正交试验优化逆三相膜萃取烟碱的工艺研究

Research on optimization reverse phase membrane extraction of nicotine with orthogonal method

目的优化逆三相膜萃取烟叶中烟碱的提取工艺。方法采用聚四氟乙烯膜(PTFE)作为萃取膜,硫酸溶液作为酸相、氢氧化钠溶液作为碱相、氯仿作为有机相的逆三相膜萃取循环系统萃取烟碱叶中烟碱。依据烟碱在261 nm处有特征吸收,采用紫外分光光度计检测烟碱叶中游离烟碱的含量。以烟碱萃取率为指标,考察酸浓度、碱浓度、循环时间、酸碱水相及有机相体积比和流速5个因素,选定最佳工艺。结果提取烟叶中烟碱的最佳提取工艺条件为:酸浓度0.01%,碱浓度5%,循环时间25 min,体积比(酸碱相∶有机相)2.5∶1,流速6 m L/min,烟碱的提取率达到99.07%。对正交试验数据进行统计分析,差异有统计学意义(P<0.05)。按最佳工艺进行3次重复实验,结果显示烟碱提取率均值达到99.01%。结论该工艺操作简单,萃取时间快,有机溶剂的消耗量少,易实现工业化,环境污染少,适用于烟叶中烟碱的提取。

Objective To optimize extraction process of nicotine from tobacco leaves by reverse phase membrane.Methods Using PTFE membrane as extraction membrane,sulfuric acid solution as acid,sodium hydroxide solution as the alkali phase,chloroform as organic phase,the extraction of nicotine from nicotine leaves was carried out by reverse phase membrane extraction and circulation system. According to the characteristics of nicotine on 261 nm UV absorption,UV spectrophotometer was used to determine free nicotine content in nicotine leaves. The orthogonal design optimization of 5 factors and 4 levels L16（ 4^5） was investigated,nicotine extraction rate as the index,inspection concentration of acid,alkali concentration,cycle time,acid and alkali phase and organic phase volume ratio and flow rate on the influence of the nicotine extraction. Results The best extraction conditions of extracting nicotine in tobacco leaf are acid concentration 0. 01%,alkali concentration 5%,cycle time 25 min,volume ratio（ acid-base phase： organic phase） 2. 5∶ 1,the velocity 6 m L / min. The nicotine extraction rate reached99. 07%. Orthogonal test data statistical analysis expressed（ P〈 0. 05）,which has significant differences. Repeated experiments were carried out three times under the best extraction conditions. The optimal combination of repetitive experimental results showed that the average nicotine extraction rate reached 99. 01%. Conclusion The process is simple,and extraction time is short,and consumption of organic solvent is low. It is easy to realize industrialization with less pollution and suitable for the extraction of nicotine from tobacco.