In-target produced [11C]methane: Increased specific radioactivity

The N-14(rho, alpha)C-11 reaction on N-2-O-2 or N-2-H-2 gaseous systems as targets in proton bombardment allows for the production of [C-11]CO2 and [C-11]CH4. We report the target production of [C-11]CH4 and the gas phase iodination to produce [C-11]CH3I with high specific radioactivity (SA). SA was calculated for four different radiopharmaceuticals produced in-house from both target produced [C-11]CO2 and [C-11]CH4. For [C-11]raclopride we obtained an average SA of 3908 GBq/mu mol (106000 Ci/mmol) at the end of bombardment for the last 52 productions, which is a 32-fold increase compared to when using the in-house [C-11]CO2 target. (C) 2008 Elsevier Ltd. All rights reserved.