Recovery of [18F]fluoride from [18O]water in an electrochemical cell

The recovery of [18F]fluoride from [18O]water using an electric field to deposit and remove the fluoride is described. An electrolytic cell was constructed to study [18F]fluoride recovery as a function of voltage, voltage gradient, and time using vitreous carbon and platinum electrodes. The fluoride ion is both deposited onto and removed from the carbon electrode most efficiently at voltages more than 10 V. Typically 95% of the 18F activity from the target could be deposited onto the carbon electrode. Seventy percent of the activity deposited could then be released from the carbon electrode after excitation of the cell with an electric field of an opposite polarity and equal magnitude to the deposition field. These efficiencies were obtained after excitation of the cell for 5 min for both the deposition and the release of [18F]fluoride. The reactivity of [18F]fluoride reclaimed from the electrolytic cell was probed using the syntheses of 2-deoxy-2-[18F]fluoro-D-glucose and para [18F]fluoronitrobenzene as test systems.