小茴香超临界CO_2萃取产物脂肪酸成分分析

通过脂肪酸的衍生化处理，再利用色谱（GC）和色谱一质谱（GC－MS）等分析手段，对小茴香超临界CO2萃取产物的脂肪酸成分进行了剖析，共鉴定出九种脂肪酸，其中，十八碳一烯酸、十八碳二烯酸和棕榈酸是其主要成分，分别占脂肪酸总量的75．12％、15．18％和5．34％．     

八角超临界CO_2流体萃取产物化学成分的研究

本文采用GC和GC－MS技术对八角的超临界CO_2流体萃取物的化学成分进行了研究，并鉴定出34种化合物，它们的含量占出峰物质总面积的96．2％。同时与八角水蒸汽蒸馏产物的组成进行了比较。     

北苍术超临界CO2萃取产物的成分

用气相色谱－质谱－计算机联用法分析了北苍术的超临界CO2萃取产物的成分,鉴定出苍术酮、β－桉叶油醇、苍术醇31化合物,占出峰总面积的88．1％,并与传统水蒸汽蒸馏法（SD）提取的挥发油成分进行了对比。结果证明,两种方法抽提的苍术主成分基本相同,但超临界CO2萃取产物比SD产物多出现了一些重质组分,萃取更完全而有效。     

超临界CO_2萃取-分子蒸馏对白术挥发油的提取分离和GC-MS分析

用超临界CO2萃取技术提取白术挥发油，然后用分子蒸馏对所得的萃取物进行精分离，得到蒸出物；超临界萃取物收率为2．42％(w)，分子蒸馏蒸出物收率26．3％(w)；对超临界萃取物和分子蒸馏蒸出物分别进行GC—MS分析，结果超临界萃取物检测出33个化合物，分子蒸馏蒸出物检测出27个化合物，主要成分均为2，7-二甲氧基-3，6-二甲基萘、γ-芹子烯、大根香叶烯等，但相对含量有区别。     

络合剂在超临界CO_2络合萃取重金属离子中的研究进展

本文综述了络合剂在超临界CO2萃取重金属离子中的应用状况,分析并概括了不同类型络合剂在超临界CO2萃取重金属离子应用中的萃取范围、萃取效果以及优缺点,最后对络合剂的发展前景进行了展望。     

薤白挥发油成分的超临界CO2萃取及GC-MS分析

采取超临界CO2萃取和水蒸气蒸馏两种方法提取薤白中的挥发油,比较了两种提取方法得到的挥发油的理化性质,并利用GC-MS对它们进行了定性、定量分析。两种方法的主要提取物均为含硫化合物,但超临界CO2萃取法得到的含硫化合物的数量和质量都高于水蒸气蒸馏法得到的提取物。采用水蒸气蒸馏法提取8 h得到的萃取率为1.72%。通过设计的超临界CO2萃取的正交实验,得到了最佳萃取工艺条件为:压力25 MPa,温度40℃,CO2流量为25L/h。最佳萃取时间为120 min,萃取率为4.41%,是水蒸气蒸馏法萃取率的2.8倍。实验结果表明,超临界CO2萃取法简单易行,可以较快速、有效地提取薤白中的挥发油。     

白术挥发性成分的超临界流体萃取及其分析

采用超临界流体萃取白术挥发油成分,对萃取条件进行优化,并用气相色谱、气相色谱－质谱分析鉴定出超临界流体萃了的挥发油中22个化合物。最佳的超临界流体萃取条件为压力22.0MPa,温度60℃,0.5mL乙醇作改性,先静态萃取10min(CO2用量2.0mL),再动态萃取40min(CO2流速为0.3mL/min)。将超临界流体萃取与水蒸气蒸馏进行对比,水蒸气蒸馏5h的油收率仅为超临界流体萃取1h油收率的10.32%,证明超临界流体萃取替代传统萃取的必要性。     

超临界CO2萃取柚子叶挥发油的研究及GC-MS分析

采用超临界CO2萃取技术提取柚子叶的挥发性成分,以挥发油得率为衡量工艺参数的指标,通过正交试验法考察超临界CO2萃取过程中萃取温度、萃取压力、CO2的流量及萃取时间4个因素对柚子叶挥发油得率的影响。结果表明20MPa、萃取温度45℃、CO2流量7kg·h-1、萃取时间120min为最佳工艺。通过GC-MS对挥发油进行分析,从柚子叶挥发油中分离出144个组分,鉴定了61种成分,占化合物检出总量的90.4%。     

中药中重金属的去除

介绍了国内外几种常用的去除中药中重金属的方法,重点介绍了超临界CO2配合萃取去除重金属方法的配合萃取原理、配合萃取过程的影响因素、配合剂的选择、中药中重金属的存在形态与配合萃取的关系、重金属的形态分析方法等,指出目前超临界CO2配合萃取重金属存在的问题,并对今后的研究趋势进行了展望。     

栀子花挥发油超临界CO2萃取工艺优选分析

采用超临界CO2萃取法,使用正交试验设计方案,以提取率为指标,对萃取温度、萃取压力、分离压力和分离温度等影响因素进行考察。结果表明,超临界CO2萃取法萃取栀子花挥发油成分的最佳工艺条件为：萃取压力15mPa,萃取温度35℃,分离压力15mPa,分离温度25℃。该方法简便、可靠、选择性高,适于工业化生产。     

Supercritical extraction of thyme (Thymus vulgaris L.)

Summary Chromatographic methods for the qualitative and quantitative analysis of thyme (Thymus vulgaris L.) extracts (essential oil obtained by steam distillation and extracts obtained by carbon dioxide supercritical fluid extraction and methylene chloride) are described. The composition of extracts obtained at different pressures (from 80 bar to 400 bar) and constant temperature (40°C) is discussed. The extraction system thyme— supercritical carbon dioxide was modelled by empirical equations defining the dependence of the total extract (TE) solubility and thymol solubility in CO₂ on the density of carbon dioxide.     

溶剂抽提、水蒸气蒸馏和超临界萃取用于古蓬香脂组成分析方法的比较(英文)

采用乙醇和丙酮溶剂抽提、ＣＯ２超临界萃取（ＳＦＥ）以及水蒸气蒸馏（ＳＤ）的方法提取古蓬香脂乳胶。对乙醇和丙酮提取物进行了ＨＰＬＣ和ＧＣ－ＭＳ分析。两个提取物的ＨＰＬＣ谱图十分相似,总共可分离出１７个组分。而乙醇提取物的ＧＣ－ＭＳ分析鉴定表明有２１个组分。ＳＦＥ提取物的ＧＣ－ＭＳ分析得到８个组分。ＳＤ提取物有１４个组分。在超临界流体中加入甲醇无论对提取物的组分数还是对其浓度都没有什么影响。     

Supercritical fluid extraction of oxindole alkaloids from Uncaria tormentosa

Supercritical fluid extraction of oxindole alkaloids from Uncaria Tormentosa is described. The extraction was performed with supercritical carbon dioxide alone and with supercritical carbon dioxide modified with 10% metanol, and the extracts were analyzed by GC/MS and HPLC/MS.     

Supercritical fluid extraction of kava lactones from Piper methysticum (kava) herb

Supercritical fluid extraction of kava lactones from Piper methysticum Forst. herb is described here. The extraction was performed with supercritical carbon dioxide alone and supercritical carbon dioxide modified with 15% ethanol, and the extracts were analyzed by gas chromatography/mass spectrometry. Seven lactones including: 7,8-dihydrokavain; kavain; 5,6-dehydrokavain; 5, 6, 7, 8-tetrahydroyangonin; dihydromethysticin; yangonin; and methysticin were the major constituents in the SFE extract.     

黄荆子挥发性成分的分析

分别采用水蒸汽蒸馏法和超临界流体CO2萃取法提取黄荆子中的挥发性成分.利用气相色谱-质谱(GC/MS)联用技术对其化学成分进行了分析鉴定,并通过面积归一法测定了各成分的相对含量.对两种提取方法的结果进行了比较.结果表明,子午岭的黄荆子中含有多种药用成分,而超临界流体CO2萃取法更能有效地提取黄荆子中的有效成分.     

Preparative supercritical fluid extraction of pyrethrin I and II from pyrethrum flower

A preparative supercritical fluid extraction system is described and was used with supercritical carbon dioxide to extract the active insecticide components pyrethrin I (PI) and pyrethrin II (PII) successfully from pyrethrum flower. A high-performance liquid chromatography method was developed and was used to separate and analyze the supercritical carbon dioxide extracts. Extraction efficiencies under several different extraction conditions were examined. Under the conditions examined, the most effective extractions of PI and PII (140 +/- 18 mg and 55 +/- 9 mg per 100 g of dry pyrethrum flower powder) were performed at 40 degrees C and 1200 psi. The results showed that extraction efficiencies of supercritical carbon dioxide are much better than those of n-hexane for pyrethrins I and II. During the extraction process, the most efficient extraction period was the first 3 h of the experiment.     

分子动力学模拟苯和萘在超临界二氧化碳中的无限稀释扩散系数

采用球型模型和点位-点位模型对超临界二氧化碳的自扩散系数及苯或萘在超临界二氧化碳中的无限稀释扩散系数进行了分子动力学模拟。结果表明,球型模型及点位-点位模型均可较准确地预测二氧化碳的自扩散系数,球型模型因形式简单,准确度相对较差;点位-点位模型准确度虽高,但需较长的模拟机时。两种位能模型所获得的准确度相当,但点位-点位模型可以更精细地反映体系的微观结构。     

Siloxane/silane‐crosslinked systems from supercritical carbon dioxide: II. Pendant phenyl poly(carbosilane/siloxane)s

New silicone‐containing polymers with crosslinkable units have been synthesized by hydrosilation polymerization in both toluene and supercritical carbon dioxide (70°C, 3000 psi) catalyzed by platinum‐divinyltetramethyldisiloxane (Pt‐DVTMS). It was found that high molecular polymers were obtained in both toluene and supercritical carbon dioxide. The polymers were characterized by FTIR, NMR, GPC, TGA, and DSC. The molecular weights of these polymers ranged from 9000 to 39,000. With further hydrolysis and thermal curing, the molecular weight can be increased significantly. Comparison of the properties between reactions in toluene versus supercritical carbon dioxide indicated that the green solvent is a usable alternative for hydrosilation polymerization. The new polymers synthesized in either toluene or supercritical carbon dioxide are thermally stable, ranged from 350 to 488°C. Copyright © 2008 John Wiley & Sons, Ltd.     

Orthogonal array design for the optimization of supercritical fluid extraction of baicalin from roots of Scutellaria baicalensis Georgi

Supercritical fluid was used to extract baicalin from the roots of Scutellaria baicalensis Georgi. An orthogonal array design (OAD), OA(9)(3(4)), was employed as a chemometric method for the optimization of the supercritical fluid extraction of baicalin from the herbal medicine. Four parameters, namely, modifiers, temperature and pressure of supercritical fluid, and the dynamic extraction time, were studied and optimized by a three-level OAD in which the interactions between the parameters were neglected. Determinations of the extracts were performed by high-performance liquid chromatography. The effects of parameters were studied using analysis of variance. The results showed that selection of the modifier was the main factor in attaining higher yields of baicalin. While the other three factors had some effect on the extraction of the compound, the effect was much less than that of the modifiers. 1,2-Propanediol-modified supercritical fluid was more effective than 95% ethanol-modified supercritical carbon dioxide or methanol-modified supercritical carbon dioxide for the extraction of baicalin from the solid matrix. Finally, experimental conditions were proposed which can provide the highest extraction yield with respect to the considered factors.