以稻草秸秆为原料制得生物油,用高纯水提取生物油中有效成分,提取液经活性炭和无机碱(Ca(OH)2或NaOH)脱除胶体和酸性物质等,用乙酸乙酯和水的混合液(V/V,2:1)提取生物油中内醚糖,再经乙酸乙酯分离纯化,得内醚糖晶体.为获得更好的提取率,采用响应面曲面分析对内醚糖分离性能作优化研究.以高纯水体积、活性炭质量、pH为自变量,内醚糖浓度为因变量,建立了二者间的多元化数学回归模型,研究因素间的影响规律及通过Design Expert 8.0.6确定最优分离参数组合:高纯水:生物油=1:1(V/V)、活性炭:生物油=0.05:1(m/V).经验证,采用响应面曲面分析法所得内醚糖分离参数是可行的.通过FTIR,HPLC和NMR等分析,所获得的内醚糖收率可高达58%,且纯度在98%以上.实验为生物油中内醚糖的分离技术进一步研究提供了理论基础和科学依据,亦建立了一种快速,灵敏分析生物油中内醚糖的分析方法.%Bio-oil was produced from straw and further extracted with pure water. The extract was treated with active carbon and metal hydroxide (NaOH or Ca(OH)2) to remove organic colloid, pigments and aromatic compounds. EtOAc and water were used (V/V, 2:1) to extract crude levoglucosan which was further purified with EtOAc to obtain levoglucosan. RSM (response surface methodology) was employed to optimize levoglucosan separation. Water volume, active carbon weight and pH were considered as the independent variables, and levoglucosan concentration was the responsive variable. The relationship between the independent variables and dependent variable was explored by RSM. Mathematical regression model was established using Design Expert 8.0.6. The optimal combination of these parameters is found as pure water:bio-oil = 1:1 (V/V), active carbon:bio-oil = 0.05:1 (m/V). The results show that RSM is an appropriate approach for levoglucosan separation optimization. FTIR,HPLC and NMR results show that the optimal extraction yield of levoglucosan from the straw bio-oil is 58% with purity over 98%. This investigation provides a theoretical study for further research of levoglucosan separation from bio-oil. Furthermore, a fast and sensitive method is established for quantitative and qualitative analysis of levoglucosan.
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