共查询到20条相似文献,搜索用时 109 毫秒
1.
2.
3.
4.
《广州化工》2016,(7)
探讨了桃树叶中黄酮的提取方法,研究了溶剂浸提温度、时间、固液比、乙醇浓度,超声波或微波辅助等对桃叶中黄酮提取效果的影响。研究结果表明:溶剂浸提中,影响因素依次为:料液比乙醇浓度浸提温度水浴时间;超声波辅助提取中则为乙醇浓度料液比浸提温度超声时间;微波提取中则又为微波时间微波功率料液比乙醇浓度。用70%乙醇作为浸提溶剂,料液比1∶25,温度控制在30℃,1次浸提40 min,桃叶黄酮提取率1.81%;采用超声波辅助提取,料液比为1∶30,浸提温度控制在50℃,提取30 min,用70%乙醇提取桃叶黄酮,提取率最高达3.98%;使用微波辅助提取时,料液比1∶30,微波功率控制在200 W,用60%乙醇提取30 s,则黄酮提取率3.92%。由此可见,纯粹用溶剂提取,提取率较低,不到2%,采用超声波或微波辅助提取,可达近4.0%。 相似文献
5.
6.
采用水-乙醇作提取溶剂回流提取了银杏叶中的银杏黄酮.设计正交实验确定影响提取银杏黄酮的显著因素为料液比、乙醇浓度、提取温度.单因素实验确定提取工艺的最佳条件为料液比1:10,乙醇浓度70%,提取温度70℃,粒度40~80目,回流提取时间为2h.银杏黄酮的提取率达到86.5%. 相似文献
7.
8.
本文采用超声波提取,紫外分光光度计测定样品中黄酮含量,考察乙醇浓度、提取时间、料液比、提取温度四个因素对黄酮提取率的影响,采用L_9(3~4)正交试验法,优化黄酮化合物的最佳提取工艺。实验结果:最佳提取工艺为70%的乙醇、提取时间40min、料液比1∶15,提取温度为60℃,在此条件下总黄酮提取率为5.96%。 相似文献
9.
从银杏叶中提取银杏黄酮的研究 总被引:4,自引:0,他引:4
采用水-乙醇作提取溶剂回流提取了银杏叶中的银杏黄酮.设计正交实验确定影响提取银杏黄酮的显著因素为料液比、乙醇浓度、提取温度.单因素实验确定提取工艺的最佳条件为料液比110,乙醇浓度70%,提取温度70℃,粒度40~80目,回流提取时间为2h.银杏黄酮的提取率达到86.5%. 相似文献
10.
11.
12.
13.
14.
15.
鸡心、鸡血中抗氧化物的提取及其活性研究 总被引:2,自引:0,他引:2
从鸡心、鸡血中提取抗氧化物 ,并分别利用邻苯三酚 (PR)自氧化法、碘量法对其活性进行了检测。结果表明 :鸡心提取物比鸡血提取物的抗氧化活性强。 相似文献
16.
Dave DeSimone Natasha Ghezawi Thomas Gaetjens Robert Counce Jack Watson 《溶剂提取与离子交换》2013,31(6):422-434
ABSTRACTExtraction of yttrium (Y) from sulfuric acid was studied using di(2-ethylhexyl) phosphate (DEHPA). A portion of the organic phase was recycled back into the mixer after extraction for the mixer to operate at a moderate organic-to-aqueous volumetric phase ratio while processing at a low organic-to-aqueous flow rate ratio. The effective performance of the mixer was evaluated when operating at different organic-phase flow fractions. To model the extraction rate coefficient, a 2-factor designed experiment was performed by conducting both equilibrium and mixer-settler tests. The organic-phase flow fraction was varied over four discrete levels while the extractant concentration was varied over three discrete levels. Increasing the organic-phase flow fraction yielded a continual increase in the extraction rate coefficient. In contrast, increasing the extractant concentration yielded an initial increase followed by a subsequent decrease in the extraction rate coefficient. The decline in the extraction rate coefficient was attributed to a decrease in the yttrium-extractant complex’s diffusion coefficient. High metal loading caused an elevated organic-phase viscosity and thus the low diffusion coefficient. An extraction rate coefficient model is proposed to describe the effects of extractant concentration, viscosity and organic-phase flow fraction. Mass transfer resistance was largely in the organic phase. 相似文献
17.
18.
19.