超临界-CO2提取苦瓜有效成分的研究(英文)

采用U11(1110)均匀设计试验优选超临界-CO2提取苦瓜总皂苷和黄酮的最佳工艺条件。分别以苦瓜中总皂苷和黄酮含量为指标探讨萃取压力、温度、萃取时间和夹带剂(无水乙醇)用量等因素在不同水平下对苦瓜皂苷和黄酮提取工艺的影响,确定苦瓜皂苷和黄酮超临界-CO2流体萃取最佳工艺参数。苦瓜皂苷的最佳萃取条件为萃取压力25.5MPa、温度42.5℃、夹带剂用量180mL;苦瓜黄酮的最佳萃取条件是压力27.5MPa、温度39.5℃、夹带剂用量226mL。萃取时间均为3h,采用一级分离,分离温度均为35℃。

超临界-CO_2法萃取苦参中苦参碱的工艺优化

目的:探讨超临界-CO2法萃取苦参中苦参碱最佳工艺。方法:采用HPLC测定含量,以萃重和苦参碱含量为考察指标,运用单因素和正交试验法优选萃取工艺。结果:选择75%的乙醇作为夹带剂,按4倍量加入,CO2流量对苦参碱萃取量有显著的影响,其次是萃取压力和萃取时间。结论:超临界-CO2法萃取苦参中苦参碱最佳工艺是萃取压力25MPa、萃取温度60℃、萃取时间3h、CO2流量40kg·h-1。

超临界-CO_2萃取酸枣仁皂苷类成分的研究

目的研究酸枣仁中皂苷类成分的超临界-CO2萃取最佳工艺参数。方法采用单因素考察法,以酸枣仁皂苷A的收率为评价指标,研究萃取压力、萃取温度、萃取时间、CO2体积流量、夹带剂类型及其用量等因素对萃取效果的影响。并与传统有机溶剂萃取法等进行比较研究。结果超临界-CO2萃取酸枣仁中皂苷类成分的最佳工艺为:萃取压力35.0 MPa,萃取温度45℃,以95%乙醇为夹带剂,其与药材投料量比例为1∶1(V/W),CO2体积流量6 L/min,循环萃取时间3.0 h。结论超临界-CO2萃取酸枣仁中皂苷类成分具有快速、高效等优点,提取效果优于传统提取方法。

类叶牡丹果实超临界提取物成分分析及其抗菌活性研究

目的:超临界提取黑龙江类叶牡丹果实中脂溶性性化学成分,GC-MS分析其组成,并对其进行抗菌活性研究。方法:应用超临界-CO2法提取类叶牡丹果实,采用气质联用(GC-MS)技术进行成分分析测定,对类叶牡丹果实超临界提取物采用微量二倍连续梯度稀释法测定最小抑菌浓度(MIC),平板转种法测定最小杀菌浓度(MBC)。结果:利用峰面积归一化法,共鉴定出了40个化学成分,相对百分含量占总离子流成分的94.24%,脂肪酸酯类占38.707%,其中甲酸异戊酯(isopentyl formate)相对含量最高,达到了22.536%,脂肪酸类化合物占36.88%,脂肪醇占8.005%,烷烃占5.51%,尚含醚、酮类、烯烃类、生物碱类和芳香族化合物。类叶牡丹果实超临界提取物对各菌株均有很好的抗菌活性。结论:类叶牡丹果实超临界-CO2提取的脂溶性成分脂肪酸酯和脂肪酸含量较高。本方法为类叶牡丹果实脂溶性成分的提取分析提供了一种选择,且提取物对4种菌株均有抑制和灭活作用。

Solubilities of Cimaterol and Mabuterol in SF-CO_2

The solubilities of two β-agonists, cimaterol and mabuterol, in supercritical carbon dioxide (SF-CO2) were measured by a recirculating method at temperatures of 40℃ and 60℃ and pressures between 9 MPa to 49 MPa.The compounds exhibit very limited solubilities in the range of 10^-5 to 10^-7 (mole fraction). Cimaterol has a higher solubility than that of mabuterol. The experimental data of solubility were correlated by four density-based models.The correlation accuracy highly depends on the system investigated, which is mainly determined by the density ranges and temperature.

A Comparative Study on Chemical Composition of Supercritical CO_2 Extraction Products in Peels of Trichosanthes kirilowii Maxim. from Changqing District

[Objective] This study aimed to investigate the differences in chemical composition of supercritical CO2 extraction products in peels of Trichosanthes kirilowii Maxim. from Changqing district. [Method] Supercritical fluidextraction （SFE） and GCMS method were applied to determine and analyze the chemical components of the extracts in peels of three strains of Trichosanthes kirilowii Maxim. [Result] The chemical components of supercritical CO2 extraction products in peels of three strains of Trichosanthes kirilowii Maxim. varied., and the number of chemical components with normalized percentage content higher than 1% was 5, 7 and 8, respectively. There are 14 kinds of common components, and the relative content of hexadecanoic acid was the highest. [Conclusion] Supercritical CO2 extracts in peels of different strains of Trichosanthes kirilowii Maxim. contain different chemical components, providing scientific basis for breeding excellent varieties and the development and utilization of Trichosanthes kirilowii Maxim.

Isolation of Organochlorine Pesticide from Ginseng with Supercritical CO_2

The feasibility of removal of the organochlorine pesticides residues of hexachlorocyclohexane(BHC) from radix ginseng with supercritical CO2 was explored. Some factors, such as extraction pressure, extraction temperature, and kinds of co-solvents were investigated. The experimental results indicate that it is possible to reduce BHC residues in radix ginseng to the level of 0.1 × 10^-6 with supercritical CO2 in the presence of suitable amount of co-solvent, such as water.

Kinetic Study on Extraction of Red Pepper Seed Oil with Supercritical CO_2

A mathematical model for extraction of red pepper seed oil with supercritical CO2was proposed.Some factors influencing the process were investigated,including operation pressure,temperature and extraction yield Xe(%).The model was solved by the method of weighted residuals and used to simulate the process numerically.The kinetic equation is expressed as Xe16.8606exp(t/9.98177)16.95457 and the simulation results are in excellent agreement with the experimental data.The optimal operating parameters are 30 MPa,318 K and 60 min.

Micronization of Griseofulvin by Ress in Supercritical CO_2 with Cosolvent Acetone

Griseofulvin (GF) is an antifungal drug whose pharmaceutical activity can be improved by reducing particle size. In this study the rapid expansion of supercritical solution (RESS) was employed to micronize GF.Carbon dioxide with cosolvent acetone was chosen as a supercritical mixed solvent. The solubility of GF in super-critical CO2 with cosolvent acetone was measured using a dynamic apparatus at pressures between 12 and 32 MPa,temperatures at 313, 323 and 333 K and cosolvent concentration at 1.5, 3.0, 4.5 and 6.0% (by mole). The effect of pre-expansion pressure, extraction temperature, spraying distance, nozzle size and concentration of cosolvent on the precipitated particles was investigated. The results show that the mean particle size of griseofulvin precipitated by RESS was less than 1.2μm. An increase in pre-expansion pressure, extraction temperature, spraying distance and concentration of cosolvent resulted in a decrease in particle size under the operating condition studied. With the decrease of nozzle diameter the particle size reduces. The crystallinity and melting point of the original material and the processed particle by RESS were tested by X-ray diffraction (XRD) and differential scanning calorimetry (DSC).No evident modification in the crystal habit was found under the experimental conditions tested. The morphology of particles precipitated was analyzed bY scanning electron microscopy (SEM).

β-Diketones at Water/Supercritical CO2 Interface： A Molecular Dynamics Simulation

The structural and dynamical properties of hexafluoroacetylacetone(HFA) and acetylacetone(AA) at the water/supercritical CO2(Sc-CO2) interface at 20 MPa and 318.15 K are investigated by molecular dynamics simulations.The TIP3P potential is used for water and the EPM2 model is for CO2.The water phase and SC-CO2 phase form a distinct immiscible liquid-liquid interface.The two chelating molecules show interfacial preference.Comparatively,the AA molecules show somewhat more preference for interfacial region,whereas the HFA molecules are preferably near the Sc-CO2 phase.The orientational distribution of the β-diketone molecules and the radial distribution functions between β-diketones and solvents are obtained in order to study the microscopic structural properties of the β-diketones at the water-SC-CO2 interface.It is found that the translational diffusion and rotational diffusion of HFA and AA are obviously anisotropic and decrease as the β-diketone molecules approach the interface.The anisotropic dynamic behavior for the solute molecules is related to the corresponding structural properties.

Shale gas exploitation with supercritical CO_2 technology

This paper analyzes the physicochemical properties of supercritical C02, the characteristic of shale gas and shale gas reservoirs. The technologies of drilling, production, fracturing using the supercritical CO2 in shale gas explo- ration are proposed, to increase the penetration rate, decrease the damage to formation while fracturing, and enhance the recovery of shale gas. It is believed that the huge economic benefits of shale gas exploration with the supercritical CO2 fluid will be obtained, and it also can initiate a new technology field of CO2 in the petroleum engineering.

Effect of Mucuna Defatted Bran Extracted with Supercritical CO2 on Soybean Seed Germination

In the present work, we investigated the effect of Mucuna deeringiana defatted bran on seed germination of soybean （Glycine max L. Merrill）. For this, the defatted bran was obtained from different operational conditions using CO2 under pressurized conditions as solvent. Oil extractions were carried out in a laboratorial scale unit at temperatures ranging from 310 to 330 K, pressure from 15 to 25 MPa and solvent flow set in 3 mL min^-1. The experiment was conducted in a germination chamber （25℃, 12：12 h light：dark photoperiod）, and the germination rate and germination speed index （GSI） were evaluated for seven days. The results showed that the oil extraction with supercritical CO2 concentrates the allelochemical L-3,4-dihydroxyphenylalanine （L-DOPA） in bran with levels from 1.86% to 4.65%. Subsequent experiments revealed that the rate of soybean seed germination was not affected by defatted bran whereas the GSI increased significantly after treatment. In brief, we concluded that the extraction process with supercritical CO2 is efficient to obtain L-DOPA of Mucuna, which influences the soybean seed germination.

Orthogonal array design for the optimization of stripping Sr(Ⅱ) from ionic liquids using supercritical CO2

The strontium ions extracted from the aqueous phase into 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide(C_2mimNTf2) with dicyclohexyl-18-crown-6(DCH18C6) was stripped effectively by supercritical CO_2(sc-CO_2).Hexafluoroacetylacetone(HFAA)-acetonitrile was found to be an excellent modifier of sc-CO_2 to enhance the stripping efficiency.In the orthogonal array design(OAD),OA_(25)(5~5)matrix was employed to optimize the stripping of Sr(Ⅱ) from the DCH 18C6-C_2mimNTf_2 system.Effects of five experimental factors:temperature,pressure,concentration of HFAA,static and dynamic extraction times as well as each factor at five-levels on the stripping of Sr(Ⅱ) were optimized.The effects of these parameters were treated by the analysis of variance(ANOVA).The results showed that Sr(II) could be nearly 100%extracted from the IL phase at 308 K,30 MPa,40 min of dynamic extraction and 60 mmol·L^(-1) HFAA in acetonitrile,respectively.Finally,the stripping mechanism was studied by ESI-MS.

Adsorption and Transfer Properties for Toluene and pDichlorobenzene in Dense CO_2/Silica Gel Packed Bed System by Moment Method and Time-Domain Analysis

Based on chromatographic theory, the moment method and the time-domain fitting analysis were applied to measure and evaluate the adsorption equilibrium constant and mass transfer properties (axial dispersion coefficient and effective intra-particle diffusivity) for toluene and p-dichlorobenzene on silica gel adsorbent in the subcritical and supercritical CO2. An apparatus based on supercritical fluid chromatography was established and the experiments were performed at temperatures of 298.15-318.15 K and pressures of 7.5-17.8 MPa. The two methods have been compared. The results show that for the systems studied here the moment method can give reasonable values for both adsorption equilibrium constant and mass transfer properties, but the time-domain analysis only can obtain the adsorption equilibrium constant. The dependence of adsorption equilibrium constant and mass transfer properties on temperature and pressure was investigated.

微管壳式换热器在能量转换循环中的应用

目前,超临界二氧化碳(S-CO_(2))布雷顿循环普遍采用印刷电路板换热器(PCHE)来保证其相对其他能量转换循环的紧凑性优势。PCHE芯体为整体结构,若内部出现泄漏或结垢等问题,很难进行维护与检修。本文提出了一种微管壳式换热器(MSTE),其结构与传统管壳式换热器类似,但其管径缩小至微通道级。由于MSTE的流道横截面积占总截面积之比较PCHE大,在典型的回热器与冷却器设计工况下,相对PCHE而言,采用MSTE可将体积与质量均减小30%以上。灵敏性分析结果显示,采用本文设计的MSTE结构的回热器与冷却器,回热器冷热流道入口温度升高20℃左右,压缩机入口温度变化均不超过1℃,说明该种结构换热器的换热能力足够支撑能量转换循环的一般工况波动。

Carotenoids Particle Formation by Supercritical Fluid Technologies

Based on the solubility in supercritical CO2,two strategies in which CO2 plays different roles are used to make quercetine and astaxanthin particles by supercritical fluid technologies.The experimental results showed that micronized quercetine particles with mean particle size of 1.0-1.5 μm can be made via solution enhanced dispersion by supercritical fluids(SEDS) process,in which CO2 worked as turbulent anti-solvent;while for astaxanthin,micronized particles with mean particle size of 0.3-0.8 μm were also made successfully by rapid expansion supercritical solution(RESS) process.

Sorption and Diffusion Behavior of Carbon Dioxide into Poly（l-lactic acid） Films at Elevated Pressures

Equilibrium sorption amount, desorption diffusion coefficients and sorption diffusion coefficients of CO2 in poly（l-lactic acid） （PLLA） films at elevated pressures were determined by the gravimetric method, in which the Fick＇s diffusion model was applied to analyze both the desorption and sorption processes. The equilibrium sorption amount of CO2 in PLLA increased with lowering temperature and elevating pressure at the temperature range from 40 to 60 ℃ and pressure from 10^4 to 2x10^4 kPa. Desorption diffusion coefficients were greatly influenced by the equilibrium sorption amount, and they were in the same order of magnitude as the sorption diffusion coefficients. The scan electron microscope （SEM） photos demonstrated that there was no foaming phenomenon of the PLLA film during desorption and sorption processes. The XRD spectra implied that the crystalline degree of PLLA film decreased after CO2 processing. It was concluded that PLLA polymer could be well swollen and plasticized by supercritical CO2.

Separation of Erucic Acid from Rape-Seed Oil Using Supercritical Carbon Dioxide with Entrainer

Separation of erucic acid from rape-seed oil using supercritical carbon dioxide with entrainer was carried on a pilot column with an inner diameter 14 mm and an effective total height 2.2 m. Experiments were focused on the effects of entrainers, i.e. acetone, ethanol and ethyl acetate, on the extraction. It is showed that entrainers made selectivity lower, but separation time shorter.

Measurement and Correlation of Solid Drugs Solubility in Supercritical Systems

A dynamic experimental set-up was utilized to measure ibuprofen solubility in supercritical CO2 at the pressure range of 8-13 MPa and the temperatures of 308, 313 and 318 K. Mole fraction values varied from 0.015＆#215;10^-3 to 3.261＆#215;10^-3 and correlated by using seven different semi empirical equations of state （Bartle, Modi-fied Bartle, Mendez-Teja, Modified Mendez-Teja, Kumar-Johnson, Sung-shim and Gordillo） as well as seven cubic equations of state （van der Waals, Redlich-Kwong, Soave-Redlich-Kwong, Peng-Robinson, Stryjek-Vera, Patel-Teja-Valderana and Pazuki）. Single and twin-parametric van der Walls mixing rules （vdW1, vdW2） were ap-plied in order to estimate the supercritical solution properties. The physicochemical properties were also obtained using Joback, Lydersen and Ambrose methods. Absolute average relatives deviation （AARD） were calculated and compared for all the correlating systems. Results showed that among the cubic equations of state （EOSs） the Pazuki equation （AARD=19.85% using vdW1 and AARD=8.79% using vdW2） and SRK equation （AARD=19.20%using vdW1 and AARD=10.03%using vdW2） predicted the ibuprofen solubility in supercritical CO2 with the least error in comparison to the others. Among the semi-empirical EOSs the most desirable deviation （AARD〈10%） was obtained by using Modified Bartle and Modified Mendez-Teja equations in all the studied temperatures.

Adsorption equilibrium of citric acid from supercritical carbon dioxide/ethanol on cyano column

Supercritical adsorption equilibrium has a significant role in defining supercritical adsorption behavior. In this paper, the adsorption equilibrium of citric acid from supercritical CO2/ethanol on a cyano column was systematically investigated with the elution by characteristic point method. Equilibrium loading was obtained at 313.15 K and 321.15 K with supercritical CO2/ethanol densities varying from 0.7068 g·cm-3to 0.8019 g·cm-3. The experimental results showed that the adsorption capacity of citric acid decreased with increasing temperature and increasing density of the supercritical CO2/ethanol mobile phase. The adsorption equilibrium data were fitted well by the Quadratic Hill isotherm model and the isotherms showed anti-Langmuir behavior. The monolayer saturation adsorption capacity of citric acid is in the range of 44.54 mg·cm-3to 64.66 mg·cm-3with an average value of 56.86 mg·cm-3.