• International Journal of Industrial Entomology and Biomaterials
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• v.27 no.1
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• pp.180-184
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• 2013

Recently, silk sericin has attracted the attention of researchers owing to its useful properties as a biomaterial including 1) good wound healing and cell activities, 2) fast gelation character, and 3) high water retention property. In the present study, silk sericin was prepared using different extraction times in hot water and the effect of extraction time on the rheological properties of sericin solutions and gels was examined. It was found that the production yield of sericin increased with extraction time. The shear viscosity of sericin solutions and gels decreased with increasing extraction time due to a decrease in sericin molecular weight. When the sericin solution transformed to a gel, the viscosity increased and the shear thinning behavior was more evident. In addition, the shear stress measurements indicated that the slip between the sericin samples and the measuring plate of the rheometer was increased by the gelation of sericin. The compression strength of sericin gel could be increased remarkably (by more than 100 fold) by preparation using the freezing and thawing method.

• The Korean Journal of Food And Nutrition
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• v.13 no.1
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• pp.45-52
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• 2000

In order to select the optimum ethanol concentration for extraction of volatile components in cinnamon, the dried cinnamon was extracted with water and 30∼90% ethanol. The volatile components of cinnamon extracts were isolated by the simultaneous distillation extraction method using Likens and Nickerson's extraction apparatus, and analyzed by GC-MS. In cinnamon bark powder 45 components were detected and 21 components were identified. The major component of cinnamon bark powder was cinnamic aldehyde. In water extract of cinnamon, volatile components were not extracted sufficiently. The volatile components of cinnamon were increased with the increment of ethanol concentraction upto 70%. The volatile component of 70% ethanol extract showed similar pattern and amount to cinnamon bark powder. But in 90% ethanol extracts, the number and amount of volatile component were reduced. The above data suggested that 70% ethanol was the most effective solvent for volatile components extraction of cinnamon.

• Journal of the Korean Society of Safety
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• v.8 no.2
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• pp.44-50
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• 1993

The objective of this study was to investigate the extraction of chromium(Vl) ion in waste water through the liquid surfactant membrane with open-type Perforated Reciprocating-Plate Column. Extraction experiments were conducted to measure the effect of flow characteristics of continuous and dispersed phase and stroke velocity, sodium hydroxide concentraction in internal aqueous phase, sulfuric acid concentraction in outer phase, and residence time distribution and measured extraction velocity. The result of experiments showed that extraction velocity of chromium ion was maximum when stroke velocity was 180 1/min and dispersion phase velocity was 30m11min, continuous phase velocity was 20m1/min. Extraction velocity of chromium ion increased with increasing difference of hydrogen ion concentraction of dispersion and continuous phase and column stage decreased.

• Bulletin of the Korean Chemical Society
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• v.31 no.5
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• pp.1192-1198
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• 2010

Pharmaceuticals and personal care products (PPCPs) are emerging contaminants in the aquatic environment. Many pharmaceuticals are not completely removed during wastewater treatment, leading to their presence in wastewater treatment effluents, rivers, lakes, and ground water. Here, we developed analytical methods for monitoring ten pharmaceuticals from surface water by LC/ESI-MS/MS. For sample clean-up and extraction, MCX (mixed cation exchange) and HLB (hydrophilic-lipophilic balance) solid-phase extraction (SPE) cartridges were used. The limits of detection (LOD) in distilled water and the blank surface water were in the range of 0.006 - 0.65 and 1.66 - 45.05 pg/mL, respectively. The limits of quantitation (LOQ) for the distilled water and the blank surface water were in the range of 0.02 - 2.17 and 5.52 - 150.15 pg/mL, respectively. The absolute recoveries for fortified water samples were between 62.1% and 125.4%. Intra-day precision and accuracy for the blank surface water were 2.9% - 24.1% (R.S.D.) and -16.3% - 16.3% (bias), respectively. In surface wastewater near rivers, chlortetracycline and acetylsalicylic acid were detected frequently in the range of 0.017 - 5.404 and 0.029 - 0.269 ng/mL, respectively. Surface water near rivers had higher levels than surface water of domestic treatment plants.

• Journal of Korea Water Resources Association
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• v.32 no.2
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• pp.121-129
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• 1999

When the soil vapor extraction as a remediation method of contaminated soil and groundwater has been used, the effects of curtain wall, mode of pump operation and magnitude of extraction flowrate were examined by numerical simulation. Consequently, it was found that the removal rate was enhanced in case that the curtain wall was established around the extraction well with the extraction pumps operated alternatively. It was because that the removal of high density gas around the extraction well was possible. It was found that the removal efficiency of TCE gas did not depend on the extraction flowrate. However, the removal rate of TCE gas at varying extraction flowrate was not enhanced flowrate increase.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.5
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• pp.638-648
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• 2004

In many drinking water treatment plants, chlorination process is one of the main techniques used for the disinfection of water. This disinfecting treatment leads to the formation of haloacetic acid (HAAs). In this study, headspace solid-phase microextraction (HS-SPME) was studied as a possible alternative to liquid-liquid extraction for the analysis of HAAs in drinking water. The method involves direct derivatization of the acids to their methyl esters without methyl tert-butyl ether (MTBE) extraction, followed by HS-SPME with a $2cm-50/30{\mu}m$ divinylbenzene/carboxen/polydimethylsiloxane fiber. The effects of experimental parameters such as selection of SPME fiber, the volume of sulphuric acid and methanol, derivatization temperature and time, the addition of salts, extraction temperature and time, and desorption time on the analysis were investigated. Analytical parameters such as linearity, repeatability and limit of detection were also evaluated. The $2cm-50/30{\mu}m$-divinylbenzene/carboxen/polydimethylsiloxane fiber, sulphuric acid of 1ml, methanol of 3ml, derivatization temperature of $50^{\circ}C$ derivatization time of 2hrs, sodium chloride salt of 10g, extraction time of 30 minutes, extraction temperature of $20^{\circ}C$ and desorption time of 1 minute at $260^{\circ}C$ were selected as the optimal experimental conditions for the analysis of HAAs. The linearities ($r^2$), relative standard deviations (%RSD) and limits of detection (LOD) for HAAs were 0.9978~0.9991, 1.1~9.8% and $0.05{\sim}0.2{\mu}g/l$, respectively.

• Journal of Environmental Health Sciences
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• v.19 no.2
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• pp.16-22
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• 1993

In recent years, great concern for the improvement of drinking water quality has been arising due to the contamination of the raw and treated water. So trihalomethanes (THMs) and some other volatile organic compounds (VOCs), potential carcinogenic substances, rendered the government to take some countermeasurements for clean water service in the dimension of public health. In this study, we used liquid-liquid extraction method as a rapid simple method for determination of VOCs through eluation with n-Pentane in water. The aim with the present study has been to determine the changes of recovery and reproducibility of the method under the various conditions in extraction solvents, solvent ratio and extraction time, and to observe the concentrations under the various temperature and pH during storage.

• Journal of Mushroom
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• v.12 no.4
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• pp.299-303
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• 2014

This study was to comparative analysis that different methods of extraction about total sugar content which the major functional components of edible and medicinal mushrooms. Through the phenol-sulfuric acid method was measured that Hot water extraction, acid extraction, and alkaline extraction. Drawing the standard curve to obtain the concentration of the glucose solution and the sample by applying the measured absorbance on the standard curve. Total sugar contents was measured after extraction with different solvents.(Hot water, 70% EtOH, 80% MeOH). The level of total sugar in Cordyceps militaris is highest in the hot water extraction with 658.4(${\mu}g/g$) and Coriolus versicolor in 649.7(${\mu}g/g$) and 679.0(${\mu}g/g$) was found as the highest in the acid extraction and the alkaline extraction. C. militaris and ASI 7025 showed the highest level in the hot water extraction. Finally, C. versicolor, Sparassis crispa showed that higher than the other mushrooms at the 1hr, 2hr microwave extraction. It was varied total sugar content according to the different extraction solvent and the extraction method.

• Journal of Ginseng Research
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• v.15 no.3
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• pp.192-196
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• 1991

As a part of studios on the Quality control of index components in crude drug preparations, extraction yields of ginseng saponins from crude drug extracts were identified by TLC and quantified by HPLC. So-Shi-Ho-Tang(小柴胡湯), Sa-Kun-Ja-Tang(四君子湯), Yook-Kun-Ja-Tang(六君子湯) and In-sam-Tang(人蔘湯) were extracted with water, 30%-ethanol, 50%-ethanol, 80%-ethanol and absolute ethanol to analyze ginseng saponins in the crude drug extracts prepared with various concentrations of ethanol. Ginseng saponins were extracted considerably more from the extracts with higher concentrations of ethanol than those with water or lower concentrations of ethanol. Extraction yields of ginseng-side-Rb$_1$, -Rb$_2$ and -R$_c$ from four crude drug preparations were the lowest as 4.9~45.9%, 5.0~40.1, and 6.3~43.7% in water extract and the highest as 29.5~62.6%, 26.7~61.4% and 31.4~62.0% in absolute ethanol extract, compared with those of 80%-methanol extracts.

• Advances in materials Research
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• v.9 no.2
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• pp.109-114
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• 2020

The purpose of this study was to observe the trend of compounds release from acrylic resin oral prosthesis when used for drug delivery as well as a restoration. In this study, 10 specimens of heat-cured polymethylmethacrylate material were prepared and loaded with methylene blue biological stain. The specimens were then submerged in vials with 5 ml distilled water for 24 hours. The extraction procedure continued for 4 days, each day the specimens were immersed in another 5 ml distilled water vial. All extracted solutions were analyzed by visible light spectroscopy for absorbance comparison. The statistical results showed that the absorbance values were significantly different in the first day of extraction than the following days. However, there was no statistical difference among the 2^nd, 3^rd and 4^th days of extraction. Biological stain loading to acrylic resin at the mixing stage, and then after extraction in distilled water, showed a burst release during the first day followed by a constant release during the following few days.