• KSBB Journal
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• 제28권2호
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• pp.115-122
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• 2013

Volatile flavor compounds of Chamaecyparis obtuse essential oil were extracted by simultaneous steam distillation extraction (SDE) and supercritical fluid extraction (SFE) and analyzed by GC-MS. A total of 48 and 50 components were identified in essential oil by SDE and SFE, respectively. Monoterpenes, oxygenated monoterpenes, sesquiterpenes, oxygenated sesquiterpenes, and diterpenes in essential oil by SDE were 37.24, 10.9, 9.61, 0.22, and 0.22%, respectively. In the case of SFE, they were 19.1, 23.3, 22.66, 1.31, and 10.57%, respectively. Antioxidant activities were increased with the increase of essential oil up to $80{\mu}L/mL$, irrespective of extraction method. Especially, when the essential oil concentration extracted by SDE was increased from 20 to $80{\mu}L/mL$, the antioxidant activity was increased from 10.5 to 55.1%. However, over $80{\mu}L/mL$ of essential oil, an equilibrium state was maintained. In the case of essential oil extracted by SFE, it was decreased compared to that of SDE. For the improvement of atopic dermatitis, various cosmetics such as an ato-cide soap, ato-cide spray, and ato-cide lotion containing essential oil extracted by SFE were tested. About over 90% was useful for the improvement of atopic dermatitis after 4 weeks of clinical trial targeting 40 female adults. These results demonstrate that ato-cide soap, ato-cide spray, and ato-cide lotion containing essential oil extracted by SFE could be used in functional cosmetics.

• 생약학회지
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• 제35권4호통권139호
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• pp.288-292
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• 2004

To evaluate the quality of the crude drugs using three kinds of Cinnamomum Cortex (CC), Vietnamese CC (VCC, the stem bark of Cinnamomum obtusifolium), periderm-peeled Chinese CC (PPCC, periderm-peeled stem bark of C. cassia), Chinese CC (CCC, stem bark of C. cassia) and a Cinnamomi Ramulus (CR, the twig of C. cassia), the four essential oils were prepared by steam distillation method. Cinnamaldehdye (CAN) and an unknown substance tentatively named hydroxy-cinnamaldehdye(HCNA) were detected in the four essential oils by gas chromatography-mass spectrometry, the contents of which are significantly different one another. Vietnamese CC had the highest content of HCNA whereas CR had the highest CAN content and the lowest HCNA. Vietnamese CC exhibited the greatest cytotoxic activity against the cancer cell lines, A549, HepG-2, HL-60, P-388, U-937, and KB and CR the lowest cytotoxicity. Contents of CAN and HCNA in CCC and PPCC are positioned between VCC and CR. These results suggest that measurement of HCNA and cytotoxicity may determine the quality of CC and CR.

• 한국재료학회지
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• 제20권11호
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• pp.600-605
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• 2010

In order to meet the requirements of faster speed and higher packing density for devices in the field of semiconductor manufacturing, the development of Cu/Low k device material is explored for use in multi-layer interconnection. SiOC(-H) thin films containing alkylgroup are considered the most promising among all the other low k candidate materials for Cu interconnection, which materials are intended to replace conventional Al wiring. Their promising character is due to their thermal and mechanical properties, which are superior to those of organic materials such as porous $SiO_2$, SiOF, polyimides, and poly (arylene ether). SiOC(-H) thin films containing alkylgroup are generally prepared by PECVD method using trimethoxysilane as precursor. Nano voids in the film originating from the sterichindrance of alkylgroup lower the dielectric constant of the film. In this study, methyltriphenylsilane containing bulky substitute was prepared and characterized by using NMR, single-crystal X-ray, GC-MS, GPC, FT-IR and TGA analyses. Solid-state NMR is utilized to investigate the insoluble samples and the chemical shift of $^{29}Si$. X-ray single crystal results confirm that methyltriphenylsilane is composed of one Si molecule, three phenyl rings and one methyl molecule. When methyltriphenylsilane decomposes, it produces radicals such as phenyl, diphenyl, phenylsilane, diphenylsilane, triphenylsilane, etc. From the analytical data, methyltriphenylsilane was found to be very efficient as a CVD or PECVD precursor.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2003년도 춘계학술대회
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• pp.194-194
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• 2003

The International Agency for Research on Cancer (IARC, 1989) has classified whole diesel exhaust as probably carcinogenic to humans. Diesel exhaust particulate matter (DPM) adsorbs different chemical substances including PAHs and nitroarenes. DPM is emphasized because it is a major component of diesel exhaust, it is suspected of contributing to a health hazard. Diesel exhaust is a complex mixture of carbon particles and associated organics and inorganics, and it is not known what fraction or combination of fractions cause the health effects [cancer effects, noncancer effects (respiratory tract irritation/inflammation and changes in lung function)] that have been observed with exposure to diesel exhaust. In order to identify which chemical classes are responsible for the majority of the observed biological activities, we performed a particular biological/chemical analysis. Respirable particulate matter (PM2.5: <2.5mm) was collected from diesel engine exhaust using a high-volume sampler equipped with a cascade impactor. Particulate oganic matter was extracted by the dichloromethane/sonication method and the crude extract was fractionated according to EPA recommended procedure into seven fractions by acid-base partitioning and silica gel column chromatography. We examined genotoxic potentials of diesel exhaust particulate matter using novel genotoxicity tests, which are rapid, simple and sensitive methods for assessing DNA-damage at the DNA and chromosomal level (comet assay, in vitro MN test and Ames test). Higher genotoxic potency was observed in non polar fractions and several PAHs were detected by GC-MS, such as 1,2,5,6 dibenzanthracene, chrysene, 1,2-benzanthracene, phenanthrene and fluoranthene.

• 한국식품과학회지
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• 제32권4호
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• pp.908-913
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• 2000

사과쥬스 제조 후 대부분 폐기 처분되고 있는 사과박의 이용성을 증대하기 위해 사과박의 유용성분을 분석하고 사과박 추출물의 항산화 활성을 조사하였다. 사과박의 총플라보노이드 함량은 458 mg%, 총페놀 함량은 1048 mg%, 비타민 C함량은 19.8 mg%로 나타났으며 사과박의 식이섬유 함량은 총식이섬유 55.56%, 수용성 식이섬유 14.20%, 불용성 식이섬유41.36%로 나타났다. 사과박의 phenolic acid는 protocatechuic acid가 3.51 mg%로 가장 높은 함량을 나타내었으며 사과박의 flavonoid를 HPLC로 분석하였을때 phloridzin과 quercetin-3-glucoside가 확인되었으며 각각의 함량은 48.87 mg%, 16.22 mg%로 나타났다. 사과박의 각 분획별 항산화능 시험에서 지용성 모델계에서 BHA와 ${\alpha}-tocopherol$보다는 낮지만 ethyl acetate 획분이 높은 항산화능을 나타내었을 뿐만 아니라 쥐 간조직을 기질로한 과산화지질 생성억제 시험에서도 ethyl acetate 획분이 가장 낮은 값을 나타내었다.

• 한국물환경학회지
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• 제24권5호
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• pp.598-602
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• 2008

The Daecheong Reservoir is the largest multi-purpose reservoir in the Keum River basin. This water supply is subject to some of the most serious taste and odor (T&O) problems in the region. The intensity of T&O events increased due to eutrophication during the 1990s. In this study, the temporal occurrence of T&O in raw water from the main Daecheong Reservoir and its regulating reservoir was compared using both an instrumental method (CLSA+GC/MS) and threshold odor number (TON) test from April to December 2006. In addition, biofilms on the submerged macrophytes and rocks were analyzed for two typical T&O causing compounds, Geosmin and 2-MIB. The maximum concentration of Geosmin in the main reservoir was almost two times higher than that in the regulating reservoir. Interestingly, 2-MIB was only detected in water samples from the main reservoir. In the case of T&O causing compounds present in the biofilm on the submerged macrophytes and rocks, the regulating reservoir had lower concentrations compared to those of the main reservoir. It was found that both Geosmin and 2-MIB were detected from the biofilms much earlier than from the water samples. This result suggests that the occurrence of T&O compounds in the biofilms could be used as an early warning indicator of an imminent T&O outbreak in the water body.

• 한국식품조리과학회지
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• 제17권6호
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• pp.565-570
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• 2001

본 연구에서는 쇠비름을 메탄올로 추출하여 식품의 부패나 식중독성을 유발하는 세균과 곰팡이에 대한 추출물의 항균활성을 검토하고 그들의 최소생육저해농도를 결정하였으며 쇠비름 추출물의 구성성분과 함량을 분석하였다. 쇠비름은 특히 P. citreonigrum 균주에 대해 매우 높은 항균효과를 보였고 S aureus, K. pneumoniae에 대해서는 benzoic acid에 상응할 만한 항균효과를 나타내었다. 쇠비름 메탄올 추출물은 200mg/$m\ell$ 농도에서 S. aureus와 P. citreonigrum의 생육을 억제하였고, 250 mg/$m\ell$ 농도에서 K. pneumoniae의 생육을 억제하였으며, 300 mg/$m\ell$ 농도에서 P. aeruginosa와 E. coli의 생육을 억제하였다. 따라서 이들 균주에 의한 식품의 부패 및 식중독이 우려되는 식품의 항균제로서 쇠비름의 사용 가능성을 볼 수 있었다. 쇠비름 메탄올 추출물의 분석결과 전체 147가지 성분이 분석되었으며 acid 및 ester류가 41.06%로 추출물의 가장 많은 부분을 차지하고 있었다. 또한 세균, 곰팡이, 효모와 같은 미생물에 항균활성을 나타내는 것으로 보고되어 있는 2,3-dihydro-benzofuran, 4-hydroxy-3-methoxy- benzoic acid와 4-hydroxy benzeneethanol 등의 성분들이 검출되었다.

• 상하수도학회지
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• 제18권5호
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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.

• 한국재료학회지
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• 제33권7호
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• pp.265-272
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• 2023

In this study, the synthesis of nitrobenzene was carried out using sulfated silica catalyst. The study delved into H₂SO₄/SiO₂ as a solid acid catalyst and the effect of its weight variation, as well as the use of a microwave batch reactor in the synthesis of nitrobenzene. SiO₂ was prepared using the sol-gel method from TEOS precursor. The formed gel was then refluxed with methanol and calcined at a temperature of 600 ℃. SiO₂ with a 200-mesh size was impregnated with 98 % H₂SO₄ by mixing for 1 h. The resulting 33 % (w/w) H₂SO₄/SiO₂ catalyst was separated by centrifugation, dried, and calcined at 600 ℃. The catalyst was then used as a solid acid catalyst in the synthesis of nitrobenzene. The weights of catalyst used were 0.5; 1; and 1.5 grams. The synthesis of nitrobenzene was carried out with a 1:3 ratio of benzene to nitric acid in a microwave batch reactor at 60 ℃ for 5 h. The resulting nitrobenzene liquid was analyzed using GC-MS to determine the selectivity of the catalyst. Likewise, the use of a microwave batch reactor was found to be appropriate and successful for the synthesis of nitrobenzene. The thermal energy produced by the microwave batch reactor was efficient enough to be used for the nitration reaction. Reactivity and selectivity tests demonstrated that 1 g of H₂SO₄/SiO₂ could generate an average benzene conversion of 40.33 %.

• 한국환경농학회지
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• 제33권4호
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• pp.414-418
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• 2014

BACKGROUND: Benzene, toluene, ethylbenzene and xylene (BTEX), which are volatile aromatic hydrocarbons and main constituents of gasoline, are neuro-carcinogenic organic pollutants in soil and groundwater. Korea Ministry of Environment has established the maximum permissible level of BTEX in arable soil to 1, 20, 50 and 15 mg/kg, respectively. METHODS AND RESULTS: To understand an arable soil contamination by BTEX, we collected 92 samples from the arable lands around oil reservoir, and analyzed the BTEX residue using a GC-MS with head-space sampler. A linear correlation between BTEX concentration and peak areas was detected with coefficient correlations in the range of 0.9807-0.9995. The method LOQ of BTEX was 0.002, 0.014, 0.084, and 0.038 mg/kg, respectively. Recoveries of 0.5 mg/kg BTEX were found to be 73.7-96.9%. The precision was reliable since RSD percentage (0.7-7.5%) was below 30, which was the normal percent value. Also, BTEX in all samples were detected under the LOQ. CONCLUSION: These results showed that the investigated arable soils around airport and oil reservoir in Korea were not contaminated by oils.