The alpha dicarbonyl compounds glyoxal and methylglyoxal will react with amine compounds such as amino acids and methylamine, all present in clouds and aerosol. These reactions are studied by NMR, SMPS, ESI-MS, and AMS at concentrations down to the uM range. Results indicate that stable N-derivatized imidazole and light-absorbing products form when lab-generated cloud droplets evaporate. Droplets containing either methylamine or methylglyoxal and a corresponding amine / carbonyl reaction partner also form oligomers upon drying with masses observed by HR-ToF-AMS up to m/z = 661. These irreversible processes convert volatile compounds into high-mass aerosol material and likely go to completion during and after a single cloud processing event. They also may be involved in the direct uptake of these compounds by aerosol. These reactions are the first reported pathway to stable organic aerosol material from methylamine, a compound with only one carbon.