| 摘要 |
A process is provided for the selective removal of basic materials from plant products, in particular, for removing nicotine from tobacco without materially affecting the content of the other components of the tobacco. Tobacco is traversed with a solvent at high pressure and in a physical state which is either a liquid at a pressure of from about 500-300 atmospheres or a supercritical fluid wherein nicotine and the other components dissolve in the solvent. As the single means of removing substances from the solvent, the solvent is then passed through an acid-containing trap where the solvent is essentially freed of nicotine. The solvent, depleted of nicotine and enriched in the other components, is then recycled to the tobacco to reextract nicotine. In addition, the tobacco may be pretreated with a chemical base which does not substantially react with the tobacco components under ambient conditions and which are not necessarily affected by the process conditions but are nonetheless effective in increasing the amount of nicotine which can be extracted by the process of this invention. Pretreatment of the tobacco with a chemical base neutralizes nicotine salts and permits the extraction process to be carried out under milder conditions.
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