本文選題：生育酚同系混合物 + 聚合物萃取劑　； 參考：《浙江大學(xué)》2015年碩士論文

【摘要】：天然產(chǎn)物中的同系物因具有高度相似的結(jié)構(gòu)和性質(zhì),其分離極具挑戰(zhàn)。生育酚作為最有代表性的天然產(chǎn)物之一,含有α-、β-、γ-和6-生育酚四種同系物,它們的生物活性為δ-γ-β-α-生育酚,因此,從生育酚的同系混合物中分離α-生育酚具有重要的經(jīng)濟價值。鑒于現(xiàn)有生育酚同系混合物萃取分離溶劑體系的低分離效率和選擇性,考慮到其同系物酸性的差異,我們首次提出以含有胺基的聚合物為萃取介質(zhì),用于生育酚同系混合物的萃取分離。為此,我們制備了三種不同分子量的甲基丙烯酸二甲氨基乙酯的均聚物(PDMAEMA),與乙腈(ACN)組成萃取劑體系,與用純ACN作為萃取劑相比,生育酚在PDMAEMA萃取劑體系中的分配系數(shù)和選擇性系數(shù)都明顯提高。PDMAEMA30-ACN(ω(PDMAEMA)=38.9%)為萃取劑時,6-生育酚的分配系數(shù)是ACN作萃取劑時的4.4倍,6-對a-生育酚的選擇性系數(shù)是ACN作萃取劑時的1.6倍。我們進一步以支化聚乙烯亞胺(PEI)為萃取介質(zhì),分別考察了助溶劑的種類、PEI分子量和濃度對萃取的影響。當(dāng)以PEI-ACN為萃取劑體系時,生育酚表現(xiàn)出良好的分配和選擇性。PEI上胺基與ACN的摩爾比為0.485時,δ-生育酚的分配系數(shù)為7.05,相應(yīng)δ-對α-生育酚的選擇性系數(shù)為5.92。同時,研究發(fā)現(xiàn)PEI對C02刺激有很好的響應(yīng)能力,可用于萃取相中生育酚的快速回收：萃取相中通CO2,僅需正己烷3次反萃就可回收生育酚超過90%；而不使用COz,理論上需要正己烷反萃12次,生育酚的回收率才能達到90%。經(jīng)回收生育酚后的PEI萃取相通過加熱和通N2,可釋放出CO2重新作為萃取劑使用,經(jīng)循環(huán)使用3次測試,生育酚的分配系數(shù)僅下降約10%,選擇性系數(shù)幾乎不變。由于PEI對生育酚具有良好的萃取選擇性,我們進一步以二氧化硅負載的PEI為吸附劑,研究了采用吸附法從生育酚同系混合物中分離α-生育酚,同樣獲得了很高的生育酚吸附率和分離因子。吸附劑的質(zhì)量與生育酚同系混合物溶液的體積之比為0.4g/mL時,δ-生育酚的吸附率為96.1%,δ-和α-生育酚的分離因子可達12.1。吸附生育酚后的二氧化硅負載的PEI可在ACN或者乙醇中高效脫附。
[Abstract]:The separation of homologues in natural products is challenging due to their highly similar structures and properties.As one of the most representative natural products, tocopherol contains four homologues of 偽 -, 尾 -, 緯-and 6-tocopherol. Their biological activity is 未-緯-尾-偽 -tocopherol. Therefore, the separation of 偽 -tocopherol from tocopherol mixture has important economic value.In view of the low separation efficiency and selectivity of the existing extraction and separation solvent systems for tocopherol mixtures and considering the difference in the acidity of their homologues, we proposed for the first time that polymers containing amino groups should be used as the extraction medium.It is used for extraction and separation of tocopherol homologous mixture.For this reason, we have prepared three kinds of homopolymer of dimethylaminoethyl methacrylate with different molecular weight, PDMAEMAN and acetonitrile (acetonitrile) as extractant system, compared with pure ACN as extractant.The partition coefficient and selectivity coefficient of tocopherol in PDMAEMA extractant system were obviously increased. The partition coefficient of tocopherol was 4.4 times as high as that of ACN as extractant, and the selectivity coefficient to a- tocopherol was 1.6 times higher than that of ACN as extractant.We further investigated the effects of molecular weight and concentration of PEI on the extraction with branched polyethyleneimide (PEI) as the extraction medium.When PEI-ACN was used as extractant, tocopherol showed good distribution and selectivity. The molar ratio of amino group to ACN was 0.485, the partition coefficient of 未 -tocopherol was 7.05, and the selectivity coefficient of 未-to 偽 -tocopherol was 5.92.At the same time, the study found that PEI has a good response to CO2 stimulation,It can be used for quick recovery of tocopherol in extraction phase. In extraction phase, the recovery rate of tocopherol can be more than 90 by only 3 times stripping of n-hexane, but without using COz. in theory it needs 12 times of n-hexane to recover tocopherol, and the recovery rate of tocopherol can reach 90%.After the recovery of tocopherol, the PEI extraction phase can release CO2 to be used as extractant by heating and passing through N _ 2. The distribution coefficient of tocopherol is only decreased by about 10% and the selectivity coefficient is almost unchanged after three times of recycling test.Because PEI has good selectivity for extraction of tocopherol, we further studied the separation of 偽 -tocopherol from tocopherol homologous mixture by using silica supported PEI as adsorbent.The high adsorption rate and separation factor of tocopherol were also obtained.When the mass ratio of adsorbent to the volume of tocopherol homologous solution is 0.4g/mL, the adsorption rate of 未 -tocopherol is 96.1, and the separation factor of 未-and 偽 -tocopherol is 12.1.PEI supported on silica after adsorption of tocopherol can be desorbed efficiently in ACN or ethanol.
【學(xué)位授予單位】：浙江大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TQ028;TQ28

【參考文獻】

相關(guān)博士學(xué)位論文 前1條

1 張祺;二氧化碳刺激響應(yīng)的可逆凝聚與再分散膠乳的研究[D];浙江大學(xué);2012年

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本文編號：1756101