THE SYSTEM: NICOTINE – METHYLETHYL KETONE – WATER

The systems: nicotine–water and nicotine – methylethyl ketone were investigated by thermal analysis but the eutectic points were not obtained due to the extreme viscosity and consequent supercooling of solutions of high nicotine content.The densities, viscosities, and refractive indices were determined for the nicotine – methylethyl ketone – water system at 25.0 °C.The mutual solubilities of nicotine, methylethyl ketone, and water were determined over the entire temperature range. A ternary critical point was found at 67.3 °C, the critical composition being 27 weight per cent nicotine; 14 weight per cent methylethyl ketone.The methylethyl ketone – water and nicotine–water solubility curves were redetermined. The existing data for the former system were confirmed but the data for the classical system nicotine–water were found to be seriously in error at the higher critical solution temperature. Thus the lower critical solution temperature was found to be 61.5 °C, in good agreement with previous figures, but the upper critical solution temperature lies at 233.0 °C, some twenty degrees higher than had been obtained by previous workers; the corresponding critical compositions are 36% and 40% nicotine respectively.