Preparation of [11C]formaldehyde using a silver-containing ceramic catalyst

A ceramic material, prepared from kaolin doped with silver ions in various concentrations, was evaluated as a catalyst. for the conversion of [C-11] methanol into [C-11]formaldehyde in a gas flow system. Employment of [C-11] methanol with a minimized water content, 300 mg of catalyst (20% of silver) at 500degreesC and a *carrier gas flow rate of 40 mL/min resulted in a radiochemical decay-corrected [C-11]formaldehyde yield of 67% relative to [C-11]methanoi. Wet [C-11]methanol under the same conditions gave 54% of [C-11] formaldehyde. Copyright (C) 2003 John Wiley Sons, Ltd.