Ng Lay-Keow, Hupé Michel
Laboratory and Scientific Services Directorate, Canada Customs and Revenue Agency, 79 Bentley Avenue, Ottawa, Ontario, Canada K1A 0L5.
J Chromatogr A. 2003 Sep 5;1011(1-2):213-9. doi: 10.1016/s0021-9673(03)01178-6.
The effects of tobacco moisture on nicotine yield were investigated in this study. Soxhlet and microwave-assisted techniques were used to extract nicotine from cigar fillers of varying moisture contents (5-20%), using a polar (methanol) and a non-polar (isooctane) solvent. The extracts were analyzed by a gas chromatograph equipped with a flame-ionization detector. For both extraction techniques, higher nicotine yields were consistently obtained with methanol than with isooctane from the same samples. Solubility of nicotine salts in methanol but not in isooctane is the major cause of this observation. Moreover, pronounced effects of the tobacco moisture content on extraction efficiency were observed with isooctane but not with methanol. For microwave assisted extraction (MAE) with isooctane, nicotine yield increased from 3 to 70% as the moisture level in tobacco was raised from 3 to 13%, and leveled off thereafter. Similar observations were made with Soxhlet extraction. While MAE results were rationalized by the known cell-rupture process, a mechanism based on the interaction between the solvents and the structural components of the plant cells has been proposed to account for the observations made with Soxhlet extraction.
本研究考察了烟草湿度对尼古丁产率的影响。采用索氏提取法和微波辅助提取技术，使用极性溶剂（甲醇）和非极性溶剂（异辛烷）从不同湿度（5%-20%）的雪茄烟丝中提取尼古丁。提取物通过配备火焰离子化检测器的气相色谱仪进行分析。对于这两种提取技术，从相同样品中用甲醇提取得到的尼古丁产率始终高于用异辛烷提取的产率。尼古丁盐在甲醇中可溶而在异辛烷中不溶是这一现象的主要原因。此外，观察到烟草湿度对异辛烷的提取效率有显著影响，而对甲醇则没有。对于用异辛烷进行的微波辅助提取（MAE），随着烟草湿度从3%提高到13%，尼古丁产率从3%增加到70%，此后趋于平稳。索氏提取也有类似的观察结果。虽然MAE的结果可以通过已知的细胞破裂过程来解释，但已提出一种基于溶剂与植物细胞结构成分之间相互作用的机制来解释索氏提取的观察结果。
