Production of C-11-labelled n-hexane for use in positron emission imaging

Supported ruthenium catalysts have been used for the production of C-11-labelled n-hexane via a surface reaction carried out at two different temperatures, The process involves high temperature adsorption of (CO)-C-11, resulting in the production of reactive C-11(1) surface species; this is followed by rapid cooling to a much lower temperature at which 1-pentene is adsorbed. The resultant surface species are then hydrogenated at the same temperature producing C-11-labelled hydrocarbons, including n-hexane, which are concentrated and separated by on-line gas chromatography. By injecting the C-11-labelled n-hexane into a catalytic reactor working under steady state conditions it is possible to use positron emission imaging to study reactions inside a working reactor.