Method for producing radioactive labeled substance, device for producing radioactive labeled substance, and method for evaporatively concentrating radioactive metal nuclide

A method for producing a radioactive labeled substance formed by labeling a compound with a radioactive metal nuclide, comprising:

• an adsorption process in which a radioactive dissolving liquid formed by dissolving a radioactive metal nuclide in an acidic dissolving liquid is passed through an ion-exchange resin to cause the radioactive metal nuclide to be adsorbed onto the ion-exchange resin;
• an elution process in which an acidic eluent is passed through the ion-exchange resin and ultimately collected as a radioactive solution resulting from an ion exchange between the radioactive metal nuclide adsorbed on the ion-exchange resin and the eluent;
• a first evaporative concentration process in which a radioactive solution collected in the elution process is heated to evaporate a solvent in the radioactive solution so as to obtain a concentrated liquid containing the radioactive metal nuclide;
• a second evaporative concentration process in which a low-boiling organic solvent having a lower boiling point than water is added to the concentrated liquid, and the concentrated liquid is heated to induce azeotropic boiling of the concentrated liquid and the low-boiling organic solvent so as to obtain an evaporative concentrate of the radioactive metal nuclide,
• wherein, in the second evaporative concentration process, the azeotropic boiling of the concentrated liquid and the low-boiling organic solvent is induced so that a pH of the evaporative concentrate of the radioactive metal nuclide is substantially neutral;
• and
• a labeling process in which the radioactive metal nuclide contained in the evaporative concentrate is caused to react with a label-target compound so as to obtain a radioactive labeled substance.

A device comprising an evaporative concentration section, the evaporative concentration section including:

• a concentration container;
• a heater configured to heat the concentration container;
• an organic solvent tank for holding a low-boiling organic solvent having a lower boiling point than water;
• an introducing section configured to introduce the low-boiling organic solvent held in the organic solvent tank through an introduction passage into the concentration container;
• a temperature sensor configured to detect a temperature of the concentration container;
• and
• a controller,
• wherein the controller is configured to sequentially perform:
• a first evaporative concentration process in which, when a radioactive solution formed by dissolving a radioactive metal nuclide in an acidic aqueous solution is held in the concentration container, the controller drives the heater to heat the concentration container thereby evaporating a solvent contained in the radioactive solution so as to obtain a concentrated liquid containing the radioactive metal nuclide, and
• a second evaporative concentration process in which, after causing the introducing section to introduce the low-boiling organic solvent in the organic solvent tank into the concentration container, the controller drives the heater to heat the concentration container thereby inducing azeotropic boiling of the concentrated liquid and the low-boiling organic solvent so as to obtain an evaporative concentrate of the radioactive metal nuclide,
• wherein, in the second evaporative concentration process, the azeotropic boiling of the concentrated liquid and the low-boiling organic solvent is induced so that a pH of the evaporative concentrate of the radioactive metal nuclide is substantially neutral.