• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.515-518
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• 1997

Resident time of the centrifugal extractor for organic phase extraction using a height controlled separator weir and a divert plate is the important factor that affects significantly the chemical material extraction and the productivity in the chemical and mechanical processes. In this paper, it describes the design of the device for extraction of an organic phase from radioactive wastes, and considers phase separating weir and divert disk, both being designed to be adjustable in their positions, for effectively separating an organic phase. A height-adjustable separating weir unit used for separating the organic phase from the aqueous phase using a phase separating weir and designed to control the height of the separating weir as desired so as to allow the weir to be positioned at a boundary layer between two separated phases. The centrifugal extractor controls satisfactorily the mixed reaction time of two phases within the separator regardless of the variations of the mixing ratio of the two phases and the rotating speed of the extractor, is designed to be adjustable in its position in the vertical direction, thus allowing the user to appropriately select the mixed reaction time of the two phases within the extractor as desired. From development of a centrifugal extractor, it can effectively recover such usable elements, and preferably reducing the output quantity of radioactive wastes.

• KSBB Journal
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• v.23 no.4
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• pp.281-284
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• 2008

A simple and efficient microwave-assisted extraction procedure was developed and optimized for the extraction of paclitaxel from the plant cell cultures of Taxus chinensis. The biomass, immersed in a methanol-water mixture, was irradiated with microwaves in a closed-vessel system. The microwave-assisted extraction was compared with the existing conventional solvent extraction in terms of yield, extraction time, and solvent consumption. The use of microwave energy allows rapid recovery of paclitaxel from biomass and dramatically reduces extraction time and solvent usage compared to conventional solvent extraction. The paclitaxel was completely extracted from biomass by microwave-assisted extraction for 3 min at $50^{\circ}C$, for 6 min at $30^{\circ}C$ and $40^{\circ}C$, respectively.

• Journal of Applied Biological Chemistry
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• v.58 no.2
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• pp.117-124
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• 2015

The extract of white rose petals has an antioxidant effect and can be used to treat allergic disease. The purpose of this study was to identify optimal conditions for extracting antioxidative compounds from white rose petals with 2,2-diphenyl-1-picrylhydrazyl scavenging activities. A response surface methodology based on a central composite design was used to investigate the effects of three independent variables: ethanol concentration ($X_1$), extraction temperature ($X_2$), and extraction time ($X_3$). The estimated optimal conditions for obtaining phenolic compounds with antioxidant activities were as follows: ethanol concentration of 42% ($X_1$), extraction time of 80 min ($X_3$), and extraction temperature of $75^{\circ}C$ ($X_2$). The estimated optimal conditions for obtaining flavonoid compounds with antioxidant effects were an ethanol concentration of 41% ($X_1$), extraction time of 119 min ($X_3$), and an extraction temperature of $75^{\circ}C$ ($X_2$). Under these conditions, predicted response values for the phenolic and flavonoid contents were 243.5 mg gallic acid equivalent/g dry mass and 19.93 mg catechin equivalent (CE)/g dry mass, respectively.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.227-230
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• 2004

Two extraction techniques, Ultrasonic and Microwave extraction method, were tested for the determination of arsenic in contaminated soil SRM (Montana Soil). The extraction mixture was prepared by mixing 1 M ortho-phosphoric acid and 0.1 M ascorbic acid. This extractant was known to preserve arsenic species. The appropriate extraction time was 10 min to 20 min and the recovery rate was about 80%. A coupled system, SPE-HG-ICP-AES, was used for the determination of inorganic arsenic species. The detection limit was around 2 $\mu\textrm{g}$/1 and the linearity of calibration curve was better than $R^2$=0.99.

• Food Science and Preservation
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• v.17 no.5
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• pp.659-666
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• 2010

A central composite design was used to investigate the effects of the three independent variables of extraction temperature ($X_1$), ethanol concentration ($X_2$), and extraction time ($X_3$), on dependent variables including yield ($Y_1$), total phenol levels ($Y_2$), electron-donating ability ($Y_3$), brownness ($Y_4$), and reducing sugar content ($Y_5$) of Vitis Coignetiae. Yield was affected by extraction temperature and time. The maximum yield was obtained at $91.62^{\circ}C(X_1)$, and, 25.37% (w/v) ethanol ($X_2$), after 317.70 min of extraction ($X_3$), evident as a saddle when displayed graphically. Total phenol levels were essentially unaffected by extraction temperature or ethanol concentration, but were highly influenced by extraction time. The maximum total phenol levels was 4,763.46 GAE mg/100 g obtained at $88.20^{\circ}C(X_1)$, and 47.79% (w/v) ethanol ($X_2$), after 349.32 min ($X_3$) of extraction. Electron-donating ability (EDA) was affected by extraction temperature and time. Maximum EDA was 55.90% at $86.72^{\circ}C(X_1)$, 50.61% (w/v) ethanol ($X_2$), and 265.96 min ($X_3$) of extration time, again shown by a graphical saddle. Brownness was affected by extraction time. The maximum extent of brown coloration was obtained at $82.66^{\circ}C(X_1)$, 99.27% (w/v) ethanol ($X_2$), and 252.63 min of extraction time ($X_3$), once again shown by graphical saddle. The maximum reducing sugar content was obtained at $96.24^{\circ}C(X_1)$, 22.59% (w/v) ethanol ($X_2$), and 216.06 min extraction time($X_3$).

• Resources Recycling
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• v.15 no.4 s.72
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• pp.13-18
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• 2006

This study was to investigate the extraction characteristics of extraction resins containing HEH/EHP for Gadolinium solution. The experiments were carried out with the variation of equilibrium pH and initial concentration of Gd. The optimum extraction time was 90 mins on Gd extraction using resin. The extraction ratio(%) was increased by increasing equilibrium pH from pH 1.0 to 2.0. The experimentally measured amounts of Gd on resins at equilibrium agreed well with those predicted using Freundlich's isotherm.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.3
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• pp.348-354
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• 2007

Extraction characteristics of ginger (Zingiber officinale) and the functional properties of the corresponding extracts were monitored by the response surface methodology (RSM). The maximum extraction yield of 38.83% was obtained under the specific extraction conditions, such as microwave power of 126.68 W, ethanol concentration of 53.39% and extraction time of 8.15 min. The maximum electron donating ability (EDA) was found as 77.92% at the conditions of 58.25 W microwave power, 91.87% ethanol concentration and 5.54 min extraction time. The maximum inhibitory effect on tyrosinase was 79.39% at 106.08 W, 2.06% and 5.61 min. The maximum polyphenol content was 105.59% under the extraction conditions of 81.82 W, 99.52% and 4.06 min. Based on superimposition of four dimensional RSM with respect to extraction yield and electron donating ability and polyphenol content obtained under the various extraction conditions, the optimum ranges of extraction conditions were found to be microwave power of $0{\sim}80\;W$, ethanol concentration of $0{\sim}40%$ and extraction time of $3{\sim}7$ min.

• Horticultural Science & Technology
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• v.28 no.4
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• pp.685-690
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• 2010

Rubiadin, a major compound of noni ($Morinda$ $citrifolia$) adventitious root, is highly valued in pharmaceutical industry due to hepatoprotective activity. To dissect rubiadin's effective extraction condition, extraction process of noni adventitious roots was performed with different solvent types, ratio of water to methanol (water, 20, 40, 60, 80, and 100% of methanol), extraction time, and extraction method. In contrast, we also developed a reverse- phase HPLC assay method to determine rubiadin from noni adventitious roots. The HPLC assay of rubiadin was performed by C-18 column using a gradient solvent system of methanol and water with UV detector at 280 nm. The extraction efficiency of different types of solvents were increased in order of methanol (0.08%) > ethanol (0.05%) > acetonitrile (0.03%) > acetone (0.02%) and methylene chloride (0.02%). The results of rubiadin extraction using different solvents showed that 1 hour of ultrasonic extraction was effective in order of 60% methanol (0.21%) > 80% methanol (0.13%) > 100% methanol (0.07%), 40% methanol (0.07%) and 2 hours of reflux extraction was effective in order of 60% methanol (0.21%) > 40% methanol (0.17%) > 80% methanol (0.14%). To compare the extraction efficiency of rubiadin according to the extraction methods and time for high rubiadin content, the extracts of rubiadin in noni adventitious roots were isolated with the methods of ultrasonic extraction, shaking extraction and reflux extraction. Rubiadin extracted from the methods of ultrasonic waves and shaking displayed the highest contents at 8 and 24 hours, respectively.

• Korean Journal of Materials Research
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• v.34 no.5
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• pp.247-253
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• 2024

The separation of zirconium and hafnium using tributyl phosphate (TBP)-Dodecane extractants in nitric acid medium was performed. Zirconium oxychloride, used as extraction feed, was obtained from the synthesis of Kalimantan zircon sand concentrate smelted using NaOH. The extraction process was carried out by dissolving chloride-based metals in nitric acid media in the presence of sodium nitrate using TBP-Dodecane as an extractant. Some of the extraction parameters carried out in this study include variations in organic phase and aqueous phase (O/A), variations in contact time, and variations in nitric acid concentration. Extraction was carried out using a mechanical shaker according to the parameter conditions. X-ray fluorescence (XRF) was used for elemental (Zr and Hf) composition analysis of the aqueous solution. The results showed that zirconium was separated from hafnium at optimum conditions with an organic/aqueous ratio of 1:5, contact time of 75 min, and an HNO₃ concentration of 7 M. The resulting separation factor of zirconium and hafnium using TBP-Dodecane was 14.4887.

• Food Science and Preservation
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• v.13 no.6
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• pp.732-739
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• 2006

This study was performed to investigate the changes in quality properties of extract from roasted Pleurotus eryngii by microwave-assisted extraction (MAE). MAE was carried out under different conditions including ethanol concentration, extraction time and microwave power. Total phenolics compound contents, electron donating ability (EDA) and nitrite-scavenging ability at pH 1.2 were high at 50% ethanol concentration. Superoxide dismutase (SOD)-like activity was high at 75% ethanol concentration. Soluble solid and total phenolics compound content decreased as extending extraction time up to 7 min. EDA decreased as increased extraction time. SOD-like activity and nitrite-scavenging ability were not significantly different. The highest soluble solid content, total phenolics compound content and EDA were obtained at 100 W extraction of microwave power. SOD-like activity was high at 25 W. But microwave power did not significantly affect the nitrite-scavenging ability.