How is nicotine extracted from tobacco leaves and solubilized?
1 Answer
Here's what I get.
Explanation:
Nicotine is a colourless, oily liquid with a boiling point of 247 °C.
Its structure is
It is a base and exists in the plant as the salt of various acids.
We can represent the reaction as
#"Nic + HA" → "NicH"^"+" + "A"^"-"#
Here is a simplified version of the industrial process for extracting nicotine.
1. Cut the leaves to pass a 6 mm sieve.
2. Add a lime slurry to free the nicotine from its salts.
The reaction is
#"NicH"^"+" + "OH"^"-" → "Nic" + "H"_2"O"#
3. Heat the slurry with superheated, pressurized steam.
The process is effectively a steam distillation of the oil.
4. Condense the vapours.
5. Extract the nicotine from the condensate with kerosene.
6. Extract the nicotine from the kerosene with 25 % sulfuric acid.
#"2Nic(kerosene)" + "H"_2"SO"_4"(aq)" → ("NicH")_2"SO"_4"(aq")#
7. Use alkali to adjust the solution to pH 6 for safe transport in metal containers.