超临界二氧化碳萃取秋水仙碱（英文）

利用超临界二氧化碳对秋水仙块根（经粉碎）中的秋水仙碱进行了萃取,采用高效液相色谱法对萃取出的秋水仙碱的质量分数进行了测定。实验选择40℃20～40MPa作为超临界苹取的操作条件,采用体积分数为95％的乙醇在索氏提取器中对样品进行了对比苹取实验。结果表明:不加浸泡剂进行浸泡处理的样品中的秋水仙碱很难被超临界二氧化碳萃取,在40℃,35MPa条件下,消耗1．28mol的二氧化碳只得到3％的萃取率。加入极少量的有机溶剂浸泡处理样品15min后再进行超临界萃取,可以极大程度地提高秋水仙碱的萃取率。在所选的浸泡剂乙醚、丙酮、乙腈、甲醇、乙醇中,乙醇浸泡效果最佳,经浸泡后,在40℃,35MPa条件下进行超临界二氧化碳萃取,仅消耗0．21mol的二氧化碳,一次苹取的秋水仙碱萃取率就达80％。秋水仙碱的质量分数从原植物样品中的0．18％提高到萃取物中的6．92％,提高了近38倍,而有机溶剂乙醇提取只能达到0．98％,仅提高了5倍。超临界苹取后的样品经简单的过滤即可进样进行HPLC分析,有机溶剂乙醇提取则需要氯仿苹取、溶剂回收等样品制备过程。HPLC分离测定秋水仙碱采用苯基柱,甲醇-水梯度洗脱,流速0．5mL／min,UV检测λ=353um,经选择,其最佳条件为：从V（甲醇）：V（水）=50：50开始,15min内到V     

超临界CO2萃取异甘草素的提取工艺

采用正交试验与单因素试验相结合方法对异甘草素的超临界CO2提取工艺进行了研究,并与常规索氏提取法的实验结果进行了对比。得到的最佳工艺参数为:萃取压力30 MPa、萃取温度45℃、夹带剂85％乙醇、液固比为5:1、CO2流量10 kg／h、分离压力5．5 MPa、分离温度35℃。实验结果表明,在优化的条件下,超临界CO2萃取异甘草素的提取率为0．035％,异甘草素在提取物中的质量分数为0．84％,分别是索氏提取法提取率的3．5倍,质量分数的3．0倍。超临界CO2萃取异甘草素所用时间短、溶剂用量少、提取效率高、环境友好,是一种高效、快速提取异甘草素的方法。     

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。     

中国桦甸油页岩超临界萃取研究

对桦甸北台子油页岩样品,用甲苯、甲苯四氢萘混合溶剂进行丁非等温(升温速率为8 K·min~(-1))的超临界萃取实验(萃取压力为10MPa,终温为550℃)。为选择高转化率和油类产物高产率的萃取条件,进行了样品粒度(1.2—2.5mm)、溶剂流率(2dm~3·h~(-1))以及甲苯中供氢组分含量(分别为10%、20%、30%)的系统实验。甲苯溶剂超临界萃取油类产物产率是一般干馏方法的2倍。在溶剂甲苯中加入少量供氢组分后,油母转化完全,油类产物产率高。超临界萃取可用一级反应描述,文中用积分法求解了动力学参数。     

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。     

苹果中5种氨基甲酸酯类农药的超临界流体萃取及其气相色谱法测定

提出了一种采用超临界流体萃取技术对苹果中５种氨基甲酸酯类农药进行萃取及用气相色谱检测的方法。实验以二氧化碳作为超临界流体，加入３％的甲醇作为改性剂，对３种惰性载体和加入硅藻土的苹果基体的超临界萃取条件进行了选择，以气相色谱配以氮磷检测器检测５种氨基甲酸酯类农药，取得了满意的结果，回收率为８８％～９８％。     

苹果中5种氨基甲酸酯类农药的超临界流体萃取及其气相色谱法测定

 提出了一种采用超临界流体萃取技术对苹果中５种氨基甲酸酯类农药进行萃取及用气相色谱检测的方法。实验以二氧化碳作为超临界流体，加入３％的甲醇作为改性剂，对３种惰性载体和加入硅藻土的苹果基体的超临界萃取条件进行了选择，以气相色谱配以氮磷检测器检测５种氨基甲酸酯类农药，取得了满意的结果，回收率为８８％～９８％。     

超临界流体萃取和高效液相色谱法测定银杏酸

介绍了一种用改性的超临界二氧化碳萃取和离线的反相高效液相色谱分析银杏叶提取物中银杏酸含量的方法。对萃取条件进行了优化,结果表明以硅胶为载体,在３０ＭＰａ、５５℃条件下,８％甲醇作改性剂时的超临界二氧化碳对银杏酸有最理想的回收率和选择性。最小检测限为０．４２ｍｇ／Ｌ。     

超临界CO_2萃取桑叶总黄酮工艺的研究

采用超临界CO2萃取桑叶总黄酮,以得率为指标,对萃取压力、萃取温度、夹带剂乙醇的浓度和流量等影响因素进行正交试验。结果表明最佳工艺条件为:萃取压力35 MPa,温度55℃,乙醇质量分数90%,乙醇流量0.01 mL/min。此条件下桑叶总黄酮得率2.28%。该方法简便、可靠、选择性高,适于工业化生产。     

采用超临界CO_2萃取技术提取废次烟叶中的茄尼醇

采用超临界CO2萃取技术提取废次烟叶中的有效成分茄尼醇,以乙醇为夹带剂,研究了萃取压力、萃取温度、CO2的流量、萃取时间、夹带剂的使用、分离温度和原料粒度等方面对萃取效果的影响,并对其中影响较为显著的因素进行了正交试验,通过极差和方差分析确定了萃取体系适宜的工艺条件。萃取压力为20 MPa,萃取温度为45℃,CO2的流量为15 L/h,萃取时间为2 h,夹带剂为95%的乙醇,分离温度为40℃,原料粒度为40~60目。     

蔬菜中有机氯农药残留的超临界流体提取和气相色谱法测定

 建立了用超临界流体萃取、气相色谱测定韭菜中百菌清、艾氏剂、狄氏剂、异狄氏剂残留量的方法。样品与无水硫酸镁混合后进行萃取。用正交设计法选择萃取条件，最佳条件为压力３０．４ＭＰａ，温度４０℃。静态萃取时间１ｍｉｎ，ＣＯ２用量１５ｍＬ，收集液为乙酸乙酯。     

Supercritical fluid clean-up of environmental samples for the analysis of polycyclic aromatic hydrocarbons using time-of-flight secondary ion mass spectrometry.

A novel sample-pretreatment method for time-of-flight secondary ion mass spectrometry (TOF-SIMS) was developed using supercritical fluid extraction (SFE). In SFE, the extraction efficiency of a certain organic matter is controlled by the pressure and temperature of supercritical CO2. Two-step SFE (1st step at 10 Mpa, 40 degrees C; 2nd step at 30 MPa, 120 degrees C) was applied to diesel exhaust particles containing many kinds of n-alkanes and aromatic species. n-Alkanes and polycyclic aromatic hydrocarbons (PAHs) were extracted in the 1st and 2nd steps, respectively. This selectivity was utilized for the sample preparation of TOF-SIMS analysis. Diesel exhaust particles after the 1st step of extraction were analyzed with TOF-SIMS, aiming at PAHs as analytical targets. The obtained spectrum was simplified, and mass peaks of individual PAHs were easily assigned, because unwanted compounds, like n-alkanes, were selectively removed by SFE. Furthermore, a simple calculation elucidated the outline of the spectrum.     

Supercritical fluid extraction of cynaropicrin and 20-hydroxyecdysone from Leuzea carthamoides DC

Leuzea carthamoides is an adaptogenic plant containing biologically active compounds as ecdysteroids and guaianolide-type sesquiterpene lactones, conventionally extracted from the plant with ethanol. It may be a potential source of the mentioned natural compounds. Ethanol-modified near-critical CO(2) was used as selective solvent with the aim to increase the level of 20-hydroxyecdysone in the extract from L. carthamoides roots and to remove selectively cynaropicrin, a sesquiterpene lactone of bitter taste, from the leaves. The extraction conditions were varied (pressure 20-28 MPa, temperature 40-60 degrees C, ethanol concentration in the solvent 0-7.1%) and the extraction yield and extract composition were compared with the results of ethanolic extraction. The supercritical fluid extraction (SFE) from finely powdered plant was controlled by phase equilibrium. Cynaropicrin was quantitatively removed from the leaves where 89% of 20-hydroxyecdysone was retained. The extraction yield of 20-hydroxyecdysone from roots with ethanol-modified CO(2 )was lower by 30% than with ethanol but its concentration in the extract was higher by 67%.     

离线超临界流体萃取和气相色谱-红外-质谱联用测定水中有机污染物

 利用吸附剂ＧＤＸ－３０１对黄河水中的有机污染物富集并以超临界ＣＯ２脱附后，通过气相色谱、色谱－红外－质谱联用技术对各目标分析物逐一定性，并比较了超临界ＣＯ２萃取和溶剂洗脱的结果。实验表明，在２０ＭＰａ，６０℃，４０ｍｉｎ条件下进行超临界ＣＯ２萃取时的萃取效率和溶剂萃取效率相当或略高。     

Supercritical fluid extraction of grape seed oil and subsequent separation of free fatty acids by high-speed counter-current chromatography

Supercritical fluid extraction (SFE) of grape seed oil was performed to study the effect of various parameters such as pressure, temperature and the particle size of the sample on the yield and composition of oil using an analytical-scale SFE system. Then the extraction was scaled up by 125 times using a preparative SFE system under the optimized conditions of high pressure (30-40 MPa) and low temperature (35-40 degrees C) with medium particle size (20-40 mesh). The maximum yield of the oil can reach 6.2% with pure supercritical CO2 and 4.0% more oil can be obtained by adding 10% of ethanol as modifier. The unsaturated fatty acids (UFSs) make up about 70% in the oil on the basis of free fatty acids. The grape seed oil was then subjected to separation and purification for free fatty acids after saponification by high-speed counter-current chromatography coupled with evaporative light scattering detection (ELSD). The separation of 1.0 g of oil can yield about 430 mg pure linoleic acid at 99% purity. The fatty acids were analyzed by HPLC-ELSD.     

Supercritical fluid extraction of catechins from Cratoxylum prunifolium dyer and subsequent purification by high-speed counter-current chromatography

Supercritical fluid extraction of tea catechins including epigallocatechin-3-O-gallate (EGCG) and epicatechin-3-O-gallate (ECG) from Cratoxylum prunifolium Dyer was performed. The optimization of parameters was carried out using an analytical-scale supercritical fluid extraction (SFE) system designed in our laboratory. Then the extraction was scaled up by 100 times using a preparative SFE system under a set of optimized conditions of 40 degrees C, 25 MPa and modified CO2 with 80% ethanol aqueous solution. The combined yield of EGCG and ECG reached about 1 mg per 1 g of tea leaves where the solubility was near 1.4 x 10(-4) mass fraction of CO2 fluid. EGCG and ECG of high purity (>98%) were obtained from the crude preparative extract by high-speed counter-current chromatography.     

Carotenoids extraction from Japanese persimmon (Hachiya-kaki) peels by supercritical CO(2) with ethanol.

The extraction of carotenoids from Japanese persimmon peels by supercritical fluid extraction (SFE), of which the solvent was CO(2), was performed. In order to enhance the yield and selectivity of the extraction, some portion of ethanol (5 - 20 mol%) was added as an entrainer. The extraction temperature ranged from 313 to 353 K and the pressure was 30 MPa. The effect of temperature on the extraction yield of carotenoids was investigated at 10 mol% of the ethanol concentration in the extraction solvent, and a suitable temperature was found to be 333 K among the temperatures studied with respect to the carotenoid yield. With increasing the entrainer amount from 0 to 10 mol% at a constant temperature (333 K), the carotenoid yield in the extraction was improved, whereas the selectivity of the extracted carotenoids was drastically depressed. We also conducted qualitative and quantitative analyses for the carotenoid components in the extract by HPLC, and analyzed the extraction behavior of each individual carotenoid (alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, lutein, and zeaxanthin). The selectivity of each carotenoid changed with the elapsed time and its time evolution was dependent on the carotenoid component, indicating that the location profile and the content can be important factors to understand the SFE behavior of each carotenoid in persimmon peels.     

超临界流体萃取法对有机锡化合物的选择性萃取

 研究了用超临界流体萃取法直接从脂肪基质的固体样品（大豆粉）中选择性地萃取有机锡化合物的方法。模拟试样萃取结果表明：用较低压力和较高温度的超临界态ＣＯ２作流动相时，有机锡达到最大萃取率，而脂肪类物质仅被少量萃取，从而消除了脂肪类物质对超临界流体色谱法测定有机锡的干扰。     

An efficient new method for extraction, separation and purification of psoralen and isopsoralen from Fructus Psoraleae by supercritical fluid extraction and high-speed counter-current chromatography

Psoralen and isopsoralen were extracted from Fructus Psoraleae (Psoralea corylitolia L.) by supercritical CO2. The effect of various parameters, i.e., pressure, temperature and sample particle size on yield was investigated with an analytical-scale supercritical fluid extraction (SFE) system to find the optimal conditions. The process was then scaled up by 50 times with a preparative SFE system under the optimized conditions of pressure (26 MPa), temperature (60 degrees C) and a sample particle size of 40-60 mesh. The yield of the preparative SFE was 9.1% and the combined yield of psoralen and isopsoralen was 2.5 mg/g of dry seeds. Psoralen and isopsoralen in the extract were separated and purified by high-speed counter-current chromatography with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (1:0.7:1:0.8, v/v), and the fractions were analyzed by HPLC, MS, 1HNMR and 13C NMR. The structures of the products were further confirmed by comparison with authentic samples (National Institute of the Control of Pharmaceutical and Biological Products, Beijing, China).     

Optimization of the extraction and fractionation of corn bran oil using analytical supercritical fluid instrumentation

Supercritical fluid extraction (SFE) is combined with supercritical fluid chromatography (SFC) in an analytical mode to develop a system for fractionating and enriching high value ferulate-phytosterol esters (FPE) contained in corn bran oil. Corn bran is initially extracted with neat supercritical carbon dioxide (SC-CO2) at various pressures (13.8, 34.5, and 69 MPa) and temperatures (40, 60, and 80 degrees C) to see if the FPE can be enriched in the extracts. These initial studies show the greatest percentage of FPE could be extracted under two sets of conditions: 69 MPa at 80 degrees C and 34.5 MPa at 40 degrees C. Both sets of parameters yield an extract containing approximately 1.25% FPE. A stock supply of corn bran oil is then produced by scaled-up SFE at 34.5 MPa and 40 degrees C for subsequent chromatographic fractionation. The SFE-obtained corn bran oil is then applied to the head of a minichromatographic column containing an amino-propyl sorbent. SFC is than commenced using neat SC-CO2 at 69 MPa and 80 degrees C to remove the majority of the triglyceride-based oil. Pressure and temperature are then lowered to 34.5 MPa and 40 degrees C, respectively, and ethanol is added as a modifier. The modifier is added in an increasing stepwise gradient program, and fractions are collected at equal volume intervals. The resultant fractions are analyzed by analytical high-performance liquid chromatography with evaporative light-scattering detection and show that FPE could be enriched to a 14.5% (w) level.