超临界乙醇萃取蒽的实验研究

以乙醇为超临界萃取剂,采用恒容升温法研究了超临界乙醇对煤焦油中重要组分蒽的萃取效果,探究了温度和压力对萃取效果的影响。结果表明,在270~275℃,萃取压力为15.5 MPa左右时,萃取效果达到66%。实验表明,温度和压力对超临界乙醇萃取蒽有明显的影响。     

超临界乙醇萃取苯酚的实验研究

以乙醇为超临界溶剂,采用恒容升温法研究了超临界乙醇对苯酚的萃取效果,探讨了温度和压力对萃取效果的影响。结果表明,在萃取温度为270~275℃,萃取压力为13 MPa左右时,萃取效果明显,萃取率达62%以上,苯酚在超临界乙醇中的质量浓度为0.015 657 g/mL,实验效果明显。研究得出,温度与压力对固体物质的超临界溶解度具有明显的选择调节性。     

超临界乙醇萃取萘的实验研究

采用恒容升温法研究了超临界乙醇萃取煤焦油重要组分萘的效果,讨论了萃取温度和压力对萃取效果的影响.结果表明,在温度为270℃、压力为13MPa时,萘的超临界浓度为1.739×10^-2g/mL、萃取率为66.20％.     

萘油组分的超临界萃取工艺研究

以乙醇为超临界萃取剂,利用恒容升温法对綦油组分中的萘、苊和芴进行超临界萃取工艺研究,对萃余液进行气相色谱检测,通过差量法计算其萃取率和超临界浓度,结果表明,超临界乙醇对萘油组分的萃取具有较好的效果,在萃取温度为270℃、萃取压力为13MPa时,萃取效果最好;萘、苊、芴3种物质超临界萃取规律明显;萘油组分的超临界乙醇萃取工艺绿色环保,切实可行。     

洗油中喹啉的超临界萃取分离研究

在恒容反应器内,选用乙醇作超临界萃取剂萃取喹啉,研究了温度和压力对喹啉试剂萃取效率的影响。结果表明:萃取温度在260℃~270℃,萃取压力7.0 MPa~11.0 MPa,喹啉试剂的萃取效果较好。在此基础上,进一步研究了超临界乙醇萃取粗喹啉产物中喹啉时,压力和溶质溶剂体积比对萃取分离的影响,结果表明:萃取压力7.3 MPa,溶质溶剂体积比0.05,萃取温度为260℃时,最佳分离比率可达到1.85。     

超临界CO2络合萃取乳酸钙中痕量重金属离子的研究

以乙醇为改性剂,超临界CO2络合萃取乳酸钙中痕量重金属离子.考察了络合剂种类及用量、乙醇用量、温度、压力、萃取时间等对萃取效果的影响.结果表明,不同络合剂对不同金属离子的萃取效果有明显差异;乙醇用量对金属离子的萃取效果影响不明显;温度在50℃时,金属离子总萃取率可达80%以上;萃取时间比萃取压力的影响更为显著,表明络合反应控制着该过程.确定优化的萃取工艺条件如下:10 mL乙醇作改性剂、温度50℃、CO2流速13 L·h-1、压力20 MPa、萃取时间90 min、二乙基二硫代氨基甲酸钠与四丁基溴化铵复配物用量为样品质量的2%.     

超临界乙醇抽提粗酚的工艺研究

通过超临界乙醇萃取苯酚、邻甲酚、间/对甲酚四元组分,探究温度和压力对超临界萃取效果的影响。对萃取产物进行气相色谱检测分析,通过测定各组分的超临界质量浓度和萃取率,探究粗酚各组分在超临界乙醇中的溶解规律。结果表明,在模拟粗酚实验中,各组分的抽提规律较为接近,均在温度为275℃、压力为14 MPa时,超临界抽提效果最佳,此时,苯酚、邻甲酚和间/对甲酚的萃取率分别为63.72%、63.37%、64.42%。实际粗酚与模拟粗酚各组分萃取率相近,误差均控制在7%以下。所以通过萃取模拟粗酚四元组分以探究实际粗酚的抽提规律的方法是有效可行的。     

超临界CO2萃取烟草中烟碱

为研究超临界CO2萃取烟草中烟碱的工艺条件,利用实验室超临界萃取装置对烟草中烟碱进行了提取,考察了萃取压力、萃取温度、夹带剂乙醇的浓度、萃取时间等因素对烟碱提取率的影响,并就各个工艺参数对萃取率的影响机理和原因进行了分析与讨论。结果表明:在本研究范围内,最佳萃取工艺条件为:萃取压力30 MPa,萃取温度50℃,夹带剂乙醇浓度75%～80%,夹带剂流量为0.5 mL.min-1时,萃取时间为2～2.5 h。     

超声强化超临界流体萃取薏苡仁油和薏苡仁酯的影响因素及效果

考察了超声强化超临界流体萃取(USFE)薏苡仁中的薏苡仁油和薏苡仁酯的效果。以 CO2作为超临界流体分别研究了萃取过程中萃取温度、萃取压力、原料颗粒大小、超临界流体流量、超声参数、萃取时间等因素对萃取率的影响,并与超临界流体萃取(SFE)进行对比。结果表明,超声强化超临界流体萃取过程,最适宜的萃取温度为 40℃,比超临界流体萃取的最适宜的萃取温度降低了 5℃;最适宜的萃取压力为 20Mpa, 比超临界流体萃取的最适宜的萃取压力降低了 5Mpa;最佳萃取时间为 3.5h,比超临界流体萃取的最佳萃取时间缩短了 0.5h;萃取率提高约 10%左右。若萃取率相同时,流体流量可减少 0.5L·h-1 ,原料粒径的要求可放宽。     

超临界萃取肉桂中主要成分的研究

以超临界CO2萃取肉桂精油,研究了压力、温度、颗粒度、夹带剂（乙醇）的浓度等对提取效果的影响。结果表明,最佳工艺条件为：萃取压力为10MPa,温度为50℃,颗粒度为60目,夹带剂（乙醇）的浓度为90％。在此条件下,肉桂精油的产率为17．48％。     

四氢咔唑酮离解常数的光度法测定

研究了四氢咔唑酮在不同比例的乙醇.水混合溶剂中及不同酸度下的吸收光谱,提出了采用紫外分光光度法测定四氢咔唑酮在水中离解常数的方法.试验证明:在不同比例的乙醇.水混合溶剂中,四氢咔唑酮的离解常数与乙醇的体积分数存在良好的线性关系,通过外推至乙醇含量为零,可求得在实验条件下四氢咔唑酮在水溶液中的离解常数pKb为14.04.     

Isolation and purification of carbazole contained in anthracene slag by extraction combined with medium pressure liquid chromatography

Ultrasonic-assisted extraction (UAE) combined with medium pressure liquid chromatography (MPLC) was designed for carbazole separation from anthracene slag (AS). The effects of liquid/solid ratio, temperature, and extraction times on carbazole separation were investigated. When using CCl₄ and ethyl acetate as extraction solvents and combining with MPLC, carbazole recovery and purity are 75.1% and 95.4%, respectively. The mechanism for carbazole separation were presumed by examining intermolecular interactions such as N-H…π, π-π, and C-Cl…π interactions. These results demonstrate that UAE/MPLC has a considerable potential as a green and promising strategy for separating and purifying carbazole and other chemicals from AS.     

A COMPARISON OF DIFFERENT TECHNIQUES FOR WATER-BASED EXTRACTION OF PECTIN FROM ORANGE PEELS

The extraction of pectin from orange peels has been studied using microwave and conventional extraction, with operating conditions including different extraction periods, different solvent pHs, and different types of solvent systems. The extracted pectin from orange peels was initially precipitated with concentrated ethanol and was quantified by the carbazole assay. For microwave extraction, the greatest total amount of pectin yield was found to be 5.27% on a dry basis for 15 minutes of extraction, although the greatest amount of material per unit time (%/min) was obtained after 5 minutes. This amount was the same as that extracted using Soxhlet extraction for three hours. The 15-minute microwave extraction period was further investigated at pH values of 1.5, 2.0, 5.5, and 10.0. The greatest amount of pectin was extracted from orange peels at the most strongly acidic condition of pH 1.5. The effect of a solvent system containing ethanol and EDTA (ethylenediamine tetraacetic acid) with a 15-minute extraction period and a pH of 1.5 was studied, giving approximately double the amount of pectin extracted using distilled water.     

A COMPARISON OF DIFFERENT TECHNIQUES FOR WATER-BASED EXTRACTION OF PECTIN FROM ORANGE PEELS

The extraction of pectin from orange peels has been studied using microwave and conventional extraction, with operating conditions including different extraction periods, different solvent pHs, and different types of solvent systems. The extracted pectin from orange peels was initially precipitated with concentrated ethanol and was quantified by the carbazole assay. For microwave extraction, the greatest total amount of pectin yield was found to be 5.27% on a dry basis for 15 minutes of extraction, although the greatest amount of material per unit time (%/min) was obtained after 5 minutes. This amount was the same as that extracted using Soxhlet extraction for three hours. The 15-minute microwave extraction period was further investigated at pH values of 1.5, 2.0, 5.5, and 10.0. The greatest amount of pectin was extracted from orange peels at the most strongly acidic condition of pH 1.5. The effect of a solvent system containing ethanol and EDTA (ethylenediamine tetraacetic acid) with a 15-minute extraction period and a pH of 1.5 was studied, giving approximately double the amount of pectin extracted using distilled water.     

紫茎泽兰类黄酮提取工艺的比较与除臭测试

本实验比较了紫茎泽兰中类黄酮化合物的提取工艺,以类黄酮的得率为考察指标,考察分别以碱性水、50%乙醇溶液,95%乙醇溶液作为提取剂对类黄酮化合物得率的影响。结果表明,用50%乙醇溶液提取时提取率最高,类黄酮化合物得率达到2.743%,经嗅觉强度法测试表明,提取液具有一定的除臭效果。     

乙醇提取油茶饼残油的研究

探讨了乙醇为溶剂热回流提取油茶饼中残油的方法。通过单因素实验及正交实验考察了乙醇体积分数、液料比、浸提温度、浸提时间及提取次数对油茶饼中残油收率的影响,确定了优化的提取条件为：乙醇体积分数95%、液料比10∶1（mL∶g）、浸提温度92℃、浸提时间3h、提取次数2次。在此优化条件下,油茶饼中平均残油收率达到残油含量的96.04%。研究结果表明,乙醇具有替代6号溶剂油提取油茶饼中残油的前景。     

红旱莲总黄酮的超声波提取工艺研究

通过单因素试验和正交试验,研究乙醇浓度、料液比、超声时间、超声温度对红旱莲总黄酮提取率的影响。结果表明:影响红旱莲总黄酮提取率因素的主次关系是料液比>乙醇浓度>超声温度>超声时间,最佳工艺条件为乙醇浓度90%、料液比1∶20、超声时间35min、超声温度70℃。通过与传统醇提法相比,超声波法提取时间缩短了3/4,而总黄酮提取量提高了30%。     

草鱼鱼鳞中提取卵磷脂的最佳工艺研究

提取草鱼鱼鳞中卵磷脂,研究提取时间、乙醇浓度及料液比等对卵磷脂提取率的影响,对草鱼鱼鳞中卵磷脂的提取工艺条件进行初探。以草鱼鱼鳞为原料,乙醇溶液为萃取剂,提取卵磷脂。提取时间、乙醇浓度及料液比对卵磷脂提取率均有影响,由正交试验结果分析发现乙醇浓度是影响卵磷脂提取率的主要因素。通过正交试验,确定了提取卵磷脂的最佳工艺条件:提取温度为25℃,提取时间为1 h,料液比为1∶20(mL/g),乙醇浓度为95%。     

金莲花中总黄酮提取工艺的优化

以黄酮提取率为指标,采用正交实验的方法,对超声波辅助提取和回流提取金莲花中总黄酮的工艺条件进行了优化。结果表明,超声波提取法的优化工艺条件为:以φ(EtOH)=80%的水溶液为提取液,m(金莲花):m(提取液)=1:40,超声提取时间1h,该条件下,金莲花总黄酮提取率为6.21%(n=3);回流提取法的优化工艺条件为:以φ(EtOH)=50%的水溶液为提取液,m(金莲花):m(提取液)=1:40,提取温度60℃,提取时间3h,该条件下,金莲花总黄酮提取率为6.51%(n=3)。方差分析表明,金莲花与提取液质量比对超声波提取影响显著;乙醇体积分数对回流提取影响显著。