• 한국철도학회:학술대회논문집
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• 한국철도학회 2002년도 추계학술대회 논문집(II)
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• pp.943-947
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• 2002

Volatile Organic Compounds(VOCs) contribute to the formation of ozone and PAN which are injurious to health through complex photochemical reactions. Growing consumption of fossil fuels results in significant emission of VOCs and other air pollutants into the atmosphere. This study was carried out to evaluate of Volatile Organic Compounds(VOCs) concentrations in Kumi industrial complex. Ambient air sampling was determined at five sites from August to September in 2002. The Volatile Organic Compounds samples were collected using the silicocan canisters, and were determined by GC/MS which connected preconcentrator system. The Kumi industrial complex of VOCs concentrations were generally similar with Yeochun's but some of VOCs concentrations of Kumi were higher than Yeochun industrial complex's. Also the industrial area was higher than downtown and residential district.

• 한국입자에어로졸학회지
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• 제7권1호
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• pp.1-8
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• 2011

In this study, the formation of nanoparticles by a reaction of ozone with the volatile organic compounds(VOCs) emitted from a commercial home cleaner liquid was investigated using a $1-m^3$ reaction chamber($1{\times}1{\times}1m$). The home cleaner liquid was found to contain many VOCs, particularly terpenes. Some of these VOCs are known to readily react with ozone, forming indoor secondary pollutants. The correlation of particle concentration and reacted ozone concentration was examined with injections of three different ozone concentrations; 50, 100 and 200 ppb. The secondary nanoparticles were formed faster, with their numbers and mass concentrations becoming higher on increasing the concentration of ozone injected.

• 한국식품영양과학회지
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• 제27권1호
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• pp.16-23
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• 1998

Effect of Fermentation temperature on the changes of chemical components in Kakudgi during fermentation was investigated by measuring free sugar, organic acid and volatile compounds up to 57 days at several temperatures. The mannitol was increased in palatable period in contrast with those of other free sugars. The higher the initial fermentation temperature was and the longer the initial fermentation time at 2$0^{\circ}C$ was, the faster the second increasing period was and the less the initial contents was. Lactic acid was increased 6~31 times from a little amount at the initial period. The higher the initial fermentation temperature was and the more the increasing content was. But malic acid which was abundant(55.1% of total nonvolatile organic acid) in the initial fermentation period was remarkably decreased in the palatable period. The change of the sulfides among the volatile compounds was remarkable. Methyl allyl sulfide which was a little in the initial fermentation period was remarkably increased in the final fermentation period, and the correlation coefficients between the content of methyl allyl sulfide and aroma in sensory evaluation were high. It could be suggested that the fermentation temperature should be set to 4$^{\circ}C$ after fermentating at 2$0^{\circ}C$ for 36 hours in the view point of keeping the Kakdugi taste and quality well because of high content of free sugar and nonvolatile organic acids.

• 한국재료학회지
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• 제30권10호
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• pp.515-521
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• 2020

Organic-inorganic hybrid perovskite nanocrystals have attracted a lot of attention owing to their excellent optical properties such as high absorption coefficient, high diffusion length, and photoluminescence quantum yield in optoelectronic applications. Despite the many advantages of optoelectronic materials, understanding on how these materials interact with their environments is still lacking. In this study, the fluorescence properties of methylammonium lead bromide (CH₃NH₃PbBr₃, MAPbBr₃) nanoparticles are investigated for the detection of volatile organic compounds (VOCs) and aliphatic amines (monoethylamine, diethylamine, and trimethylamine). In particular, colloidal MAPbBr₃ nanoparticles demonstrate a high selectivity in response to diethylamine, in which a significant photoluminescence (PL) quenching (~ 100 %) is observed at a concentration of 100 ppm. This selectivity to the aliphatic amines may originate from the relative size of the amine molecules that must be accommodated in the perovskite crystals structure with a narrow range of tolerance factor. Sensitive PL response of MAPbBr₃ nanocrystals suggests a simple and effective strategy for colorimetric and fluorescence sensing of aliphatic amines in organic solution phase.

• 한국염색가공학회지
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• 제33권3호
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• pp.153-160
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• 2021

In this study, composite materials were prepared by varying the content of glass fiber and bamboo fiber in PP/glass fiber/bamboo fiber. Experiments were conducted to confirm the mechanical properties(tensile, impact and burst strength) and volatile organic compound content of the bamboo fiber composite prepared under these conditions. An improvement in the main properties was observed at a fiber content of 30wt%. When the fiber fraction was increased above 30wt%, the mechanical properties tended to decrease due to the agglomeration of fibers at higher load fractions. In addition, the content of volatile organic compounds increased as the content of bamboo fibers increased, which is thought to be due to the volatile organic compounds generated during the manufacturing process of the composite material being present in the composite material without escaping from the pores of the bamboo fibers and volatilizing at a certain temperature. As a result of confirming the physical properties of the composite, it is considered that the optimal mixing condition is 30wt% of bamboo fiber for the composite produced by varying the amount of bamboo fiber composite. In the future, it is thought that follow-up experiments to confirm and improve the pre-treatment conditions for reducing the content of volatile organic compounds in the manufactured composite material are possible.

• 한국식품영양과학회지
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• 제34권6호
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• pp.885-891
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• 2005

SDE추출방법 과 GC/MS로 분석에 의하여 생마늘과 동결 건조마늘의 휘발성 유기성분을 비교하였다. 생마늘과 동결 건조마늘에서 각각 42종, 32종의 화합물이 확인되었으며 , 대부분이 황화합물이었고 alcohol류, aldehyde류, ester류도 확인되었다. Diallyl disulfide, diallyl trisulfide, allyl methyl disulfide, allyl methyl trisulfide는 생마늘과 동결건조마늘 에서 확인된 주요 황화합물이었다. 3-Methyl pyridine, 2-methyl-4-pentenal, 2,3,3-trimethyl-1,4=pentadiene, methional등 생마늘에서 확인된 화합물은 동결건조마늘에서 소실되었고 propanethiol, 2-ethyl-3-butenal, acetic acid 등은 동결건조마늘에서 확인되었으며, 전체적인 휘발성 유기성분의 총량에는 영향을 미치지 않는 수준이었다. 동결건조에 의 하여 마늘의 주요 휘발성 유기성분 중 diallyl disulfide, diallyl trisulfide, allyl methyl disulfide, allyl methyl trisulfide, diallyl sulfide,3-vinyl-4H-1,2-dithiin 등 대부분의 황화합물 함량이 감소하였으며 methyl propyl trisulfide, 3- allylthiopropionic acid, cyclopentyl ethyl sulfide 등은 증가하였다. 그 외 ethyl acetate, ethanol,2-propenol, 2-propenal, hexanal 등의 휘발성 유기성분이 증가하는 것을 확인하였다.

• 분석과학
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• 제7권1호
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• pp.125-132
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• 1994

김치의 향미는 당, 유기산, 유리아미노산 및 휘발성 향기성분들의 독특한 조합에 의한 것이며, 휘발성 향기성분은 함황화합물, 알코올류, 휘발성 유기산 및 터핀유 등 여러 가지 극성 및 비극성 성분들이 매우 복잡하게 혼합되어 있다. 김치 휘발성 향기성분의 분석조건을 검토한 결과 추출 분리에는 연속식 추출장치보다 dynamic headspace concentration법이 효율적이었고 GC에 의한 분석에는 5% phenyl methyl polysiloxane 컬럼에 의한 분리가 우수하였다.

• KSBB Journal
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• 제29권5호
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• pp.392-398
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• 2014

It was confirmed that malodor connected with an air-conditioner in an automobile is caused by microbial volatile organic compounds (MVOCs) produced by microorganisms and through microorganisms coexisting with each other to form a biofilm on the evaporator surface. A bacterium, Methylobacterium aquaticum, can form a biofilm on the evaporator surface. The biofilm was composed of 45.79% C (Carbon), 42.36% O (Oxygen), 1.85% Na (Sodium), 5.42% Al (Aluminum), 1.39% P (Phosphorus), 0.74% Cl (Chlorine) and 2.45% K (Potassium). This result matches the composition of the biofilm formed on the surface of the used evaporator. It was determined that sulfur compounds (Hydrogen sulfide, Dimethyl sulfide) and organic acids (n-Butyric acid, n-Valeric acid, iso-Valeric acid) in the air which was blown into the automobile were generated by Methylobacterium aquaticum and Aspergillus versicolor, respectively. On the other hand, volatile organic compounds (Toluene, Xylene, 2-Ethylhexanol, 2-Phenyl- 2-propanol, Ethylbenzene) were not found. It is estimated that the reason is due to the low concentration of generated MVOCs or is caused by the change of some MVOCs depending on the nutrients (medium).

• 미생물학회지
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• 제48권4호
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• pp.305-308
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• 2012

본 연구는 편백나무 건조 중 발생하는 휘발성 유기화합물로 구성된 응축수에 대해 항진균 및 항산화 활성을 평가하였다. 응축수는 hexane과 ethyl acetate로 각각 추출하였으며 추출액의 농도 100-500 mg/L에서 피부사상균에 대한 항진균 활성을 측정하였다. 추출액 농도가 증가할수록 항진균 효과도 증가하였으며 500 mg/L에서는 모든 피부사상균에 대해 높은 항진균 활성을 나타냈다. 추출용매에 따라서는 hexane으로 추출하였을 경우 높은 활성을 나타냈으며, 특히 Trichophyton rubrum에 대한 항진균 활성이 높았다. 항산화 활성을 측정한 결과 25 mg/L 이상의 농도에서는 90% 이상의 항산화 활성을 나타냈으며 추출용매에 따른 차이는 거의 없었다. 하지만 25 mg/L 이하의 농도에서는 hexane 추출물에서 높은 항산화 활성을 나타냈다. 각각의 추출물 구성성분을 분석한 결과 hexane 추출물의 주요 구성성분은 torreyol, alpha-cadinol, tau-cadinol이며, ethyl acetate 추출물의 주요 구성성분은 alpha-amorphene, alpha-cadinol, gamma-cadinene으로 나타났다.

• 한국식품영양과학회지
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• 제24권2호
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• pp.219-227
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• 1995

Natto is a Japanese tradiational food made from whole soybeans by the fermentation of Bacillus natto. This study was attempted to improve the taste of Natto, garlic(2%) and red pepper oleoresin(0.2%) were added. Conventional Natto(N-1), garlic Natto(N-2), red pepper oleoresin Natto(N-3), garlic and red pepper oleoresin Natto(N-4) were prepared. Volatile flavor components, fatty acid, organic acid, pH and titratable acdity in all samples were investigated. The experimental results revealed the presence of 62 volatile components in conventional Natto. Among there, the major flavor compounds were identified to be 2, 5-dimethylpyrazine, trimethyl-pyrazine, 2, 6-bis91, 1-dimethylethyl) phenol. Seventy-one volatile compounds were detected in N-2, and major compounds were identified to be methyl-2-propenyl disulfide, 2, 6-bis(1, 1-dimethylethyl)phenol and 2, 5-dimethylpyrazine. The amounts of volatile compounds, 2-methyoxyphenol and 1, 2-benzenedicarboxylic acid increased by addition of garlic, where as, 1,2 -propanediol, 1-hexanol and 2, 5-dimethylpyrazine decreased. The compounds, 4, 5-dihydroxy-5-propyl-1H-pyrazole, 1, 1, 3-trimethylcyclopentane were identified in N-3. The compounds, such as trimethylpyrazine, 3-ethyl-2,5-dimethylpyrazine increased by addition of red pepper oleoresin, whereas 1,2-propanediol, 1-hexanol and 2,5-dimethylpyrazine decreased. Fatty acid compositions were mainly consisted of linoleic acid(43.66~55.89%) and followed by oleic, palmitic, linolenic, stearic, arachidic, myristic acid. The organic acids we4re identified to be citric(28.2~30.6), acetic(50.0~73.3) and pyroglutamic acid(2.1~3.7).