三相萃取及气助三相萃取分离大黄中的蒽醌类物质
文献类型：学位论文
| 作者 | 杨兴福 |
| 学位类别 | 硕士 |
| 答辩日期 | 2013-04-01 |
| 授予单位 | 中国科学院研究生院 |
| 导师 | 刘会洲 ; 梁向峰 ; 杨良嵘 |
| 关键词 | 液－液－液三相萃取 分离 大黄素 大黄酸 气助三相萃取 |
| 其他题名 | Three-Liquid-Phase Extraction and Gas-Assisted Three-Liquid-Phase Extraction of Anthraquinones from |
| 学位专业 | 化学工程 |
| 中文摘要 | 聚合物液－液－液三相体系是由有机萃取剂、聚合物、无机盐和水组成的基于界面现象的微乳萃取体系。该体系可在温和条件下实现多种组分一步选择性分离，近年来受到了国内外学者广泛关注。本论文以中草药大黄中两种结构类似的蒽醌化合物大黄素和大黄酸的提取分离为模型，考察了大黄素和大黄酸在聚合物三相体系中的分配行为及其影响因素，实现了两种蒽醌化合物的一步选择性分离，并探究了大黄素和大黄酸在新型的气助三相萃取体系中的分离富集行为。 本论文构建了有机萃取剂－聚合物－盐水溶液三相体系，探索了萃取剂种类、聚合物种类、pH、聚合物和盐的浓度对聚合物三相体系萃取分离模拟大黄蒽醌提取液中大黄素和大黄酸的影响，结果表明，萃取剂种类和pH对两种溶质在主体相中的分配具有重要影响。应用分子模拟和傅里叶红外等手段，发现疏水相互作用和氢键是三相萃取的主要作用力。在15%甲基异丁基酮，10%聚乙二醇4000，10%(NH4)2SO4体系中当pH=8时，95%的大黄素萃取到有机上相，97%的大黄酸萃取到聚合物中相。通过调节pH进行反萃，大黄素和大黄酸的一次反萃率均达到97%以上。在模拟体系确定的工艺条件下，考察了实际体系中大黄素和大黄酸的分离效果，约91%的大黄素分配到上相，86%的大黄酸萃取到中相。 为了强化液－液－液三相萃取分离，本论采用气助三相萃取分离富集了大黄提取液的蒽醌组分。在由乙酸丁酯－聚乙二醇－硫酸铵水溶液体系构建的三相萃取体系中，探索了气流速度、通气时间、盐浓度、萃取剂和聚合物初始加入量对大黄素和大黄酸分离富集的影响。提高气流速度和盐浓度，有助于提高分离效果，减少操作时间；聚合物加入量对蒽醌分离的影响较乙酸丁酯更大。以30 mL/min的气流速度通气50 min，水相中大黄素和大黄酸的移除率可分别达到99%和97%，乙酸丁酯相大黄素的质量分数和聚乙二醇中大黄酸的质量分数可分别达到97%和95%，大黄素和大黄酸的富集因子分别达到15和30。与液－液－液三相萃取相比，气助三相萃取的强化了三相萃取的传质过程，消耗更少的萃取剂，较大幅度地提高了大黄素和大黄酸的分离因子和富集因子。 |
| 英文摘要 | Three-Liquid-Phase system (TLPS), which is composed of organic extractant, polymer and brine, is a kind of micro-emulsion extraction system based on the interfacial phenomena. Because the choice of its phase forming components is extensive and physicochemical properties of the system can be easily tuned. Hence TLPS is regarded as a promising technique which could achieve highly-selective separation performance under mild operation condition with simple process. In recent years, TLPS has increasingly attracted researchers’ attention and is been extensively studied. In this thesis, with the model of extraction and separation of anthraquinone compounds from Rhubarb, a kind of traditional Chinese herbal medicine, the partitioning behaviors of emodin and rhein, two typical anthraquinones in Rhubarb, were systematically investigated under various conditions in TLPS, and selective separation of two structure-similar compounds in one step was successfully achieved. Furthermore, the novel gas-assisted three-liquid-phase extraction (GATE) was applied to simultaneous separation and concentration of emodin and rhein, and various operation parameters affecting the process were investigated. To simplify the experimental process, various organic extractant-polymer-inorganic salt aqueous solution systems were constructed to separate emodin and rhein from each other in simulated Rhubarb extract. Effects of various factors, such as extractant type, polymer type, solution pH, concentration of polymer and ammonium sulphate on the partitioning of emodin and rhein were studied. Among them, extractant type and pH played an important role on the partitioning behavior of the two anthraquinone compounds while the effects of other parameters were relatively moderate. With the assistance of molecular simulation programs and FT-IR spectrum, hydrophobic interaction and intermolecular interaction were recognized as major driving forces to affect the partitioning behaviors of emodin and rhein. Under optimized condition, 95% emodin and 97% rhein could be simultaneously extracted into the top and middle phase, respectively, and separation factor over 10000 of the two anthraquinones was achieved. Using methyl isobutyl ketone and sodium hydroxide aqueous solution as back extraction medium, both emodin and rhein could be conveniently back extracted by adjusting pH, the one-step back extraction efficiency of both emodin and rhein could be approximately 97%. With the same optimized condition obtained in the separation of simulated extract, emodin and rhein could be well separated in one step from the Rhubarb extract in the methyl isobutyl ketone-PEG4000-ammonium sulphate solution system. The results showed that approximately 91% of emodin distributed into methyl isobutyl ketone phase while about 86% of rhein extracted into polymer phase. In a GATE system composed of butyl acetate-PEG4000-ammonium sulphate aqueous solution, influence of various parameters including gas flow rate, flotation time, salt concentration, initial volume of PEG and butyl acetate were investigated in the optimization of separation and concentration of emodin and rhein from simulated Rhubarb extract. Appropriate increase of gas flow rate and concentration of salt is conducive to improve separation performance and reduce operation time. Due to directly contacting with aqueous phase, initial volume of PEG has a more significant influence than that of butyl acetate. Within 50 minutes of 30 mL/min nitrogen flow, removal ratio of emodin and rhein from aqueous phase could be over 99% and 97%, respectively. Mass fraction of emodin in the butyl acetate phase and rhein in the PEG phase could reach 97% and 95%, respectively. Experiment results demonstrated that separation ratio and concentration coefficient of GATE are significantly higher than TLPS because of higher phase ratio between aqueous phase and extractant phase. The results also demonstrated that GATE provided higher treatment capacity and consumed less PEG phase and organic phase compared with traditional TLPS. |
| 语种 | 中文 |
| 公开日期 | 2014-06-26 |
| 页码 | 101 |
| 源URL | [http://ir.ipe.ac.cn/handle/122111/8360]  |
| 专题 | 过程工程研究所_研究所（批量导入） |
| 推荐引用方式 GB/T 7714 | 杨兴福. 三相萃取及气助三相萃取分离大黄中的蒽醌类物质[D]. 中国科学院研究生院. 2013. |
入库方式： OAI收割
来源：过程工程研究所
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