Highly Efficient Separation of Ultratrace Radioactive Copper Using a Flow Electrolysis Cell

[Image: see text] Preparing compounds containing the radioisotope (64)Cu for use in positron emission tomography cancer diagnostics is an ongoing area of research. In this study, a highly efficient separation method to recover (64)Cu generated by irradiating the target (64)Ni with a proton beam was developed by employing a flow electrolysis cell (FE). This system consists of (1) applying a reduction potential for the selective adsorption of (64)Cu from the target solution when dissolved in HCl and (2) recovering the (64)Cu deposited onto the carbon working electrode by desorbing it from the FE during elution with 10 mmol/L HNO(3), which applies an oxidation potential. The (64)Cu was selectively eluted at approximately 30 min under a flow rate of 0.5 mL/min from the injection to recovery. The newly developed flow electrolysis system can separate the femtomolar level of ultratrace radioisotopes from the larger amount of target metals as an alternative to conventional column chromatography.