Methods have been developed for the labelling of acetate and palmitic acid with the positron-emitting radionuclide,11C (T=20.4 min). Labelling was achieved via carbonation of the appropriate alkyl magnesium bromide (methyl magnesium bromide
or n-pentadecyl magnesium bromide) with11C-labelled carbon dioxide produced by the14N(p, α)11C nuclear reaction. The radiochemical yield and speed of each method of labelling are such that a radiochemically pure product
is obtained in injectable form and in activity (>10 mCi) suitable for the study of myocardial metabolism by emission-computerised
axial tomography. High pressure liquid chromatography and thin layer chromatography were used to assess the radiochemical
purity of each radiopharmaceutical. The specific activity of11C-labelled acetate was estimated by an enzymic procedure to be greater than 0.5 Ci/μmole.