Abstract Preparation of deuterium-labelled perhexiline from an unsaturated analogue was performed via reduction with deuterium gas and PtO 2 in acetic acid. Low incorporation was observed when using acetic acid as solvent (most abundant mass peak was M math image), but when changing the solvent to deuterium-labelled acetic acid, eg acetic acid-OD or acetic acid-d 4, a higher incorporation was observed (most abundant mass peak was M math ...