• Food Science and Preservation
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• v.14 no.3
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• pp.308-314
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• 2007

To investigate effects of fermentation on volatile components, we analyzed volatile organic compounds of raw and fermented Rhus verniciflua S. bark. A 50%(w/v) sugar solution was used for fermentation. Volatile organic compounds of raw and fermented Rhus verniciflua S. were extracted by the simultaneous steam distillation and extraction(SDE) method, with a mixture of n-pentane and diethylether(1:1, v/v) and analyzed by gas chromatograph-mass spectrometer. A total of 51 and 27 volatile organic compounds were detected in raw and fermented samples, respectively, and were mainly alcohols. Compounds such as ethyl acetate, 2-methyl-3-buten-2-ol, 3-methylbutanal, 1-octen-3-o1, 3-methyl-2-butanone, hexanal and pentanal were detected as the primary compounds in the raw sample. The fermented sample showed sour different volatile compounds, such as ethanol, ethyl acetate, ethyl lactate and 3-methylbutanol. Thus, a number of volatile organic compounds were synthesized after fermentation of Rhus verniciflua S. bark.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.4
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• pp.363-376
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• 2003

In this study, the fugitive emission characteristics of airborne volatile organic compounds from different source categories were evaluated with respect to the concentrations measured in the vicinity of the sources. A total of 22 different sources were investigated, including gasoline storage and filling stations, painting spray booth, laundry, printing officer, textile industries, and a number of environmental sanitary facilities such as landfill, wastewater treatment and incineration plants. The target VOCs included 83 individual compounds, which were determined by adsorption sampling and thermal desorption coupled with GC/MS analysis. Overall, the aliphatic compounds appeared to be the most abundant class of compounds in terms of their concentrations, followed by aromatic, and halogenated hydrocarbons. As a single compound, however, toluene was the most abundant one, explaining 11% of the total VOC concentrations as an average of all the dataset. Among source categories, petroleum associated sources such as gasoline storage/filling stations, and laundry factory were identified as the most significant sources of aliphatic hydrocarbons, while aromatic VOCs were dominantly emitted from the sources handling organic solvents, such as painting booth, printing offices, and textile dyeing processes. However. there was no apparent pattern in terms of the contributions of eath group to the total VOCs concentrations in environmental sanitary facilities. It was also found that the activated carbon adsorption tower installed for the VOC emission control in some facilities do not show any effective performances, which may result in the increased VOC levels in the ambient atmosphere.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.6
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• pp.885-891
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• 2005

The study was carried out to find the effect of freeze drying on the volatile organic components in garlic (Allium sativum L.). The volatile organic compounds from fresh and freeze dried garlic were extracted by simultaneous steam distillation and extraction (SDE) method and identified with GC/MS analysis. A total of 42 and 32 compounds were identified in fresh and freeze-dried garlic, respectively. Sulfur containing compounds in the garlic samples were detected as the major compounds, and alcohols, aldehydes and esters were detected as minor compounds. Diallyl disulfide, diallyl trisulfide, allyl methyl disulfide and ally1 methyl trisulfide were the main sulfur compounds in fresh and freeze dried garlic. The amount of sulfur containing compounds were decreased freeze-drying but methyl propyl trisulide, 3- allylthiopropionic acid, cyclopentyl ethyl sulfide etc. were increased. The others, non- sulfur containing compounds such as ethyl acetate, ethanol, 2-propenol, 2- propenal and hexanal were increased in freeze-dried garlic. Consequently, the total amount of volatile organic compounds in garlic became lower during freeze-drying from 853.42 mg/kg to 802.21 /kg, and the composition of major components were nearly same in fresh and freeze-dried garlic.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.1
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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.

• Journal of Environmental Health Sciences
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• v.30 no.5 s.81
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• pp.487-492
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• 2004

Building materials are composed of very complex chemical compounds, and these indoor building materials discharge very much Volatile Organic Compounds(VOCs). We performed the environmental chamber test to investigate the Total VOCs(TVOCs) emission characteristics and emission factors about chemical and natural coating materials. As the result, we concluded that TVOCs emission are high at initial time and decreased in course of time. Natural paint was low emission level for TVOCs than chemical paint by small chamber test. The TVOCs emission factor-time profile showed a good fit with the results from the measured and predicted value.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.5
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• pp.487-495
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• 2005

Recently, due to the airtightness of buildings or the misuse of building materials, we have been witness SHS (Sick House Syndrome) which can have bad influences on the resident in an existing apartment house as well as newly constructed apartment house start to attract public attention. As a result of this situation, we went to restrict the TVOC (Total Volatile Organic Compound) and formaldehyde. But these guidelines concentrated on only TVOC although TVOC are consist of many individual VOC. Therefore, in this study, we will look about concentration change of VOCs (Volatile Organic Compounds) by using Mock-up test. As result of test, the concentration of four individual VOC (Benzene, Toluene, Ethylbenzene, Styrene) showed quitely low level after 7 days. On the other hand the concentration of Xylene and formaldehyde showed low level after 14 days.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.232-236
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• 2005

In-situ Air Sparging (IAS, AS) is a groundwater remediation technique, in which organic contaminants are volatilized into air as it rises from saturated to vadose soil zone. The purpose of this study was to investigate the effect of environmental conditions on the degradation of VOCs (Volatile Organic Compounds) and $CO_2$ in the unsaturated zone and TPH (Total Petroleum Hydrocarbons) in saturated zone of sandy loam. In the laboratory, diesel (10,000 mg TPH/kg)-contaminated saturated soil. After heating the soil for 36 days, the equilibrium temperature of soil reached to $34.9{\pm}2.7^{\circ}C$ and TPH concentration was reduced to 78.9% of the initial value, Volatilization loss of VOCs in TPH was about 2%, The reduction gradient of $CO_2$ concentration was 0.018/day in air space and 0.0007/day in unsaturated zone.

• Journal of the Korean Wood Science and Technology
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• v.30 no.4
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• pp.80-86
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• 2002

Volatile compounds in three different kinds of crude vinegars obtained from oak (Quercus serrata), bamboo (phyllostachys) and pine (Pinus densiflora) species were analyzed by the solid-phase microextraction (SPME) method. A total of 264 peaks were detected on the chromatograms obtained from the polar (CBP 20) and the nonpolar (CBP 1) columns, which were used for analyzing the volatile compounds in these vinegars. The major volatile compounds identified by using the polar column were 2-butanone, acetic acid, guaiacol, phenol, cresols, 4-ethyl guaiacol, 4-ethyl phenol, and syringol. Using the nonpolar column, seven compounds could be identified: 1,2-dimethoxybenzyl alcohol, 1-hydroxy-2-butanone, 1-(2-furanyl)-1-propane, ethisolide, furfuryl acetate, 1,2-dimethoxybenzene, phenyl acetate. The volatile compounds were classified into five groups: phenols, neutral compounds, organic acids, esters and others. The phenols were the main component and comprised 49~65% of the volatile compounds of these vinegars. In the case of bamboo vinegar, the proportion of the phenols in the volatile compounds was lower than that of the two wood vinegars. However, the proportions of the neutral compounds and the organic acids were higher than those of the wood vinegars. Therefore, it seems that these differences of the proportions of the volatile compounds would make a certain difference of a smoke flavor between the bamboo vinegar and the wood vinegars.

• Journal of Environmental Health Sciences
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• v.43 no.6
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• pp.457-466
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• 2017

Objectives: This study was carried out to investigate the characteristics of volatile organic compounds (VOCs) emitted from sewerage facilities such as a sanitary sewers, outlets, and catch basins. In addition, the dominant malodorous VOCs among the compounds in this study were studied. Methods: Waste gas samples were collected at 27 points in a sanitary sewer in commercial and residental areas. The concentrations of seven volatile organic compounds, including benzene and toluene, in the samples were analyzed by gas chromatograph mass spectrophotometer (GC/MS). Odor concentrations were estimated using the concentration data of the VOCs and each compound's threshold limit value. Results: As a result, it appeared that the average concentration of total observed data for acetaldehyde was 15.98 ppb and benzene 1.87 ppb, toluene 82.31 ppb, ethyl benzene 63.12 ppb, m+p-xylene 15.66 ppb, oxylene 18.73 ppb, and styrene 4.39 ppb. VOC concentrations in the commercial area were higher than those in the residential area. VOC concentrations of waste gas emitted from sewer lines was also higher than those at the outlet and in the catch basins. It was estimated that the main malodorous VOC among the seven VOCs was acetaldehyde. Conclusions: As there is little data on VOC concentrations inside sewer facilities in Korea, these data will be helpful for estimating impact assessment of VOCs and establishing a counter-plan for the abatement of VOCs from sewer facilities in the future.

• Safety and Health at Work
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• v.14 no.2
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• pp.215-221
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• 2023

Background: There is little information about the airborne hazardous agents released during the heat treatment when manufacturing a welding material. This study aimed to evaluate the airborne hazardous agents generated at welding material manufacturing sites through area sampling. Methods: concentration of airborne particles was measured using a scanning mobility particle sizer and optical particle sizer. Total suspended particles (TSP) and respirable dust samples were collected on polyvinyl chloride filters and weighed to measure the mass concentrations. Volatile organic compounds and heavy metals were analyzed using a gas chromatography mass spectrometer and inductively coupled plasma mass spectrometer, respectively. Results: The average mass concentration of TSP was 683.1±677.4 ㎍/m³, with respirable dust accounting for 38.6% of the TSP. The average concentration of the airborne particles less than 10 ㎛ in diameter was 11.2-22.8×10⁴ particles/cm³, and the average number of the particles with a diameter of 10-100 nm was approximately 78-86% of the total measured particles (<10 ㎛). In the case of volatile organic compounds, the heat treatment process concentration was significantly higher (p < 0.05) during combustion than during cooling. The airborne heavy metal concentrations differed depending on the materials used for heat treatment. The content of heavy metals in the airborne particles was approximately 32.6%. Conclusions: Nanoparticle exposure increased as the number of particles in the air around the heat treatment process increases, and the ratio of heavy metals in dust generated after the heat treatment process is high, which may adversely affect workers' health.