Extraction And Purification Of Nicotine In Tobacco

A fast and stable method of determining nicotine—non-aqueous titration method was improved. Technics of extracting nicotine from tobacco and making unrefined product of nicotine was studied and determined; The unrefined nicotine was purified using solvent extraction and the nicotine was refined by a salification reaction of nicotine and palmitic acid.The content of nicotine in tobacco was determined with non-aqueous titration. Compared with the method using HPLC, non-aqueous titration was more stable, more convenient and faster, and the accuracy and sensitivity of the method were satisfying, especially fitted for fast and mass analysis of nicotine of tobacco sample in medium-sized and small companies. This is a method worth of wide use.Though single factor selecting expriment and orthogonal test,The optimal technics of extraction of nicotine with microwave assisted extraction was determined: microwave radiation time was 6 min, microwave power was 600W and the proportion of material and solvent was 1:25.The technics of making unrefined nicotine from tobacco solution was as follows: first extraction with chloroform for 15 min, the proportion of chloroform and solution was 1:1, the extraction was repeated once. The nicotine was then reextracted with sulfuric acid for two times, 10 min every time, and the proportion of the two phases was also 1:1.The nicotine was purified with solvent extraction. Hexane was chosen as the extraction solvent. The optimal condition was as follows: the proportion of the two phases(hexane/ water) was 2:1, extraction time was 15 min, and the extraction was repeated thee times. The purity of nicotine was 95% and the yield was 38%.The nicotine was refined by salification reaction using palmitic acid and nicotine, the optimal condition was as follows: 5 mL of nicotine was dissolved in 20 mL of hexane, the amount of palmitic acid was 1.5 g, reaction time was 6 h, the proportion of hexane and water was 1:2(V/V) and the optimal reaction temperature was 40℃. The purity of nicotine was 98.8%.Products in different extraction steps were analyzed with GC/MS. The results showed that after a serial of extraction and purification, the concentration of nicotine increased a lot. The purity of nicotine in final product was 98.8%, reaching the requirement of medication product. The proportion of other tobacco alkaloids, like anatabine,myosmine in products lower a lot.