• Journal of odor and indoor environment
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• v.17 no.4
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• pp.396-403
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• 2018

In this study, volatile organic compounds (VOCs) emitted from printing industries were analyzed, and an inorganic adsorbent, ${\gamma}-alumina$, was selected for the effective control of the VOC emissions. Printing processes commonly require inks, thinners, and cleaners, and they were mixed organic solvents containing aromatic compounds, ketones, and alcohols. Therefore, toluene, methyl ethyl ketone (MEK), and isopropyl alcohol (IPA) were selected as model compounds for this study. The adsorptive properties using ${\gamma}-alumina$ were determined for the model compounds. Both batch isotherm and continuous flow column tests demonstrated that the adsorption capacity of MEK and IPA was 3~4 times higher than that of toluene. The column test performed at an inlet toluene concentration of 100 ppm showed that an 80% breakthrough for toluene was observed after 3 hours, but both MEK and IPA were continuously adsorbed during the same time period. A numerical model simulated that the ${\gamma}-alumina$ could remove toluene at a loading rate of 0.4 mg/min only for a 4-hour period, which might be too short of a duration for real applications. Consequently, lifetime enhancement for ${\gamma}-alumina$ must be implemented, and ozone oxidation and regeneration would be feasible options.

• Mass Spectrometry Letters
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• v.13 no.4
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• pp.125-132
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• 2022

There are many types of spring blossoms on the Daedeok campus of Chungnam National University (CNU) at the area of 1,600,000 square meters. As an assignment for the class of Analytical Chemistry I for second-year undergraduate students, 2021, flower petals collected from various floral groups (Korean azalea, Korean forsythia, Dilatata lilac, Lilytree, Lily magnolia, and Prunus yedoensis) were analyzed using headspace extraction coupled to gas chromatography-mass spectrometry (HS-GC-MS) to study the aromatic profiles and fragrance compounds of each sample group. Various types of compounds associated with the aroma profiles were detected, including saturated alcohols and aldehydes (ethanol, 1-hexanol, and nonanal), terpenes (limonene, pinene, and ocimene), and aromatic compounds (benzyl alcohol, benzaldehyde). The different contribution of these compounds for each floral type was visualized using statistical tools and classification models based on principal component analysis with high reliability (R² = 0.824, Q² = 0.616). These results showed that HS-GC-MS with statistical analysis is a powerful method to characterize the volatile aromatic profile of biological specimens.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.4 no.1
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• pp.25-29
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• 2000

The present study evaluated the body burden of aromatic VOCs in roadside and underground storekeepers. The Method Detection Limit(MDL) of the analytical system ranged from 0.2 to 0.4$\mu\textrm{g}$/m3 for the target VOCs. The recovery of the sampling system for the compounds was above 80%. For all the target compounds, the breath concentrations of the smokes were similar to or slightly higher than those of the nonsmokers for both the roadside and underground storekeepers. For Ethylbenzene, p-Xylene, and o-Xylene, the breath concentrations of the underground storekeepers were somewhat higher than those of the roadside storekeepers. In contrast, the breath m-xylene concentration of underground storekeepers was similar to that of roadside storekeepers. For both the roadside and underground storekeepers, the breath concentrations prior to and after work were not significantly different.

• Journal of Korean Society for Atmospheric Environment
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• v.14 no.2
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• pp.153-160
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• 1998

The concentrations of volatile organic compounds (VOCs) in the atmosphere were measured from the Yochon Industrial Estate and compared with those from Tongkwangyang and Seoul. The first important phenomenon observed in the air of Yochon was high concentrations of alkenes and in particular, ethylene and propene. For most dominant species, their means and standard deviations were high simultaneously. Concentrations of several major aliphatic species exhibited a similar pattern of diurnal variation, however, with different species combination on each day. Concentrations of several hazardous aromatic species also exhibited a similar pattern of diurnal variation on the same day, which was different from that observed in the diurnal variation of major aliphatic species. It was interpreted that some species were intermittently released from relevant processes. It was also understood that high concentrations and variations of VOC species in Yochon were localized and not related to high average concentrations of ozone in Yochon and Tongkwangyang areas.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.6
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• pp.1053-1058
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• 1998

Volatile flavor compounds in salt fermented big eyed herring were analyzed by vacuum simultaneous distillation solvent extraction/gas chromatography/mass spectrometry/olfactometry and aroma extract dilution anlaysis. A total of 44 volatile compounds were detected by GC/O analysis. Of these, 23 were positively identified, and composed of aldehydes(7), esters(5), ketones(4), sulfur containing compounds (3), aromatic hydrocarbons(2), alcohol(1) and nitrogen containing compound(1). Predominant odorants (Log3FD$\geq$5) in sample were ethyl butanoate(bubble gum /sweet candy-like), 3 methylbutyl butanoate (almond /nutty), 1 octen 3 one(earthy/mushroom like), (E,E) 2,6 nonadienal(roasted wheat/grainy), dimethyl trisulfide(soy sauce /cooked cabbage like), 2 acetylpyrazine(nutty/baked potato like) and unidentified compound(RI=1867, seaweed like).

• Environmental Engineering Research
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• v.16 no.1
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• pp.1-9
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• 2011

During automotive painting, volatile organic compounds (VOCs) associated with the paint solvents are emitted to the atmosphere. Most VOC emissions come from spraying operations via the use of solvent-based paints, as the spraybooth air picks up gaseous solvent compounds and overspray paint materials. The VOCs consist of aromatic and aliphatic hydrocarbons, ketones, esters, alcohols, and glycolethers. Most VOCs (some hydrophilic VOCs are captured and retained in the water.) are captured by an adsorption system and thermally oxidized. In this paper, the processes involved in automotive painting and in VOC control are reviewed. The topics include: painting operations (briefly), the nature of VOCs, VOC-control processes (adsorption, absorption, biological removal, and thermal oxidation) and energy recovery from VOCs using a fuel reformer and a fuel cell, and the beneficial use of paint sludge.

• Journal of Korean Society for Atmospheric Environment
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• v.17 no.3
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• pp.233-240
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• 2001

The composition of volatile organic compounds (VOCs) was anlyzed for major emission sources such as vehicle exhaust, gasoline and diesel vapor, organic solvent vapor, and butane fuel gas. Low carbon-numbered hydrocarbons were found to be the dominant components of gasoline vehicle exhaust. In gasoline evaporative vapor, the predominant constituents were found to be butane and iso-pentane regardless of ambient air temperature. In case of diesel evaporative vapor was similar to those of gasoline evaporative vapor. The composition of organic solvent vapor from painting, ink and petroleum consisted mostly or aromatic compounds such as toluene and m, p, o-xylene. The hydrocarbon fraction of butane fuel gas. which is used by portable bunner, consisted mainly of propane (34%) and butane(70%).

• Safety and Health at Work
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• v.2 no.3
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• pp.210-217
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• 2011

Objectives: The purpose of this study was to measure the concentration of volatile organic compound (VOC)s originated from the chemicals used and/or derived from the original parental chemicals in the photolithography processes of semiconductor manufacturing factories. Methods: A total of four photolithography processes in 4 Fabs at three different semiconductor manufacturing factories in Korea were selected for this study. This study investigated the types of chemicals used and generated during the photolithography process of each Fab, and the concentration levels of VOCs for each Fab. Results: A variety of organic compounds such as ketone, alcohol, and acetate compounds as well as aromatic compounds were used as solvents and developing agents in the processes. Also, the generation of by-products, such as toluene and phenol, was identified through a thermal decomposition experiment performed on a photoresist. The VOC concentration levels in the processes were lower than 5% of the threshold limit value (TLV)s. However, the air contaminated with chemical substances generated during the processes was re-circulated through the ventilation system, thereby affecting the airborne VOC concentrations in the photolithography processes. Conclusion: Tens of organic compounds were being used in the photolithography processes, though the types of chemical used varied with the factory. Also, by-products, such as aromatic compounds, could be generated during photoresist patterning by exposure to light. Although the airborne VOC concentrations resulting from the processes were lower than 5% of the TLVs, employees still could be exposed directly or indirectly to various types of VOCs.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.2
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• pp.222-228
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• 1997

Toha-jeot, a traditional salt-fermented seafood in Korea, was purchased on the market in order to analyze the flavor compounds. Volatile flavor compounds in unfermented and fermented Toha-jeot were compared by vacuum simultaneous steam distillation-solvent extraction/gas chromatography/mass spectrometry. A total of 104 volatile flavor compounds were detected in both samples. Of these, 66 were positively identified, composed of aldehydes(14), ketones(8), alcohols(30), terpenes(20), sulfur-containing compounds(10), aromatic compounds (6), esters(12) and miscellaneous compounds(8). Levels of several other compounds such as aldehydes, terpenes, sulfur-containing compounds and esters decreased with fermentation time, whereas alcohols, ketone and aromatic compounds increased. Particularly, levels of alcohols in fermented Toha-jeot was 21 times higher than those of unfermented one. Major volatile flavor compounds in both samples were composed of terpenes, sulfur-containing compounds, esters and ethanol.

• Journal of Life Science
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• v.16 no.7 s.80
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• pp.1243-1249
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• 2006

Volatile flavor compounds in commercial crab-like flavorants were compared by mean of solid phase microextraction(SPME) and liquid continuous extraction (LLCE)/GC/MSD methods. A total of 86 volatile flavor compounds were detected. Of these, 71 were positively identified consisting mainly of sulfur-containing compounds (13), aldehydes (3), ketones (2), esters (26), alcohols (5), aromatic compounds (3), terpenes (8), acids (2) and miscellaneous compounds (9). SPME method was more effective than LLCE method in detection of volatile components in commercial crab-like flavorants. Eight S-, N-containing compounds such as dimethyl sulfide, dimethyl disulfide, dipropyl disulfide, 3-(methylthio)propyl acetate, 3-(methylthio) propanal, 3-(methylthio) propanol, 2-methyl-3-(methylthio) pyrazine and 2-methyl-5-(methylthio) pyrazine, 8 esters such as styrallyl acetate, ethyl acetate, isoamyl acetate, benzyl acetate, ethyl pentanoate, butyl pentanoate, isoamyl pentanoate and furfuryl acetate were considered as major components in crab-like flavorants.