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

The 14N(ρ, α)11C reaction on N2–O2 or N2–H2 gaseous systems as targets in proton bombardment allows for the production of [11C]CO2 and [11C]CH4. We report the target production of [11C]CH4 and the gas phase iodination to produce [11C]CH3I with high specific radioactivity (SA). SA was calculated for four different radiopharmaceuticals produced in-house from both target produced [11C]CO2 and [11C]CH4. For [11C]raclopride we obtained an average SA of 3908 GBq/μmol (106 000 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 [11C]CO2 target.