb(a, 2n) ^95m Tc was bombarded with a particle ( ⁴ He) to produce ^95m Tc. This method needs to enrich ⁹³ Nb, and the cost of the target material is high. In the literature, only the nickel target Dissolution was carried out with a mixed acid of concentrated hydrochloric acid and concentrated nitric acid, and no radiochemical separation of Tc and Nb was performed.

Contents of the invention

For the present situation of producing radionuclide ^{95m, 97m} Tc in the prior art, the purpose of the present invention is to provide a kind of deuteron (d, ² H) irradiation bombardment natural Mo target to produce the radionuclide purity of Tc greater than 99.9%, And the new method of ^{95m, 97m Tc whose radiochemical purity of 95m, 97m} Tc is greater than 99.0%, at the same time overcome the problems of high preparation cost, complicated separation operation of Mo and Tc, easy to cause secondary pollution to the environment by using organic extractant, etc. .

For the purpose of the present invention, the basic method of the present invention is to use NaOH of sufficient amount earlier after the Mo leaching is got off, then use HCl, HNO again with HCl, _HNO The trace Mo and the Mg, Mn, Cr, Mg, Mn, Cr, Fe, Si and other non-radioactive substances and a small amount of ⁹⁵ Zr, ^95,96 Nb, ^94,95,97,103 Ru and other radioactive impurities are washed down, while the required ^{95m, 97m} Tc remains on the Dowex-1 anion exchange resin, Finally, the Na ₂ ^{95m, 97m} TcO ₄ is rinsed with HNO ₃ with a weight concentration of about 7.5mol/L, so as to ensure that the high-concentration HNO ₃ eluent does not contain other metal ions and radioactive impurities, and the content of Mo is detected by spectrophotometry. The radionuclear purity of Tc is greater than 99.9%, and the radiochemical purity of ^{95m, 97m} Tc is greater than 99.0% of high-purity ^{95m, 97m} Tc.

The method for producing radionuclide ^95m,97m Tc provided by the invention mainly comprises the following steps:

(1) Preparation of natural Mo target: use natural Mo plate to process Mo target sheet according to the size of accelerator target holder;

(2) Mo target irradiation: irradiate and bombard the Mo target with a deuteron (d, ² H) beam with an intensity of 150-155 μA for 28-33 hours, and leave it for no less than 43 days after irradiation to enter the dissolution process;

(3) Dissolution of irradiated Mo target: Dissolve the irradiated Mo target with commercially available H ₂ O ₂ , the amount of H ₂ O ₂ is calculated as 2.5~5.0mL/g Mo, and add NaOH with a weight concentration of 9.5~10.5% after fully dissolving , convert the dissolved Mo and T _C into Na ₂ MoO ₄ and Na ₂ T _{CO 4} , the amount of NaOH is calculated according to 5.0~8.0mL/g Mo, and the alkalinity of the solution is maintained at 9.5~10.5%;

(4) Separation of Mo from ^{95m, 97m} Tc: put the Na ₂ MoO ₄ solution containing ^{95m, 97m} T _C on the Dowex-1 anion exchange resin column, rinse with NaOH with a weight concentration of 9.5~10.5% to Mo in the eluent Content spectrophotometry is zero, rinse with distilled water to remove NaOH; then rinse with HCl with a volume of 10.0 to 12.5 times the volume of the exchange column and a concentration of 1.5 to 2.5 mol/L. ~3mol/L HNO ₃ eluting to remove trace Mo, Mg, Mn, Cr, Fe, Si non-radiative substances and a small amount of ⁹⁵ Zr, ^95,96 Nb, ^94,95,97,103 Ru radioactive impurities; finally use the exchange column Wash with 5.0-8.0 times the volume of HNO ₃ with a concentration of 7.0-8.0mol/L to obtain a Na ₂ TcO ₄ solution containing ^{95m, 97m} Tc;

(5) Conversion treatment: heating and evaporating the solution obtained in step (4) to remove HNO ₃ , and then using HCl to remove the residual HNO ₃ , and finally obtain the radiochemical purity of Tc with radionuclear purity greater than 99.9%, ^{95m, 97m} Tc Greater than 99.0% Na ₂ ^{95m, 97m} TcO ₄ solution.

The present invention adopts natural Mo target to prepare ^{95m, 97m} Tc. Natural Mo targets mainly contain ⁹² Mo (14.84%), ⁹⁴ Mo (9.25%), ⁹⁵ Mo (15.92%), ⁹⁶ Mo (16.68%), ⁹⁷ Mo (9.55%), ⁹⁸ Mo (24.13%) and ¹⁰⁰ Mo ( 9.63%) and other isotopes, and also contains trace elements such as Mg, Mn, Cr, Fe, Si, etc., and the natural Mo targets are irradiated with deuterons (d, ² H), mainly (d, 2n), (d, n) etc. Nuclear reactions, the main isotopes of Tc are:

⁹³ Tc: ⁹² Mo (d, n) ⁹³ Tc, T _1/2 = 43.5m;

^95m Tc: ⁹⁴ Mo (d, n) ^95m Tc, T _1/2 =61d;

⁹⁵ Mo (d, 2n) ^95m Tc, T _1/2 = 61d;

⁹⁶ Tc: ⁹⁵ Mo (d, n) ⁹⁶ Tc, T _1/2 = 4.28d;

^97m Tc: ⁹⁶ Mo (d, n) ^97m Tc, T _1/2 =91.4d;

⁹⁷ Mo (d, 2n) ^97m Tc, T _1/2 = 91.4d

The half-life of ⁹³ Tc is 43.5m, and it decays after 1 day of irradiation, so its influence can be ignored; the half-life of ⁹⁶ Tc is 4.28d, and its influence can be ignored after 43 days of irradiation (generally 10 radionuclides are placed considered stable after half-life). Use deuteron (d, ² H) to irradiate the natural Mo target. After the irradiated Mo target is placed for 43 days, the isotope of Tc only needs to focus on the target products ^95m Tc and ^97m Tc. The next problem is to solve the relationship between Mo and ^{95m, 97m} Radiochemical separation of Tc.

How to remove a large amount of Mo (gram level) and a small amount of non-radiative substances such as Mg, Mn, Cr, Fe, Si and trace amounts of ⁹⁵ Zr, ^95,96 Nb, ^94,95,97,103 through radiochemical separation of irradiated natural Mo targets Ru and other radioactive impurities, to obtain 95m, 97m Tc with a radionuclear purity of Tc greater than 99.9% and a radiochemical purity of ^{95m , 97m} Tc greater than 99.0%, are technical difficulties in the preparation of ^{95m, 97m} Tc using natural Mo targets. The above technical solution of the present invention solves this technical problem well, and the preparation method has simple operation procedures, does not use an organic extractant, and will not cause secondary pollution to the environment.

In the above-mentioned scheme for producing radionuclide ^{95m, 97m} T _C , the Dowex-1 anion exchange resin is preferably Dowex-1 anion exchange resin that has undergone inversion treatment. The transformation Dowex-1 anion exchange resin means that after the Dowex-1 anion exchange resin is put on the column, it is rinsed with distilled water, HCl, distilled water, HNO ₃ , and distilled water successively, and then rinsed with NaOH with a weight concentration of 9.5 to 10.5%. , Dowex-1 anion exchange resin with resin alkalinity maintained at 9.5~10.5% after repeated washing treatment. During the transformation process of Dowex-1 anion exchange resin, it is best to use HCl, distilled water, HNO ₃ , and distilled water to perform circular leaching in sequence, and the number of cycles is not less than 3 times until the eluent is neutral. In the process of cyclic rinsing, the rinsing flow rate of each link is preferably controlled in the range of 0.4-0.6 mL/min. Dowex-1 resin should be cleaned, dried, ground and sieved before being applied to the anion exchange column, and Dowex-1 resin with a particle size of 80-120 mesh should be selected.

In the above scheme for preparing radionuclide ^{95m, 97m} T _C , use commercially available H ₂ O ₂ to dissolve and irradiate the Mo target, preferably using a small amount of multiple dissolution methods, at least use commercially available H _{2 O} Mo target 2 times, the amount of H ₂ O ₂ should be dissolved in the range of 0.5~1.0mL/g Mo each time, the total dosage is 2.5~5.0mL/g Mo; use after irradiation Mo target solution on Dowex-1 anion exchange resin column NaOH with a weight concentration of 9.5-10.5% is used for leaching, and the leaching flow rate should be controlled in the range of 0.4-0.6 mL/min.

In order to prepare high-purity ^{95m, 97m} Tc, the inventors improved the Mo dissolution method. The preparation of high-purity ^{95m, 97m} Tc involves the preparation of Mo targets, the irradiation of Mo targets, the dissolution of irradiated Mo targets, and the radiochemical separation of irradiated Mo targets. In the preparation of Mo target, considering factors such as difficulty and cost, the advantages and disadvantages of several methods were compared. In the present invention, high-purity Mo plate (99.99%) is used to directly process and irradiate Mo target. Dissolution of the irradiated Mo target, the inventors found during the experiment that the dissolution of Mo with commercially available H ₂ O ₂ (weight concentration about 30% H ₂ O ₂ ) alone was better than that with 10% NaOH (or 1mol/L NaOH) and The commercially available H ₂ O ₂ mixed solution has fast dissolution rate, good effect, and does not need to be heated. Therefore, the present invention uses commercially available H ₂ O ₂ to dissolve Mo first, and then dissolves the dissolved Mo with NaOH with a weight concentration of about 10%. , Tc is converted into the Na ₂ MoO ₄ and Na ₂ TcO ₄ forms required for separation. The radiochemical separation of irradiated Mo targets is the most important link in the preparation process of high-purity ^{95m, 97m} Tc. According to the actual situation of analysis and simulation experiments, the inventor only used Dowex -1 anion exchange resin, and only use NaOH, HCl, HNO ₃ and other inorganic reagents to rinse during the separation process. No organic extractant is used, which will not cause secondary pollution to the environment. After separation and purification, the required microgram level The ^{95m, 97m} Tc, whose Mo content is detected by spectrophotometry is zero, the radionuclear purity of Tc is greater than 99.9%, and the radiochemical purity of ^{95m, 97m} Tc is greater than 99.0%.

Description of drawings

Accompanying drawing 1 is the sample gamma energy spectrogram that the abscissa is channel number.

Accompanying drawing 2 is sample gamma energy spectrogram.

It can be seen from the gamma energy spectra of accompanying drawings 1 and 2 that there is only the characteristic energy spectrum of Tc in the energy spectrum region, and there are no energy spectra of other nuclides, and the purity of radionuclides is greater than 99.9%. Among them, 204keV, 582 keV, 616 keV, 765 keV, 786 keV, 820 keV, 835 keV, 947 keV, 1039 keV, 1073 keV belong to ^95m Tc; 96.5 keV belongs to ^97m Tc; 252 keV belongs to ¹⁰⁵ Tc; A high-purity Na ₂ TcO ₄ solution containing ^{95m, 97m} Tc was obtained.

Detailed ways:

1. Preparation of natural Mo targets

The purchased high-purity natural Mo plate (99.99%) is processed into a target piece that meets the size requirements according to the requirements of the accelerator target holder. A total of 4 natural Mo targets were processed, one was used for simulation test, one was used for ⁹⁹ Tc ^m recovery test, and the other two were used for irradiation target.

2. Irradiation of Mo target

The natural Mo target was bombarded with d nuclei ( ² H ) radiation, and after 45 days of "cooling" (that is, placed for 45 days to allow short half-life isotopes such as ⁹³ Tc and ⁹⁶ Tc to decay), the radiochemical separation of the irradiated target was carried out.

The irradiation conditions of the two Mo targets are shown in Table 1.

Table 1 Irradiation of Mo target

3. Separation of simulated Mo target

Because the irradiated Mo target contains strong radioactivity, it is not suitable to directly carry out experiments such as dissolution and separation of the irradiated Mo target. Therefore, before the separation of the irradiated Mo target, a "cold test" must be carried out, that is, the dissolution of the simulated Mo target should be carried out first. , simulated Mo target separation and ⁹⁹ Tc ^m recovery experiments, etc., in order to find out the methods and conditions for experiments such as dissolution and separation of irradiated Mo targets.

1) Simulate the dissolution of Mo target The dissolution of Mo adopts an improved dissolution method, that is, directly dissolves Mo with 30% H ₂ O ₂ , and does not need to be heated during the dissolution process.

(1) Dissolution of Mo flakes

Cut 3g Mo sheet with a weight of 1-5mm thickness into small pieces (3mm×3mm), and add 30% H ₂ O ₂ to dissolve the Mo sheet in 5 times at 0.5mL/gMo each time. The dissolution process does not require heating . After dissolving, add NaOH with a weight concentration _of 10% to convert the dissolved MoO ₃ into Na ₂ MoO ₄ . The amount of NaOH used is calculated as 8.0mL/g Mo. ₄ The alkalinity of the solution is maintained at about 10%.

(2) Simulate the dissolution of Mo target

Fix the simulated Mo target in the dissolution tank, and use the method (1) above to dissolve the simulated Mo target by adding 30% H ₂ O ₂ at a weight concentration of 5 times at 0.5mL/g Mo each time. Then add NaOH with a weight concentration of 10% to convert the dissolved MoO ₃ into Na ₂ MoO ₄ . The amount of NaOH used is calculated as 8.0mL/g Mo, the alkalinity of the Na ₂ MoO ₄ solution is maintained at about 10%, and the dissolved amount of Mo is controlled. Around 6g.

2) Mo separation

As mentioned above, Dowex-1 anion exchange resin (100±20 mesh, ф1.0×20.0cm) was used to separate Tc from Mo, etc.

(1) Treatment of Dowex-1 resin

Wash the Dowex-1 resin, dry it, grind it with a grinder, and then sieve it with a molecular sieve, and take 100±20 mesh Dowex-1 resin for use.

Put the above-mentioned 100±20 mesh Dowex-1 resin on an anion exchange column. First wash with distilled water, then rinse 100-150mL with 6mol/L HCl, wash away HCl with distilled water until neutral, then rinse 100-150mL with 3mol/L HNO ₃ , and wash away HNO ₃ with distilled water until neutral. Repeat the above steps 3 times, and control the flow rate at about 0.5 mL/min.

(2) Transformation of Dowex-1 resin

Rinse the above-mentioned treated Dowex-1 resin with 10% NaOH, and the rinse volume is about 500 mL, so that the alkalinity of Dowex-1 resin is maintained at about 10%.

(3) Separation of Mo

Put the Na ₂ MoO ₄ solution containing 5.9532g Mo (with a basicity of about 10%) on the transformed Dowex-1 anion exchange resin column, and then wash it with 10% NaOH, and the flow rate is controlled at about 0.5mL/min. Its washing volume and content are shown in Table 2. The Mo content was measured spectrophotometrically.

Spectrophotometric measurement of Mo: take the sample in a 50 mL volumetric flask, dilute with water to 25 mL, add 2.5 mL of HNO ₃ (before use of HNO ₃ , add 0.5% KMnO ₄ solution dropwise to a stable light red); then add 5 mL of 25% KSCN solution and 2.5mL 10% SnCl ₂ solution, shake well, dilute to 50mL with water, let stand for 15min, measure absorbance at 430nm with 1cm cuvette.

Table 2 10% NaOH elution volume and Mo content

The cumulative total Mo content in the above table is 5.8031g, and the recovery rate is 97.5%. In order to ensure that the Dowex-1 anion exchange resin does not contain Mo as much as possible, after rinsing 1000 mL, the absorbance was 0, and then leaching 200mL of 10% NaOH solution.

After rinsing with 10% NaOH, wash away the NaOH with distilled water to make the Dowex-1 anion exchange resin neutral, and the absorbance of the eluent is 0; then rinse 120-150mL with 2mol/L HCl, and the eluent The absorbance is 0; then rinse 100-120mL with 3mol/L HNO ₃ , and the absorbance of the eluent is also 0; finally, wash off the HNO ₃ with distilled water until the eluent is neutral, and the absorbance of the eluent is 0 . The absorbance of HCl eluent, _HNO3 eluent and distilled water eluent are all 0, indicating that their eluents do not contain Mo. In addition, the ICP (inductively coupled plasma) analysis (detection limit ppm level) of the HNO ₃ eluent after treatment was consistent with the blank sample (<0.1 ppm), which indicated that the HNO ₃ eluent did not contain Mo or Mo content is very small.

The above experimental results show that Na ₂ MoO ₄ can be completely washed off by 10% NaOH solution, so as to ensure that there is no Na ₂ MoO ₄ in ^{the 95m, 97m} Tc sample washed thereafter; by 2mol/L HCl and 3mol /L of HNO ₃ rinsing further ensures that Mo and other impurities are not contained in the Tc sample leached thereafter.

3) ⁹⁹ Tc ^m recovery test

The recovery test of ⁹⁹ Tc ^m is exactly the same as the separation test of Mo in the simulated Mo target, the only difference is that 7.5mCi of Na ₂ ⁹⁹ Tc ^m O ₄ solution is added before the Na ₂ MoO ₄ solution is applied to the anion exchange column and then applied to the column.

During the separation process of the simulated Mo target, no radioactivity was detected in the eluent after elution with 10% NaOH, 2mol/L HCl and 3mol/L HNO ₃ , which indicates that:

(1) 10% NaOH cannot wash down Na ₂ ⁹⁹ Tc ^m O ₄ ;

(2) 2mol/L HCl cannot wash down Na ₂ ⁹⁹ Tc ^m O ₄ ;

(3) 3mol/L HNO ₃ also cannot wash down Na ₂ ⁹⁹ Tc ^m O ₄ .

In particular, 3mol/L HNO ₃ can generally elute most metal _ions from the anion exchange column. HNO ₃ (7.5mol/L) eluting Na ₂ ⁹⁹ Tc ^m O ₄ , so as to ensure that the high-concentration HNO ₃ eluent does not contain other metal ions and obtain high-purity Tc.

After washing with 3mol/L HNO ₃ , use 7.5mol/L HNO ₃ to rinse 60-100mL until Na ₂ ⁹⁹ Tc ^m O ₄ is completely washed down. At the same time, using 7.5mCi Na ₂ ⁹⁹ Tc ^m O ₄ as a reference, the recovery rate of ⁹⁹ Tc ^m was calculated, and the recovery rate was >99%. The content was consistent with the blank sample (<0.1ppm) by ICP detection, indicating that 7.5mol /L of HNO ₃ eluent does not contain Mo or contains very little Mo, thus ensuring high-purity Tc.

4. Separation of irradiated Mo targets

The dissolution and separation of the irradiated Mo target is exactly the same as that of the simulated Mo target.

1) Dissolution of irradiated Mo target

Target No. 1 weighed 120.5g before dissolving, weighed 117.4g after dissolving, and the dissolved amount was 3.1 g; No. 2 target weighed 122.4g before dissolving, weighed 119.4g after dissolving, and dissolved amount was 3.0 g. The combined solution contained 6.1 g Mo , the volume is about 40mL, and the alkalinity of the solution is controlled at about 10%.

2) Separation of irradiated Mo targets

Put the above-mentioned combined solution on the converted Dowex-1 anion exchange resin column, then rinse with 10% NaOH, the flow rate is controlled at about 0.5 mL/min, and the volume of NaOH rinse is 1200 mL; then rinse with about 100 mL of distilled water then rinse with 150 mL of 2mol/L HCl; then rinse with 120 mL of 3mol/L _HNO3 ; finally rinse _100mL with 7.5mol/L of HNO3 to obtain _Na2 containing ^{95m, 97m} Tc _TcO4 solution.

After the Na ₂ TcO ₄ solution containing ^{95m, 97m} Tc was evaporated to remove HNO ₃ , then 2~3 drops of HCl was added to remove the residual HNO ₃ , and finally 2 mL of distilled water was added to dissolve to obtain a Na ₂ TcO ₄ solution containing ^{95m, 97m} Tc. Take a small amount of solution and use paper chromatography (developing solvent: acetonitrile: water = 8:2) to measure the radiochemical purity of ^{95m, 97m} Tc, and the radiochemical purity is 99.0%. In addition, take a small amount of solution to make the source, and measure the gamma energy spectrum; the gamma energy spectrum is shown in Figure 1 and Figure 2. It can be seen from the figure that there is only the characteristic energy spectrum of Tc in the energy spectrum area, and there is no energy spectrum of other nuclides, and the purity of radionuclides is greater than 99.9%. Among them, 204keV, 582keV, 616keV, 765keV, 786keV, 820keV, 835keV, 947keV, 1039keV, 1073keV belong to ^95m Tc; 96.5keV belongs to ^97mTc ; 252keV belongs to ^105Tc ; Pure Na ₂ TcO ₄ solution containing ^{95m, 97m} Tc.

Claims (8)

1. A method for producing radionuclide ^{95m, 97m} T _C is characterized in that it mainly comprises the following process steps: (1) Preparation of natural Mo target: use natural Mo plate to process Mo target sheet according to the size of accelerator target holder; (2) Mo target irradiation: irradiate and bombard the Mo target with a deuteron (d, ² H) beam with an intensity of 150-155 μA for 28-33 hours, and leave it for no less than 43 days after irradiation to enter the dissolution process; (3) Dissolution of irradiated Mo target: Dissolve the irradiated Mo target with commercially available H ₂ O ₂ , the amount of H ₂ O ₂ is calculated as 2.5~5.0mL/g Mo, and add NaOH with a weight concentration of 9.5~10.5% after fully dissolving , convert the dissolved Mo and T _C into Na ₂ MoO ₄ and Na ₂ T _{CO 4} , the amount of NaOH is calculated according to 5.0~8.0mL/g Mo, and the alkalinity of the solution is maintained at 9.5~10.5%; (4) Separation of Mo from ^{95m, 97m} Tc: put the Na ₂ MoO ₄ solution containing ^{95m, 97m} T _C on the Dowex-1 anion exchange resin column, rinse with NaOH with a weight concentration of 9.5~10.5% to Mo in the eluent Content spectrophotometry is zero, rinse with distilled water to remove NaOH; then rinse with HCl with a volume of 10.0 to 12.5 times the volume of the exchange column and a concentration of 1.5 to 2.5 mol/L. ~3mol/L HNO ₃ eluting to remove trace Mo, Mg, Mn, Cr, Fe, Si non-radiative substances and a small amount of ⁹⁵ Zr, ^95,96 Nb, ^94,95,97,103 Ru radioactive impurities; finally use the exchange column Wash with 5.0-8.0 times the volume of HNO ₃ with a concentration of 7.0-8.0mol/L to obtain a Na ₂ TcO ₄ solution containing ^{95m, 97m} Tc; (5) Conversion treatment: heating and evaporating the solution obtained in step (4) to remove HNO ₃ , and then using HCl to remove the residual HNO ₃ , and finally obtain the radiochemical purity of Tc with radionuclear purity greater than 99.9%, ^{95m, 97m} Tc Greater than 99.0% Na ₂ ^{95m, 97m} TcO ₄ solution. 2. the method for producing radionuclide ^{95m according to claim 1, the method for 97m} _TC is characterized in that said Dowex-1 anion exchange resin post is the Dowex-1 anion exchange resin post after conversion treatment, said Transformation treatment is to wash with distilled water, HCl, distilled water, HNO ₃ , distilled water successively after the anion exchange column on Dowex-1 resin, and then rinse with NaOH with a weight concentration of 9.5~10.5%, so that the alkalinity of the resin is maintained at 9.5~10.5%. 3. the method for producing radionuclide ^{95m according to claim 2, the method for 97m} T _C is characterized in that Dowex-1 resin is Dowex-1 through cleaning, drying, grinding and sieving treatment particle diameter at 80 ~ 120 purpose. 1 resin. 4. the method for producing radionuclide ^{95m according to claim 2, the method for 97m} T _C is characterized in that after the anion exchange column on the Dowex-1 resin, use HCl, distilled water, HNO ₃ , distilled water circulation rinse successively, circulate The number of times is not less than 3 times, and the distilled water in the cyclic rinsing is rinsed until the eluent is neutral. 5. the method for producing radionuclide ^{95m according to claim 4, the method for 97m} T _C is characterized in that using HCl, distilled water, HNO ₃ , distilled water to carry out circulation leaching successively, and leaching flow velocity is controlled at 0.4～0.6mL/ min. 6. The method for producing radionuclide ^{95m, 97m} T _C according to any one of claims 1 to 5, characterized in that the irradiated Mo target is dissolved at least twice with commercially available H ₂ O ₂ , and each H ₂ O ₂ The dosage is 0.5~1.0mL/g Mo each time, and the total dosage is 2.5~5.0mL/g Mo. 7. according to the method for producing radionuclide ^{95m described in one of claims 1 to 5, 97m} T _C , it is characterized in that Dowex-1 anion exchange resin post with weight concentration 9.5～10.5% on the irradiation Mo target solution NaOH rinsing, the rinsing flow rate is controlled at 0.4-0.6 mL/min. 8. the method for producing radionuclide ^{95m according to claim 6, the method for 97m} T _C is characterized in that Dowex-1 anion exchange resin column is washed with the NaOH of weight concentration 9.5～10.5% on the irradiation Mo target solution, The elution flow rate was controlled at 0.4-0.6 mL/min.

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