• KSBB Journal
• /
• v.17 no.2
• /
• pp.148-152
• /
• 2002

The extraction of volatile essential oil using supercritical carbon dioxide with 2%(v/v) ethanol and non-ethanol was performed in a semi-continuous flow extractor at the range of pressures and temperatures 6.9 to 17.2 MPa and 30 to 45$^{\circ}C$, respectively. When ethanol was added to the co-solvent, the solubility of volatile essential oils was increased up to 90% over the neat CO$_2$ value. The most efficiency of extraction of the voilatile essential oils was achieved at 13.8㎫ and 40$^{\circ}C$ by supercritical carbon dioxide with entrainer from Citrus junos peel.

• Polymer(Korea)
• /
• v.32 no.1
• /
• pp.13-18
• /
• 2008

For the evaluation of brominated flame retardants included in polymeric electronic devices, we investigated the extraction methods and solvent systems for four different types of polymers of PC (polycarbonate), PP (polyropylene), PET (poly(ethylene terephthalate)) and PBT (poly(butylene terephthalate)) using different solvent systems of hexane/acetone, THF, toluene, and THF/toluene. In order to compare the extraction efficiency of different methods and solvent systems, the deca-BDE (decabromo diphenyl ether) flame retardant was included in PC, PP, PET and PBT systems and subsequently extracted by soxhlet, ultrasonic, accelerated solvent, microwave and supercritical fluid extraction methods. The amount of the extracted flame retardant was monitored to evaluate the extraction efficiency. The ultrasonic extraction method was found not to be acceptable as an extraction method for the polymer systems mainly due to a low salvation efficiency of the organic solvents. Soxhlet, accelerated solvent and microwave extraction methods exhibited over 80% of extraction efficiency for toluene. The supercritical fluid extraction method, which has been used as an extraction method for flame retardants in polymers, showed the extraction efficiencies of ca. 100% for PC and PP in the optimal extraction conditions of $60^{\circ}C$ and 120 bar.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.2
• /
• pp.379-383
• /
• 2013

For the production of ethanol from freshwater cyanobacteria, a new pretreatment method using supercritical fluid was introduced. In this study, it was found that the supercritical fluid could penetrate inside the cell wall and help to liberate starch from cyanobacterial cells which resulted in the increase of the efficiency of ethanol production. For Microcystis aeruginosa, supercritical fluid pretreatment increased the amount of ethanol produced from cyanobacteria from 1.53 g/L to 2.66 g/L. For Anabaena variabilis, the amount of ethanol was increased from 1.25 g/L to 2.28 g/L. With use of supercritical fluid pretreatment, the efficiency of the process to obtain higher ethanol yields from freshwater cyanobacteria was improved upto 80%. The optimum temperature and pressure conditions for supercritical fluid pretreatment were determined as the temperature of $40^{\circ}C$ and the pressure of 120 atm. This study demonstrates the feasibility of using supercritical fluid pretreatment for ethanol production using freshwater cyanobacteria.

• The Journal of the Convergence on Culture Technology
• /
• v.8 no.6
• /
• pp.605-614
• /
• 2022

In this study, oregano was extracted by supercritical extraction and hydrothermal extraction method. In vitro experiments such as antimicrobial and antioxidant activity test were performed. As a result of the disc diffusion method, only the supercritical extracts formed a clear zone. The MIC for S. aureus was found only in the supercritical fluid extracts and it was 1000 ㎍/mL. The hydrothermal extract's MIC is 125 ㎍/mL for C. acnes. Through biofilm inhibition assay, we found that the supercritical fluid oregano extracts inhibit the biofilm of S. aureus by more than 70% even at low concentrations of 125 ㎍/mL. On the other hand, the antioxidant ability of the hydrothermal extract was better than that of the supercritical fluid extracts. Furthermore, we tried to make a skincare ingredient for atopic dermatitis by utilizing the S. aureus biofilm inhibitory ability of oregano supercritical fluid extracts. Liposome was used to overcome the low solubility of the oregano supercritical fluid extracts and increase stability.

• Korean Journal of Food Science and Technology
• /
• v.25 no.3
• /
• pp.288-294
• /
• 1993

Solubilities of urea-crystallized tuna oil methyl esters in supercritical carbon dioxide were determined by a flow through extraction reactor. Experimental results obtained under a quasi-equlibrium condition showed that at 150 bar, solubilities of the esters in supercritical $CO_2$ were 0.075, 0.028 and 0.006(w/w) at $40^{\circ}C,\;60^{\circ}C\;and\;80^{\circ}C$, respectively. In the pressure and temperature ranges $(100{\sim}200bar\;and\;40{\sim}80^{\circ}C)$, the solubility increased with the density of $CO_2$. However, selectivity of supercritical carbon dioxide on the extracted compounds was much better at low density than at high density. Supercritical fractionation with a temperature gradient $(50{\sim}75^{\circ}C)$ resulted in concentrates of EPA and DHA in purities of 12% and 85%, respectively.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.46 no.6
• /
• pp.56-62
• /
• 2014

This study aims to investigate the applicability of supercritical fluid extraction as a dewaxing technique to restore the beeswax-treated volume of the Annals of the Joseon Dynasty in various deterioration and damage conditions. Thus, this study analyzed the dewaxing efficiency and changes in physical and morphological properties before and after dewaxing, by applying the optimal supercritical fluid extraction dewaxing condition ($70^{\circ}C$, 40 MPa, $CO_2$, Co-solvent 20% DCM, 2 hour) to 3 kinds of beeswax-treated paper with different deterioration rates (dry artificial aging of 10, 20 and 30 days at $120^{\circ}C$). After dry artificial aging at $120^{\circ}C$ for 30 days, the average molecular weight of the beeswax-treated specimen was $1.856{\times}10^5g/mol$, showing deterioration about 80% of the beeswax-treated paper before dewaxing. It was a similar level to the molecular weight of the bees-waxed volume of the Annals of the Joseon Dynasty that has a higher degree of damage. As a result of analyzing the dewaxing efficiency through FT-IR analysis, this study discovered that it was possible to effectively dewax beeswax-treated paper in the range of deterioration 20 to 80% with this supercritical fluid extraction dewaxing technique applied. As a result of analyzing changes in the physical and morphological properties before and after dewaxing, the viscosity tended to decrease to a slight degree, and since no morphological deformation or damage of stencil fibers was found, it was concluded possible to conduct stable dewaxing through this supercritical fluid extraction technique.

• Journal of the Korean Chemical Society
• /
• v.47 no.6
• /
• pp.578-584
• /
• 2003

Polychlorinated biphenyls (PCBs) known as environmental contaminants in soil were analyzed by the soil pollution standard process test and the static supercritical $CO_2$ extraction mode. It was shown that the percent average recoveries of PCBs by the soil pollution standard process test were ranged in 25-35% and the corresponding standard deviations were above 10%. In contrast, the percent average recoveries of PCBs by the static supercritical $CO_2$ extraction mode were 2-2.5 times higher and standard deviations were within 7%. These results indicate that static supercritical $CO_2$ extraction mode may be a useful alternative to sample pretreatment certified by the soil pollution standard process test. The increasing supercritical $CO_2$ pressure from 1130 psi to 1996 psi at $40^{\circ}C$ enhanced the recovery of all PCB congeners from soil. However, at same Tc and Pc, the equilibrium time (5 versus 60 minutes) had no effect on the recovery of each PCB congener. Finally, similar PCB recoveries were obtained under the same extraction condition, regardless of the molecular weight and structure (coplanar versus non-coplanar) of PCB congeners.

• Korean Journal of Pharmacognosy
• /
• v.30 no.1
• /
• pp.59-64
• /
• 1999

Supercritical fluid extraction (SFE) technique was applied to extract cytotoxic substances from five medicinal plants including Angelica gigas, Angelica acutiloba, Aralia cordata, Spirodela polyrhiza, Bupleurum falcatum, and Acanthopanax sessiliflorus. The cytotoxicities against P388, A549, and HL-60 cell lines were determined for the supercritical carbon dioxide extracts of five plant materials employed and were compared with those of the conventional organic solvent extracts such as n-hexane, $CHCl_{3}$, and MeOH to evaluate the SFE as an alternative method to conventional organic solvent extraction. In most cases, the SFE extracts of plant materials showed enhanced cytotoxicities when compared with those of other organic solvent extracts. In addition, the optimum temperature and pressure of SFE for extraction of the cytotoxic substances were largely affected by both the plant species and the cell lines tested. These results suggested that SFE could be an alternative to the conventional organic solvent method for the selective extraction of cytotoxic compounds from plants.

• Journal of Food Hygiene and Safety
• /
• v.27 no.2
• /
• pp.109-116
• /
• 2012

The study indicated that antimicrobial activity about gram positive and gram negative bacteria of ginger-oleoresin(GO) extract with the condition of ethanol and supercritical fluid extractions. As the concentration of extraction increases, the clear zone of GO ethanol extract also increased dependently. This led the antimicrobial activity of gram positive bacteria to take bigger place than gram negative bacteria especially in Listeria monocytogenes. There was a high antimicrobial activity in E-III treatment where the ratio of the ginger powder extract to ethanol extraction was 1:6. It was quite effective to treat the antimicrobial activity of GO ethanol extract under $80^{\circ}C$ and there was not big difference in the intervals which were the extraction time - 1 to 7 hours. The antimicrobial activity of supercritical fluid extract seemed to take the biggest place in Listeria monocytogenes. From the supercritical fluid extract, it was shown the strong ability of antimicrobial activity in the condition with 100 bar $35^{\circ}C$, 250 bar $35^{\circ}C$ and 250 bar $65^{\circ}C$. Furthermore, according to the case of solvent extract, there was not any significant difference in the antimicrobial activity with condition of extraction. However, there was significant antimicrobial activity in E-III treatment of 100 bar and 500 bar of extraction pressure, and $35^{\circ}C$ and $65^{\circ}C$ of extraction temperature.

• Food Engineering Progress
• /
• v.15 no.3
• /
• pp.203-208
• /
• 2011

Effects of particle size and high pressure processing on the extraction rate of oil compounds from soybean powder were evaluated by Soxhlet method using hexane and supercritical fluid extraction (SFE) using $CO_{2}$. SFE was carried out at 4,000 psi and $50^{\circ}C$ for 4 hr. The mean particle sizes were varied from 26.7 to 862.0 ${\mu}m$ by controlling milling time. Saturation solubility increased as the particle size decreased. At large particle size, high pressure processing (HPP) showed higher extraction yield in both hexane extraction and SFE, but, as the particle size decreased, the HPP was irrelevant to the extraction yield in SFE. The higher extraction rate obtained from the smaller particle size. The scanning electronic microscopy of soybean powder treated by HPP showed pores on the surface of the particle. The higher extraction rate and yield from HPP treatment might be due to the less internal resistance of transferring the solvent and miscellar in the solid matrix by collapsing of tissues.