共查询到20条相似文献,搜索用时 78 毫秒
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以油茶饼粕为原料,采用乙醇提取-丙酮沉淀法对茶皂素进行提取分离。以茶皂素纯度和得率为考察指标,对乙醇体积分数、液料比、提取温度、提取时间、提取次数、提取液浓缩程度和丙酮用量等工艺参数进行了单因素优化。结果表明:体积分数95%的乙醇为提取溶剂,乙醇与预处理过的油茶饼粕液料比为9:1(mL:g),提取温度为70℃,提取时间为4 h,提取次数为2次,提取液浓缩至刚好有固体析出,丙酮用量为4倍浓缩液体积量时提取分离效果较佳,得到的茶皂素纯度为85.17%,得率为9.82%。不同溶剂打浆对产品纯化效果的比较发现:丙酮、乙酸乙酯、无水乙醇、体积分数95%的乙醇作为打浆纯化溶剂用于提高茶皂素纯度效果均不明显。 相似文献
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采用高效液相色谱(HPLC)法检测柠檬苦素类物质的含量,通过单因素实验考察了提取溶剂、溶剂体积分数、pH值、提取温度、提取时间、料液比对低温微波辐射辅助提取橘皮中柠檬苦素类物质的影响。结果表明:柠檬苦素质量浓度在11.52~57.60μg·mL-1范围内与色谱峰面积呈良好的线性关系,回归方程为A=10.9308016c-2.901838(R2=0.99969);在提取溶剂为80%乙醇、pH值为5、提取温度为50℃、提取时间为120min、料液比为1∶12(g∶mL)的条件下回流提取2次,橘皮中柠檬苦素的提取量达到0.856mg·g-1。得到的柠檬苦素类物质结构经红外光谱确认。 相似文献
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元宝枫绿原酸的超声提取方法研究 总被引:13,自引:1,他引:13
以乙醇溶液为溶剂 ,利用超声效应提取元宝枫叶中绿原酸 ,对超声强度 ,超声作用时间 ,料液比等因素进行研究。其较佳条件为 :室温下乙醇质量分数 3 0 % ,超声强度 2档 ,作用时间 15min ,料液比为 1∶16,提取次数2次。 相似文献
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葡萄籽中原花青素提取工艺研究 总被引:1,自引:0,他引:1
施立钦 《精细与专用化学品》2007,15(20):23-26
通过浸提的方法从葡萄籽中提取原花青素,考察了不同溶剂、浸提时间、浸提温度、乙醇体积分数和料液比等单因素对浸提效果的影响,确定了最佳的单因素水平。并通过正交实验,得出了原花青素提取的最佳工艺条件:乙醇的体积分数为70%,提取温度为50℃,料液比为1∶7(g/mL),提取时间为30min,提取次数为3次。 相似文献
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乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。 相似文献
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D. G. Gordeev L. F. Gudarenko M. V. Zhernokletov V. G. Kudel’kin M. A. Mochalov 《Combustion, Explosion, and Shock Waves》2008,44(2):177-189
A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation
of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from
the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO2) of density 0.08 g/cm3.
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Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008. 相似文献
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Jorge Marcelo Romero Soledad Bustillo Hugo Enrique Ramirez Maisuls Nelly Lidia Jorge Manuel Eduardo Gómez Vara Eduardo Alberto Castro Alicia H. Jubert 《International journal of molecular sciences》2007,8(7):688-694
A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out. 相似文献
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A perturbation viscometer is a differential capillary viscometer that measures the logarithmic viscosity gradient of the viscosity-composition curve for gas mixtures. Measurements are made at different gas mixture compositions. Integration of the logarithmic viscosity gradients measured over the full composition range gives the mixture viscosity relative to the viscosity of one of the pure components of the gas mixture. This method is attractive because, for measurements of equal precision, integration of the gradients is potentially an order of magnitude more precise than measurement of the viscosities directly. It can also work at high and low temperatures and perhaps high pressures.The perturbation viscometer has been used to make measurements on ideal gas mixtures at ambient and elevated temperatures. The situation is more complicated when the gas mixtures are non-ideal. Extra effects due to density differences, molar volume change on mixing and differential thermal expansion may be measured in addition to the desired viscosity change producing systematic errors in the results. Thus, a more sophisticated apparatus is required. The standard perturbation viscometer has been modified to separate out the extra effects to permit measurement of the true change in viscosity. In addition, the theoretical operation of the modified apparatus has been revised to account for the design changes to permit calculation of the viscosity-composition profiles from the results.The apparatus has been tested using helium-HFC-125 mixtures and two new viscosity-composition profiles are presented for these mixtures at 23 and . Internal consistency tests have been used to confirm that the data produced are of high quality with an estimated uncertainty in the viscosity ratio data at of 0.9% and at of 1.5%. 相似文献
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醋酸纤维素取代基分布与性质的关系 总被引:9,自引:0,他引:9
分析了以吡啶为溶剂的醋酸纤维素的13C-NMR核磁共振谱,得出了三种不同位置羟基的取代度。结合X—射线和DSC分析,初步说明具有相同取代度但未经水解和经过水解的醋酸纤维素(CA) 性质上的差异是由于三个羟基上的取代度分布不同及消晶程度差异所致。 相似文献