A simple Tracerlab module modification for automated on-column [11C]methylation and [11C]carboxylation. 
A modification of commercial [11C]methylation module which can be implemented for both on-column [11C]methylation and [11C]carboxylation in the same automated system is described.  This module configuration was applied to the solid-phase synthesis of N-[11C]methyl-choline ([11C]choline) and L-(S-methyl-[11C])methionine ([11C]methionine), using [11C]CH(3)I as methylating agent, as well as to the synthesis of [11C]acetate by [11C]carboxylation with [11C]CO2 of methylmagnesium chloride with high and reproducible radiochemical yields in short reaction time, demonstrating to be a fast and reliable tool for the production of these [11C]radiopharmaceuticals for clinical use.