• Journal of Environmental Science International
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• v.18 no.3
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• pp.345-353
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• 2009

The purpose of this study is to examine the health of beauty salon workers through the utilization of questionnaires concerning the extent of exposure to organic solvents found in the air of some beauty salons and any resultant symptoms in employees. The subjects were 36 employees from 10 beauty salons who agreed to participate in this study. The degree of exposure to organic solvents in the air of beauty salons was measured from September 1, 2008 to September 30, 2008. A survey of symptoms that occurred due to exposure to these solvents was also performed. The results were as follows: questionnaires were collected and analyzed from a total of 36 subjects. Of these, 28(77.8%) were female and 8(22.2%) were male. The mean age was 29.08. The mean working period was 7.13 years. Sixteen subjects attended programs at universities while 11 went to beauty schools for vocational education. When testing the concentration of organic solvents in the air of beauty salons, the highest value found was Isopropyl alcohol 511.85 ppb followed by butyl acetate, toluene, acetone, xylene, ethyl benzene, styrene, and chlorobenzene. A logistic regression analysis was performed as follows: the point of each factor was the dependent variable while sex, age, drinking, smoking, educational level, work experience, hairdresser's license, and organic solvents were the independent variables. Statistically significant difference (p<0.05) was shown in the hairdresser's license among Factor 1 and in Xylene among Factor 2; however, difference was not shown in the other variables.

• Analytical Science and Technology
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• v.6 no.4
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• pp.383-390
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• 1993

Retention behaviors of aliphatic and aromatic compounds were investigated with Van der Waals volume which represented the molecular size. The organic solvents, methanol, acetonitrile and tetrahydrofuran, were mixed with water at various ratio, respectively. The selectivity of organic solvents were tested by change of column temperature. The capacity factor was increased linearly according to the enlargement of molecular size. Therefore, Van der Waals volume was useful to predict the elution of organic molecules in reversed-phase column. The order of elution capacity of solvents was methanol

• Journal of Environmental Science International
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• v.16 no.1
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• pp.39-44
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• 2007

This study was conducted to investigate the contents of residual solvents and mineral components(11 kinds) in ginseng extracts with different extracting conditions(5 types) and commercial ginseng extract products(domestic, imported). Fine root was extracted with solution having various ethanol concentration after hexane treatment. Among 5 type extracts, residual solvent(hexane) was detected ginseng extracts treated ethanol mixed with hexane. But extracts that dried after soaked in hexane wasn't detected hexane. Mineral components(Al, Mn, Fe, Cu and Zn) were detected in fine root and 5 types of extracts. The contents of mineral components between fine root and extracts with various extracting conditions were similar, however, extracts that dried after soaked in hexane showed the lower amount in Al, Fe, Pb than the others. In comparison with commercial ginseng ex-tract products(domestic, imported), the distribution pattern of mineral was similar but the contents were a little different.

• Bulletin of the Korean Chemical Society
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• v.34 no.1
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• pp.211-220
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• 2013

The characteristic fluorescence properties of quercetin (QCT) and apigenin (API) were studied in various $CH_3OH-H_2O$ and $CH_3CN-H_2O$ mixed solvents. The structure of QCT is completely planar. API is not planar at the ground state but becomes nearly planar at the excited state. If the molecules are excited to the $S_1$ state in organic solvents, QCT exhibits no fluorescence due to excited state intramolecular proton transfer (ESIPT) between the -OH and the carbonyl oxygen, but API shows significant fluorescence because ESIPT occurs slowly. If the molecules are excited to the $S_2$ state, both QCT and API exhibit strong $S_2{\rightarrow}S_o$ emission without any dual fluorescence. As the $H_2O$ composition of both solvents increases, the fluorescence intensity decreases rapidly due to the intermolecular hydrogen bonding interaction. The theoretical calculation further supports these results. The change in fluorescence properties as a function of the solvatochromic parameters was also studied.

• Journal of Applied Biological Chemistry
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• v.57 no.3
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• pp.197-203
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• 2014

Various parameters such as solvent selection, concentration, solid/liquid ratio, soaking time, temperature, stationary, shaking conditions, and repeated extractions were investigated in order to determine the optimum extraction conditions of ${\beta}$-glucosidase from bagasse fermented by mixed culture of Aspergillus niger NRC 7A and Aspergillus oryzae NRRL 447. Among various solvents tested, non ionic detergents gave the best results than the inorganic or organic salt solutions and distilled water. The optimum conditions for extraction of ${\beta}$-glucosidase were 30 min soaking time at $40^{\circ}C$ under shaking condition at 150 rpm, with solid/liquid ratio 1:15 (w/v), which yielded $2882.74{\pm}95.52U/g$ fermented culture (g fc) of enzyme activity. With repeated washes under the above optimum conditions, the results showed that enzyme extracted in the $1^{st}$ and $2^{nd}$ washes represents about 90% of the total activity.

• The Journal of Natural Sciences
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• v.9 no.1
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• pp.169-175
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• 1997

In this study, it was investigated about dyeability, light-fastness, wash-fastness and tensile strength in PET fiber using the effective carrier solvent such as benzyl alcohol, benzaldehyde and acetophenone. As a results, dyeability in mixed solvent was better than that of single solvent. And dyeability in mixed solvents of benzyl aldehyde and acetophenone was of them. But effective carrier action was resulted in decrease of properties such as light-fastness and tensile strength of PET fiber after dyeing.

• Journal of the Korean Chemical Society
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• v.35 no.5
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• pp.443-451
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• 1991

The solvation numbers of some ions in water and of KCl in mixed solvent systems were measured using the conductometric method. Stoke's radii of ions in solution were calibrated by the Nightingale method and the solvation numbers of ions in mixed solvents were deduced by simple assumptions. The deduced solvation numbers of each solvent reasonably go with its selective properties of solvation. From the isosolvation point of ions, the selective properties of ionic solvation were discussed.

• Journal of Korean Society of Forest Science
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• v.110 no.3
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• pp.431-439
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• 2021

The present study evaluated the antioxidant activity, skin wrinkle reduction, and whitening activity of Pinus koraiensiscone scale extracts made with three different solvents (ethanol, supercritical fluid, and a mixture of both). Total polyphenol content was 11.03 mg/g GAE in the supercritical fluid extractand 33.79 mg/g GAE in the 70% ethanol extract. Electron donating ability of 1,000 ㎍/mL extract was 13.60% in the supercritical fluid extract, 91.37% in 70% ethanol extract, and 71.62% in mixed solvent extract. SOD-like activities in 100 ㎍/mL extract using supercritical fluid, 70% ethanol, and mixed solvents were 16.49%, 21.84%, and 10.7%, respectively. The ABTS⁺ radical scavenging activities of 1,000 ㎍/mL extract were 38.19%, 80.23%, and 78.72%for supercritical fluid extract, 70% ethanol extract, and mixed solvent extract, respectively. Tyrosinase inhibitory activities in 1,000 ㎍/mL extract were 24.54%, 36.55%, and 15.23% for supercritical fluid extract, 70% ethanol extract, and mixed solvent extract, respectively. Elastase inhibitory activities in 1,000 ㎍/mL extract were 15.62%, 22.56%, and 26.64% for supercritical fluid extract, 70% ethanol extract, and mixed solvent extract, respectively. Skin astringent activity (81.23% with 5000 ㎍/mL extract) was only detected in the 70% ethanol extract. Supercritical fluid and mixed solvent extracts showed no such activity. Our analysis of Pinus koraiensiscone scale extracts show that the highest aggregate activity was found in the 70% ethanol extract, followed by mixed solvent and supercritical fluid extracts. Therefore, our results oppose the hypothesis stating supercritical extract has the highest total polyphenol content and antioxidant activity.

• Polymer(Korea)
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• v.35 no.5
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• pp.458-466
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• 2011

In the mixed system of supercritical carbon dioxide/organic solvents, poly(vinyl alcohol)(PVA) film of high degree of hydrolysis could be dyed with a dichroic dye of C. I. direct black 22(DB22) and as a result, high durability was obtained. Especially, as a dye dispersant in a supercritical fluid phase, a mixed solvent system of ethylene glycol: dimethyl sulfoxide=4 : 6 weight ratio was investigated. Then the optimum pressure for dyeing could be reduced down to 200 bar. Using this supercritical fluid system, the maximum dyeing appeared as the transmittance of less than 1% and the waste amount was reduced to the level of 1/10. After 500% drawing of this PVA film, both the polarizing efficiency of 94% and the single piece transmittance of 30% were obtained. The limitation of DB22 and further improvements were also discussed.

• Membrane Journal
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• v.23 no.5
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• pp.367-374
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• 2013

In the present study, Pebax-2533 plate membranes were prepared by drying precursor solutions which were obtained by dissolving Pebax-2533 polymer in 1-Propanol/n-Butanol mixed solvents. And then the $CO_2$ and $N_2$ permeation behaviors were tested by using a time-lag system. The prepared Pebax-2533 plate membranes showed a considerable $CO_2/N_2$ separation performance : the $CO_2$ permeability was 130 to 288 barr, and the $CO_2/N_2$ permselectivity was 5-8. The $CO_2$ permeation data obtained by varying feed pressure, permeation temperature, and solvent composition announced that not only the $CO_2$ sorption but also the $CO_2$ diffusion is equally important in the overall $CO_2$ permeation.