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离子液体微波提取在中草药化学成分提取中的应用
Application of Ionic Liquid Microwave Extraction to Extracting Chemical Constituents from Traditional Chinese Medicines
【作者】 翟玉娟;
【导师】 于爱民;
【作者基本信息】 吉林大学 , 分析化学, 2010, 博士
【摘要】 本论文以绿色溶剂离子液体作为微波吸收介质,对微波提取中草药干燥植物样品中化学成分的方法进行改进研究,以达到快速、简便对目标样品化学成分定性的目的。通过实验,对已有的微波提取方法进行改进,自行组装了新的提取装置,最终建立了两种全新的微波提取模式。论文主要包括以下几个部分:离子液体微波提取法,微波提取顶空单滴微萃取法,微波提取顶空取样法和离子液体非极性溶剂微波提取法。在离子液体微波提取法中,以离子液体作为微波吸收介质代替传统的水、有机溶剂以及羰基铁粉等加入到提取体系中,对加入固体微波吸收介质的无溶剂微波提取法进行了改进。离子液体作为一种新型的介质,具有很强的微波吸收能力。因此,离子液体微波提取法具有提取更快、更高效的优势。并且,干燥植物样品不需要任何前处理,在离子液体加入到微波提取体系后,不需要搅拌就可直接提取,使实验更加简便易行。在微波提取顶空单滴微萃取法中,离子液体和羰基铁粉分别作为该方法的微波吸收介质。通过自行设计的提取装置,使用微量溶剂在顶空提取,并且微波吸收介质不与样品混合就可直接对样品进行加热。本实验不但简便、快速、样品用量极少,而且具有微波吸收介质可以循环使用的优点。微波提取顶空取样法是微波提取顶空单滴微萃取法的改进。同样,也是应用离子液体和羰基铁粉作为微波吸收介质。其提取装置与微波提取顶空单滴微萃取法的提取装置基本相似,但在该方法中不使用任何溶剂,当微波提取完成后,进行顶空取样直接测定,不但减少了溶剂浪费,并使提取速度进一步提高。离子液体非极性溶剂微波提取法是对非极性溶剂微波提取法的改进。离子液体作为微波吸收介质代替传统有机溶剂、固态微波吸收介质(羰基铁粉和石墨),用非极性溶剂对人参中的化学成分进行了提取。实验结果表明,离子液体可以作为一种新型的微波吸收介质在非极性溶剂提取中应用。
【Abstract】 In this thesis, the Ionic liquid(IL) was used as the microwave absorption medium and applied to the extraction of essential oils from dried traditional Chinese medicines by microwave assisted extraction (MAE). A new microwave heating mode was applied in MAE, and new microwave extraction method was developed.ILs were very suitable for MAE because the ILs can rapidly and effectively absorb the microwave energy. Adding the IL into the extraction system can improve the speed of extraction process. By adding ILs as MAM into samples, the microwave-assisted extraction (ILME) was developed. In another method, ionic liquid and carbonyl iron powder were used as MAMs, the MAM did not mix with the sample and can be reused. Headspace single drop micro-extraction (HS-SDME) coupled with microwave extraction (ME) was developed.The IL was applied to the extraction of essential oils from the dried fruits of the Illicium Verum Hook. f., Cuminum Cyminum L., Cinnamomum cassia Presl and Forsythia suspensa (Thunb.) Vahl by ILME. The proposed method offers a simple, rapid and efficient sample preparation for determination of essential oils in dried plant materials by GC/MS. The extraction time was less than 18 min at the microwave power of 440 W and 1.5mL of ionic liquid was required. Compared with traditional HD, the ILME makes the process more simple and more advantageous in respect of extraction time and sample consumption. Compared with conventional MAE, the green solvent IL was added into the extraction system and little solvent was used in the proposed method. Compared with SFME, the proposed method is simpler and more time-saving because when SFME was applied, for dried materials it was necessary to moisten the sample before extraction. Compared with ISFME, in the ILMAE the IL and sample is an homogenous mixture and the stirring is not required, which makes the extraction system simpler and operation easier.Headspace single drop micro-extraction (HS-SDME) coupled with microwave extraction (ME) and microwave extraction headspace (ME-HS) were developed in order to extract the essential oil from dried Syzygium aromaticum (L.) Merr. Et Perry, Cuminum cyminum L., Cinnamomum cassia Presl and Zingiber Officinale Rosc.. Ionic liquid and carbonyl iron powder were used as microwave absorption medium. The extraction time was less than 7 min at the microwave power of 440 W. 10uL of decane was used as micro-extraction solvent in ME-HS-SDME. The proposed methods were compared with hydrodistillation (HD). There are not obviously different in the constituents of essential oils obtained by the two methods. In the ME-HS-SDME and ME-HS, the best advantage is that MAM can be recycled and are not in contact with the samples.The IL was used as the MAM by adding the sample and ionic liquid-non polar solvent microwave extraction (ILNPSME) was developed. The proposed method was applied to the extraction of the chemical constituents from the root of Panax ginseng C.M.Mey.. The ILNPSME was compared with solid microwave absorption medium-non polar solvent microwave extraction (SMAMNPSME), polar solvent microwave extraction (PSME) and combined solvent microwave extraction (CSME). PSME is suitable to the extraction of polar constituents. The main chemical constituents obtained by SMAMNPSME and ILNPSME are similar, which indicates that the IL can act as an microwave absorption medium and energy translation material.The proposed method has the advantages, such as short extraction time, simple operation and use of green solvent, and is a suitable method to extract the chemical constituents from plant meterials.