Recovery and purification of nicotine from waste tobacco by aqueous two-phase system/reverse extraction.

A two-step process has been developed for the purification of nicotine from waste tobacco using an aqueous two-phase system and solvent reverse extraction. The partitioning behavior of nicotine was investigated in an isopropyl alcohol/(NH4)2SO4 aqueous two-phase system. The effects of the addition of salt, pH and temperature on the partitioning behavior of nicotine were studied. The recovery rate of nicotine was 96.1% with a purity of above 99% when optimal conditions were used [(NH4)2SO4 25%, pH 9, temperature 35 degrees C, isopropyl alcohol 5 mL].