• Applied Chemistry for Engineering
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• v.5 no.1
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• pp.121-126
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• 1994

To elucidate the effect on the reactive extraction of acetic acid, various carriers and modifiers were investigated. Carriers used were secondary and tertiary amines and solvation extractant. Diluent was n-butylacetate. Modifiers were 4-nonylphenol, TBP(Tti-n-butyl phospate) and isodecanol. Besides the effect of temperature and pH in aqueous phase were studied. The mixture of 50% tri-n-octyl/n-decylamine tertiary amine, gave higher degree of extraction and selectivity than other extractants in the extraction of acetic acid. It was found that 4-nonylphenol as modifier fairly good. The degree of extraction was higher with decreasing the pH in aquous phase and the temperature of extraction system.

• Journal of the Korean Society of Tobacco Science
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• v.23 no.1
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• pp.65-70
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• 2001

In order to compare the extraction patterns of main components from the raw material between the extraction methods, the aerial parts (dried stem, leaves, and flowers) of Agastache rugosa were extracted by SDE simultaneous steam distillation & extraction) and SFE (supercritical fluid extraction). Volatile components of essential oil and extract were identified by GC and GC-MSD. The contents of essential oil extracted by SDE were 0.49% in aerial part of Agastache rugosa on dry basis. Major components were methyl chavicol(27.2%), isomenthone(24.6%), hexadecanoic acid(13.0%). menthone (5.5%) among 32 kinds of components confirmed in essential oil. On the other hand, the contents of SFE extracts revealed 3.21% on dry basis, 6 times higher than those of SDE. Major components were isomenthone(15.3%), hexadecanoic acid(13.7%), methyl chavicol(12.6%), benzoic acid(3.8%) among 33 kinds of components identified in extract.

• Journal of Microbiology and Biotechnology
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• v.6 no.5
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• pp.358-360
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• 1996

Solvent extraction, soxhlet method, and supercritical fluid extracion were considered, respectively, as the method of choice for the recovery of DHA from lyophilized Thraustochitrium sp., and the results of corresponding extraction were compared. Supercritical fluid extraction seems to be the most appropriate process with respect to time, process simplicity, and extractant intoxicity.

• Journal of Environmental Science International
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• v.9 no.1
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• pp.43-47
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• 2000

A study on the remediation of heavily for ion contaminated soils from abandoned iron mine was carried out, using ex-situ extraction process. Also, oxalic acid as a complex agent was evaluated as a function of concentration, reaction time and mixing ratio of washing agent in order to evaluate Fe removability of the soil contaminated from the abandoned iron mine. Oxalic acid showed a better extraction performance than 0.1N-HCl, i.e., the concentrations of Fe ion extracted from the abandoned mine for the former at uncontrolled pH and the latter were 1,750 ppm and 1,079 ppm, respectively. The optimum washing condition of oxalic acid was in the ratio of 1:5 and 1:10 between soil and acid solution during l hr reaction. The total concentrations of Fe ion by oxalic acid and EDTA at three repeated extraction, were 4,554 ppm and 864 ppm, respectively. The recovery of Fe ions from washing solution was achieved, forming hydroxide precipitation and metal sulfide under excess of calcium hydroxide and sodium sulfide. In addition, the amounted of sodium sulfide and calcium hydroxide for the optimal revovery of Fe were 15g/$\ell$ and 5g/$\ell$ from the oxalic acid complexes, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.5
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• pp.860-865
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• 1997

Investigations were performed on the effects of extraction temperature, pressure, time on solubility and selectivity of egg yolk lipid and cholesterol, and color and fatty acid composition of the residue in supercritical carbon dioxide(SC-Co$_2$) extraction. Lipid and cholesterol solubility increased as the increase of Co$_2$ density and was found to strongly depend on the extraction pressure rather than the extraction temperature. The relative concentration of cholesterol in the extract increased with an increase in temperature and decreased with an increase in pressure and extraction time. extraction of dried eg yolk for 3hr at 4$0^{\circ}C$/276 bar removed 46.1% of cholesterol from the residual egg yolk with a yield of 63.2%. SC-Co$_2$ extraction produced a lighter color egg yolk with less redness and yellowness. As the extraction time increased, the resultant residual egg yolk became more saturated with fatty acids. SC-$CO_2$ extraction offers a safe, natural method for removing cholesterol from dried egg yolk.

• International Journal of Industrial Entomology and Biomaterials
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• v.26 no.2
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• pp.113-118
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• 2013

In this study, silk sericin films were prepared using different extraction methods, and the molecular conformation of sericin was examined using Fourier-transform infrared spectroscopy with attenuated total reflection geometry. Additionally, the effect of the film side (air-facing side or plate-facing side) on the molecular conformation of the sericin films was investigated. Interestingly, the molecular conformation of the sericin film depended on the film side. The molecular conformation of air-facing side of the sericin film was significantly influenced by extraction solution and time. The ${\beta}$-sheet crystallization and the crystallinity index of the sericin film markedly increased with an increase in the extraction time in hot water. The order of the crystallinity indices for the sericin films obtained with different extraction solutions was as follows: citric acid solution > urea solution >> hot water. In contrast, no remarkable differences were observed in the molecular conformation of the plate-facing side of the sericin film after extraction in hot water for different time periods. Urea and citric acid solution extractions showed remarkably higher crystallinity indices for sericin than those obtained after hot water extraction. However, no significant differences were observed in the crystallinity index of sericin between urea and citric acid solution extraction in plate-facing side of the film.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.3
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• pp.207-212
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• 2001

Supercritical fluid extraction was explored as a method for removing lipids and bad odor from tuna viscera. Selected conditions of extraction pressure, time, temperature and sample size were evaluated for effective removal of lipids and bad odor, Supercritical carbon dioxide was used as a solvent and the extraction was performed at semi-batch flow type. The experimental conditions used in this work was the range of pressure from 1,500 psig to 2,000 psig, the temperature from $25^{\circ}C\;to\;40^{\circ}C$ and dried sample size from 0.2 mm to 1.0 mm. The main fatty acids extracted from tuna viscera were palmitic acid (16: 0) heptadecenoic acid (17: 1) oleic acid (18: 1) and docosahexaenoic acid (22: 6). Protein concentrate was obtained without deformation the optimum condition at $35^{\circ}C$, 1,800 psig and 0.25 mm of the size. In the concentrate after supercritical carbon dioxide extraction, the major amino acids were glutamic acid, leucine and lysine.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.8
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• pp.1062-1069
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• 2007

Response surface methodology was employed to optimize extraction conditions for finding the maximizing the functional properties of roasted Pleurotus eryngii. Based on the central composite design, independent variables were ethanol concentration ($0{\sim}100%$), extraction time ($1{\sim}9$ min) and microwave power ($25{\sim}125$ W). Soluble solid content, electron donating ability and nitrite-scavenging ability were mainly affected by ethanol concentration, but ACE inhibition activity was largely affected by extraction time. The optimum ranges of extraction conditions resulting from superimposing the response surface were predicted to be ethanol concentration ($25{\sim}50%$), extraction time ($3{\sim}9$ min) and microwave power ($80{\sim}125$ W). Total protein and total phenolic compound content of optimal extracts were 45.80 mg/g and 7.42 mg/g, respectively. In phenolic compounds of roasted Pleurotus eryngii extracts, protocatechuic acid was the highest concentration at 1226.32 ${\mu}g/g$, followed by salicylic acid, catechin, p-hydroxybenzoic acid, caffeic acid, coumaric acid and hesperidin.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.9 no.2
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• pp.135-144
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• 1999

The purposes of this study were to survey types of pretreatment methods adopted by industrial hygiene laboratories in Korea for extracting heavy metals in welding fume samples and to compare performances of two pretreatment methods, the acid extraction and the microwave digestion, in extracting heavy metals contained in the real workplace samples from various welding jobs including arc, argon, and carbon dioxide. A total of 25 analytical chemists in the industrial hygiene laboratories participating the quality control program directed by the Korea Industrial Safety Corporation were interviewed by telephone. For the purpose of comparing performance of extracting heavy metals from real workplace samples, a total of 53 welders from 21 workplaces located in Anyang, Uiwang, and Kunpo areas were sampled from the period of March 22, 1999 to April 20, 1999. It was found that the most frequently adopted method for samples from the quality control program was the acid extraction method(40%) followed by the NIOSH 7300 method(36%). The NIOSH method, however, was the dominant method(36%) for samples from workplace followed by the acid extraction method(28%). In this study, two extraction methods, the acid extraction and the microwave digestion, were compared in terms of recovery rate, accuracy, and precision for both manganese and chromium. Both methods produced comparable results for the samples prepared for the quality control program. In contrast, concentrations of two heavy metals determined from real workplace samples pretreated with the microwave digestion method were statis tically significantly higher, manganese(166%) and chromium (200%), than those of utilizing the acid extraction method. These findings were consistent regardless of types of welding techniques used. The results of this study clearly show the importance of verifying the analytical performances of extraction methods for heavy metals not only for the samples from the quality control program but also from the real world samples collected from welding jobs.

• Korean Journal of Medicinal Crop Science
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• v.20 no.5
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• pp.331-338
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• 2012

In the present work, mulberry fruit extracts by four extraction processes, namely wet pressing extraction (WPE), hot-water extraction (HWE), enzymatic hydrolysis (EH), and lactic-acid bacteria fermentation (LBF) by Lactobacillus plantarum TO-2100, were analyzed for nutrients and functional compounds. The sugar contents of extracts by WPE, HWE, EH, and LBF were 12.0, 10.9, 14.5, and 14.3 brix, respectively, and the extraction yields by EH and LBF were 1.65 and 1.50 times higher than those by WPE. Among the organic acids, tartaric acid and malic acid contents were the highest in the extracts by WPE. Acetic acid was best extracted by LBF, and citric acid was best extracted by EH. Lactic acid was detected only in LBF. The extracts by EH showed the highest contents of all vitamins with an exception that the extracts by LBF showed the highest contents of the folic acid, vitamin B12, and vitamin C. We also noted that vitamin B group was not detected in the extracts by LBF. The extracts by EH showed the highest contents of all the amino acids, whereas LBF showed the lowest. Polyphenol contents of extracts by EH and LBF were 3.05 and 2.51 times more than those by WPE respectively. Anthocyanin contents were 7.66, 7.14 times higher for EH and LBF compare to WPE. We manufactured mulberry fruit granular teas with different compositions and tested them for their sensory characteristics. We found that 15% mulberry fruit extracts by enzymatic hydrolysis and 85% dextrin composition gave the most satisfactory result.