Provided is a novel method for labeling a radionuclide such as .sup.211At with a high radiochemical yield under more convenient and stable conditions.

A production method of an aryl compound labeled with a radionuclide includes a step of applying a voltage to a solution A containing a radionuclide and electrolytically oxidizing the radionuclide; and a step of mixing the solution A and a solution B containing a compound S having a halogenated aryl group to substitute a halogen atom on the aryl group of the compound S with the radionuclide.

The invention relates to a method for producing an alkali metal alcoholate solution L.sub.1 in an electrolysis cell E which comprises at least one cathode chamber K.sub.K, at least one anode chamber K.sub.A, and at least one central chamber K.sub.M lying therebetween. The interior I.sub.KK of the cathode chamber K.sub.K is separated from the interior I.sub.KM of the central chamber K.sub.M by a separating wall W comprising at least one alkali-cation-conductive solid ceramic electrolyte (=AFK) F (e.g. NaSICON). During the electrolysis process for producing the alkali metal alcoholates with F instead of F, an improved conductivity is provided, whereby for a constant current density, a lower voltage can be used.

The invention relates to a method for producing an alkali metal alcoholate solution L.sub.1 in an electrolysis cell E which comprises at least one cathode chamber K.sub.K, at least one anode chamber K.sub.A, and at least one central chamber K.sub.M lying therebetween. The interior I.sub.KK of the cathode chamber K.sub.K is separated from the interior I.sub.KM of the central chamber K.sub.M by a separating wall W comprising at least one alkali-cation-conductive solid ceramic electrolyte (=AFK) F (e.g. NaSICON). During the electrolysis process for producing the alkali metal alcoholates with F instead of F, an improved conductivity is provided, whereby for a constant current density, a lower voltage can be used.

The invention relates to a method for producing an alkali metal alcoholate solution L1 in an electrolysis cell E which comprises at least one cathode chamber KK, at least one anode chamber KA, and at least one central chamber KM lying therebetween. The interior IKK of the cathode chamber KK is separated from the interior IKM of the central chamber KM by a separating wall W comprising at least one alkali-cation-conductive solid ceramic electrolyte (=AFK) F (e.g. NaSICON). F has the surface OF.