• Journal of Korean Society of Environmental Engineers
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• v.35 no.1
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• pp.70-73
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• 2013

Solubility of oil contaminants in surfactant solutions plays an important role in selecting a suitable surfactant type for soil remediation. Solubility measurement procedures consist of making an equilibrium between surfactant solution and oil, solvent extraction using dichloromethane, and condensation for gas chromatography analysis. Solubility measurement requires time consumption and lots of materials. Interfacial tension is the contracting force between two immiscible liquids, surfactant solution and oil, and also closely related to solubility of oil. This study established a relationship between the interfacial tension and solubility of diesel fuel in surfactant solution and suggested a quick method to estimate solubility of oil in a surfactant solution by measuring its interfacial tension. The results of this study showed that the solubility of diesel fuel in surfactant solution was exponentially increased by decreasing the interfacial tension between two immiscible liquids. The solubility of diesel fuel was significantly increased under the interfacial tension conditions below 1 dyne/cm, while the solubility change was not apparent under the interfacial tension conditions beyond 5 dyne/cm. Interfacial tension measurements may allow us to quickly select an efficient surfactant and its concentration for soil remediation.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.677-682
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• 1993

Hexane(Hx), ethyl acetate(EtoAc) methanol(MeOH) and 99% ethanol(EtOH) extract of Rhus javanicus Lines with synergists e.g. ascorbic acid(AA), citric acid(CA) and ${\delta}-tocopherol$(TO) were tested their antioxidative effect on palm oil and lard by Rancimat. The methanol showed the highest extraction yield as 14.53%(w/w). When each 600 ppm of Hx, EtOAc, MeOH and EtOH extract with 200 ppm of AA was added to palm oil, the antioxidative index(AI: induction time of oil containing of each extract/induction time of test oil) were 1.83, 2.25, 2.81 and 2.85 respectively which were higher than other treatments and 600 ppm of each extract with 200 ppm of TO to lard, the AI were 3.64, 7.83, 7.34 and 9.30 respectively. Each solvent fractionate of EtOH and EtOAc extracts resulted no higher antioxidative effect than crude whole extract. Palm oil and lard containing 600 ppm of methanol extract were very stable comparing with the control by POV and TBA at oven test($60^{\circ}C$).

• Analytical Science and Technology
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• v.23 no.6
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• pp.544-550
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• 2010

Mistaking pink colored thermal oil for grape wine, a victim drank the oil to death which was analyzed to contain 39% of ethylene glycol. Thermal oil could be used for heat transfer to prevent the malfunction due to the high pressure in the boiler operated at high temperature when using water. Main component of thermal oil is known to be mineral oil or ethylene glycol. From the blood and other tissue of the victim from autopsy, ethylene glycol and its metabolite were simultaneously analyzed by GC/MS after extraction under acidic condition with acetonitrile followed by derivatization with BSTFA. About 0.2 g of the specimens were pretreated with 50 uL of 0.5 M HCl solution to keep acidic condition, then dehydrated with anhydrous sodium sulfate followed by concentration under nitrogen stream. Ethylene glycol and glycolic acid concentration in blood was measured to be $2,755\;{\mu}g/mL$ and $174\;{\mu}g/mL$ respectively. In other specimen, the concentration of ethylene glycol and glycolic acid was $860\;{\mu}g/g\sim1,290\;{\mu}g/g$ and $93\;{\mu}g/g\sim134\;{\mu}g/g$. Especially, crystal appeared in kidney which was supposed xalate from the metabolite of ethylene glycol.

• Korean journal of food and cookery science
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• v.24 no.4
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• pp.452-459
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• 2008

The purpose of this study was to investigate the antioxidative effects of Sea tangle powder(STP) solvent extracts as well as Maejakgwa made with STP. The STP solvent extracts were added to soybean oil at a quantity of 0.05%. The solvents used for extraction were methanol, ethanol, ethyl acetate, and petroleum ether. Soybean oil without added STP was used as a negative control, and soybean oil samples containing 0.02% butylated hydroxy toluene(BHT) and $\alpha$-tocopherol were used as positive control, respectively. Each sample was stored at $50^{\circ}C$ for 30 days. The oxidation levels of these samples were determined by measuring their acid values, peroxide values, and thiobarbituric acid(TBA) values. The soybean oil samples containing the STP extracts had lower oxidation levels than both the negative control and $\alpha$-tocopherol positive control, and the sample containing the 0.05% methanol extracts had the lowest oxidation. According to the Rancimat method, the methanol extract(320 min) and ethanol extract(316 min) demonstrated longer induction periods as, compared to the control(253 min), $\alpha$-tocopherol(255 min), and BHT(309 min) samples. For the Maejakgwa, acid values increased over the storage period, however, the samples made with STP had lower values than the control group. Peroxide values increased rapidly for 30 days and then decreased. The TBA values of the Maejakgwa samples made with 3% and 9% STP were lower than those of the 15% STP sample and the control. In conclusion, the oxidative stability of soybean oil containing solvent extracts of STP and Maejakgwa made with STP were increased.

• Food Science and Preservation
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• v.10 no.3
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• pp.370-375
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• 2003

To obtain the oil sesame, walnut, whole wheat, and rice bran were extracted for 1, 3, or 6 hr by a shanking water bath(35$^{\circ}C$ and 100 rpm), and by soxhlet extractor(80$^{\circ}C$) for 1, 3 or 6 hr, respectively. The highest yield of extracted oil was obtained from the walnut(63.07％ weight) and the whole wheat showed the lowest extraction yield of oil(1.13％ weight). Major fatty acids from the extracted oils were linoleic, oleic, and palmitic acid. The maximum contents of total phytosterol in sesame, walnut, whole wheat, and rice bran were 0.44, 1.57, 2.25, and 2.03(％ weight), respectively. Besides, total tocopherol contents in sesame, walnut, whole wheat, and rice bran were maxima 3.42, 0.16, 2.92, and 0.07(％ weight), respectively. From the extracted oils, structured lipids(SL) were synthesized by the interesterification reaction with conjugated linoleic acid(CLA) in a shanking water bath at 55$^{\circ}C$. When the reactions(1:3 substrate molar ratio, extracted oil:CLA) were conducted for 24 hr, maxima 23.75 mol％ of CLA incorporation was obtained from walnut oil and, in other cases, 16.28 - 19.15 mol％ of CLA was found in the produced SL triacylglycerol molecules.

• Clean Technology
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• v.27 no.2
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• pp.190-197
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• 2021

Kraft lignin is a by-product of the pulp and paper industry, obtained as a black liquor after the extraction of cellulose from wood through the Kraft pulping process. Right now, kraft lignin is utilized as a low-grade boiler fuel to provide heat and power but can be converted into high-calorific biofuels or high-value chemicals once the efficient catalytic depolymerization process is developed. In this work, the multi-functional catalyst of Ru-Mg-Al-oxide, which contains hydrogenation metals, acid, and base sites for the effective depolymerization of kraft lignin are prepared, and its lignin depolymerization efficiency is evaluated. In order to understand the role of different active sites in the lignin depolymerization, the three different catalysts of MgO, Mg-Al-oxide, and Ru-Mg-Al-oxide were synthesized, and their lignin depolymerization activity was compared in terms of the yield and the average molecular weight of bio-oil, as well as the yield of phenolic monomers contained in the bio-oil. Among the catalysts tested, the Ru-Mg-Al-oxide catalyst exhibited the highest yield of bio-oil and phenolic monomers due to the synergy between active sites. Furthermore, in order to maximize the extent of lignin depolymerization over the Ru-Mg-Al-oxide, the effects of reaction conditions (i.e., temperature, time, and catalyst loading amount) on the lignin depolymerization were investigated. Overall, the highest bio-oil yield of 72% and the 3.5 times higher yield of phenolic monomers than that without a catalyst were successfully achieved at 350 ℃ and 10% catalyst loading after 4 h reaction time.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.4
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• pp.335-341
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• 2022

Proso millet (Pacnicum miliaceum L.) has a various of functional substances, so the demand is increasing as interest in human health benefits. In particular, miliacin, a triterpenoid in proso millet, is known to be effective in hair loss due to its promoting metabolism and proliferation of keratinocytes and showing protective effects from apoptosis. In this study, proso millet oil was extracted and analyzed by GC/MS using the extraction method of unsaponifiable substances after saponification reaction. The components of proso millet oil were confirmed through qualitative analysis by GC/MS. The miliacin content of 5 varieties of proso millet and 2 varieties of foxtail for comparison was analyzed. In the result, components of pentacyclic triterpenes such as β-amyrine and lupeol were detected in proso millet, and the content of miliacin was highest in Hallachal at 370.38±0.04 ㎍/100 mg oil. In addition, the content of miliacin was not detected in Samdachal and Samdamae, which are varieties of foxtail millet.

• Journal of Food Hygiene and Safety
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• v.38 no.3
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• pp.89-98
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• 2023

Currently, no guidelines exist regarding the maximum residues of pesticides in edible oil which is a processed food commonly consumed in Korea. This lack of guidelines hinders the evaluation of the safety of edible oil in terms of pesticide contamination. In this study, an analysis method based on heat distillation and GC-MS/MS was established by optimizing the extraction and purification procedure for 68 pesticides. Important variables in the thermal distillation procedure included heating temperature and time, and we found the nitrogen flow rate as a mobile phase and the type of dissolving solvent were not considerably affected. The determination coefficient (R²) of the residual pesticide was 0.99 or higher, and the quantitative limit (LOQ) was 0.01-0.02 mg/L. The average recovery rate (n=5) was 66.1-120.0% and the relative standard deviation was lower than ±10% when 68 pesticides were spiked at concentrations of 0.01-0.02, 0.1, and 0.5 mg/L. In addition, the within-laboratory precision was less than ±11%, meeting the Korea Food and Drug Safety Evaluation Institute's Guidelines on Standard Procedures for Preparing Food Testing Methods (2016). Therefore, the test method developed in this study can be used as a test method for managing the safety of the residual pesticide concentration in edible oil.

• Journal of Soil and Groundwater Environment
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• v.7 no.4
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• pp.77-86
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• 2002

Surfactant enhanced in-situ soil flushing was performed to remediate the soil and groundwater at an oil contaminated site, where had been used as a military vehicle repair area for 40 years. A section from the contaminated site (4.5 m $\times$ 4.5 m $\times$ 6.0 m) was selected for the research, which was composed of heterogeneous sandy and silt-sandy soils with average $K_d$ of 2.0$\times$$10^{-4}$cm/sec. Two percent of sorbitan monooleate (POE 20) and 0.07% of iso-prophyl alcohol were mixed for the surfactant solution and 3 pore volumes of surfactant solution were injected to remove oil from the contaminated section. Four injection wells and two extraction wells were built in the section to flush surfactant solution. Water samples taken from extraction wells and the storage tank were analyzed on a gas-chromatography (GC) for TPH concentration in the effluent with different time. Five pore volumes of solution were extracted while TPH concentration in soil and groundwater at the section were below the Waste Water Discharge Limit (WWDL). The effluent TPH concentration from wells with only water flushing was below 10 ppm. However, the effluent concentration using surfactant solution flushing increased to 1751 ppm, which was more than 170 times compared with the concentration with only water flushing. Total 18.5 kg of oil (TPH) was removed from the soil and groundwater at the section. The concentration of heavy metals in the effluent solution also increased with the increase of TPH concentration, suggesting that the surfactant enhanced in-situ flushing be available to remove not only oil but heavy metals from contaminated sites. The removal efficiency of surfactant enhanced in-situ flushing was investigated at the real contaminated site in Korea. Results suggest that in-situ soil flushing could be a successful process to remediate contaminated sites distributed in Korea.

• Journal of Microbiology and Biotechnology
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• v.6 no.3
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• pp.184-188
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• 1996

The Acinetobacter sp. BE-254 isolated from soil sources produced a bioemulsifier in the medium supplemented with n-hexadecane. This bioemulsifier was purified by the procedures of fractionation (ammonium sulfate and chilled acetone), extraction by hexane, and column chromatography on silica gel 60. The results from various color reactions indicated that the bioemulsifier was a glycolipid. The purified emulsifier was very stable at pHs ranging from 4 to 10 and under heat treatment at $100^{\circ}C$ for 30 min. Emulsification activity was also hardly influenced by pH. The critical micelle concentration (CMC) and surface tension at the point ($\gamma_{cmc}$) of the bioemulsifier were approximately 35 mg/l and 30 mN/m, respectively. The bioemulsifier showed a fairly good emulsification activity and stability in comparison with other commercial emulsifiers in the basic formula composed of emulsifier, oil, and water.