• Korean Journal of Food Science and Technology
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• v.32 no.2
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• pp.238-245
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• 2000

This study was investigated to compare the changes of flavors in sesame oil with roasting temperature $(110^{\circ}C{\sim}230^{\circ}C)$. In the results of analyzing the volatile flavor compounds of sesame oil with GC and GC/MS, 26 pyrazines, 11 pyridines, 9 thiazoles, 6 furans, 8 pyrroles, 5 phenols, 8 aldehydes, 8 hydrocarbons, 7 alcohols, 2 indoles, 3 ketones, 10 acids, 4 nitriles, 7 esters, and 5 others were isolated, identified, and quantified. The total amount of flavor compounds was increased with roasting temperature. Detected flavors could be devided into top(peak No. $1{\sim}91$), middle$(92{\sim}197)$ and last note$(198{\sim}224)$ by rentention time. The top notes(initial content 19.87 ppm) which contain pyrazines and provide representative roasted flavors were increased significantly with roasting temperature. Initial content of middle note(17.72 ppm) was increased to 36.71 ppm at $170^{\circ}C$, to 95.61 ppm at $220^{\circ}C$, and to 138.62 ppm at $230^{\circ}C$. Last note was almost unchanged up to $170^{\circ}C$ and increased at $190^{\circ}C$, whereas it indicated a tendency to decrease at $230^{\circ}C$. Pyrazines such as methylpyrazine, 2,5-dimethylpyrazine, 2,6-dimethylpyrazine, trimethylpyrazine, 2-ethyl-3,5-dimethylpyrazine which indicate the major components among volatile flavors were increased slightly up to $150^{\circ}C$ and revealed the higher increase than any other components above $170^{\circ}C$. This tendency was also similar to pyridines, thiazoles, and furans. Most of these compounds are assumed to be developed by thermochemical reactions of sesame components by roasting above $170^{\circ}C$. It seemed that a lot of increase in phenols above $210^{\circ}C$ resulted from the production of guaiacol. Acids were almost unchanged up to $190^{\circ}C$, increased at $210^{\circ}C$, and then decreased above $220^{\circ}C$. It seemed to be resulted from pyrolysis of free fatty acids formed from thermal oxidation of oil.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.1
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• pp.145-151
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• 2006

As the concerns about indoor air quality (IAQ) increase in recent years, lots of research works are under way to investigate the influence of volatile organic compounds (VOCs) emitted from building products on the IAQ. One of the regulations for the IAQ is the level of total VOCs (TVOCs) from building products, assuming that the TVOCs are suspected to cause many health problems such as skin irritation, asthma, and allergy. However, the presence of biogenic VOCs, or natural VOCs (NVOCs) is believed to be beneficial to human health. Therefore, this study attempted to investigate chemical species and the NVOCs compositions of solid lumbers from different wood species. It was found that major VOC components were monoterpenes such as $\alpha$-pinene, $\beta$-pinene, d-limonene, camphene, $\alpha$-terpinene, $\gamma$-terpinene etc.

• Journal of Korean Society for Atmospheric Environment
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• v.15 no.1
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• pp.63-69
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• 1999

To offer a general guideline for the quantitative analysis of airborne pollutants, we designed and conducted a comprehensive QA/QC test using two different strategic approaches, namely (1) field-based comparative measurement and (2) laboratory-based comparative analysis. The former task was performed to make meaningful comparison of combined errors occurring from both sampling and analytical techniques in the measurements of such components as: (1) criteria pollutants, (2) volatile organic compounds (VOCs), and (3) particulate matters with the associated metals and ions. The latter task was also conducted to compare various types of bias arising mainly from the laboratory analytical procedures of (1) gaseous standards of VOCs and (2) of aqueous standards of metals and ions. The concentration data derived from each of these two different types of major tasks were evaluated per chemical species categorized as above. While the very details of these studies are to be reported on an individual basis according to the above classification of the project, this paper is presented to provide an overview of the whole project - its aim and direction.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.6
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• pp.759-771
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• 2004

This study analyzed concentrations of volatile organic compounds (VOCs) produced from incineration of plastic wastes at $600^{\circ}C$. The plastic wastes used in this study included polyethyleneterephthlate (PETE), high density polyethylene (HOPE), polyvinyl chloride (PVC), low density polyethylene (LOPE), polypropylene (PP), polystyrene (PS) and other. Plastic wastes were heated from room temperature upto $600^{\circ}C$ providing the compressed air inside of a small-scale electric furnace for 90 minutes and then they were oxidized (incinerated) for 60 minutes at $600^{\circ}C$ maintaining the same air supply. VOCs emitted from the incineration process were sampled using an air sampling pump and Tedlar air bags for 150 minutes and then the components and concentrations of the VOCs were analyzed by a GC-MS. The most prominent chemical structure of the VOCs obtained from the incineration process of the HOPE, LOPE and PP, which include ethylene groups in their main chains, was identified as aliphatic hydrocarbons such as 1-hexene. However, aromatics such as benzene were major chemical structure from the incineration of PETE, PVC and PS which include benzene rings in their main chains. This study estimated the total VOC production from the incineration of the plastic wastes based on the real plastic waste production and the emission factors. 64% and 27% of the total VOC emissions consisted of aliphatic hydrocarbons and aromatics, respectively, which have double bonds within their molecular structure and thus a high ground level ozone formation potential.

• Journal of the Korean Society of Tobacco Science
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• v.24 no.2
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• pp.75-81
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• 2002

This study was performed to investigate the influence of curing conditions on the composition of essential oil during curing process of burley tobacco leaves. The curing conditions were the primed curing in vinyl house (house-curing), air-curing barn (air-curing) and stalk-curing in conventional curing house (stalk-curing). Total 90 compounds are identified from the steam volatile oils of harvest and cured tobacco leaves by GC and GC-MS, respectively. The major components were neophytadiene, hexadecanoic acid, 3,8,13-duvatriene-1,5-diols, oxide-9-methylene-3,13-duvadienols, solanone, megastigma-4,6,8-trien-3-ones, phenylacetaldehyde, $\beta$-phenylethyl alcohol, indole, dihydroactinidiolide and phytol. The amount of alcoholic compounds was decreased more than approximately 50% in cured leaves without regard to the curing conditions. $\beta$-Phenylethyl alcohol and 3,8,13-duvatriene-1,5-diols were decreased more in air curing and stalk curing than in house curing. The amounts of phenylacetaldehyde, solanone, $\beta$-damascone, $\beta$ -damascenone, oxysolanone and megastigma-4,6,8-trien-3-ones as ketonic compounds, dihydroactinidiolide and indole as miscellaneous compounds in air-cured and stalk-cured tobacco leaves were 2 times higher than those in house-cured leaves, while esteric and acidic compounds were not changed largely in content by curing conditions.

• Clean Technology
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• v.10 no.3
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• pp.149-158
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• 2004

Supercritical carbon dioxide is often promoted as an environmentally friendly solvent having useful properties for a wide range of technical and chemical processes. But the limited ability of $CO_2$ to dissolve polar or non-volatile compounds represents a major drawback in many processes, because the key components will often fail to form homogeneous solution under practical conditions. The design of $CO_2$ soluble ($CO_2$-philic) surfactant to aid this process is therefore paramount in these areas, which has advanced the "greening" of demanding yet important applications in dyeing, cleaning of fibers and texiles, polymerization and polymer processing, photoresist removal, electroplating, and chemical synthesis.

• Food Science and Preservation
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• v.6 no.2
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• pp.200-205
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• 1999

This experiment was carried out to search mm reasonable and scientific method to distinguish Korean sesame with Chinese sesame. Sesame samples used in this study were Korean variety cultivated in Chochiwon City of Korea (KvKc), Chinese variety cultivated in Jilin Province of China (CvCc), Chinese variety cultivated in Chochiwon city of Korea (CvKc) and Korean variety cultivated in Jilin Province of China (KvCc). In volatile flavor components analysis, 41 component were identified from KvKc and 39 components from CvCc. Major flavor components were pyrazines and furans. Pyrazines compositions of KvKc and CvCc were 55.4% and 56.8%, respectively while furans compositions of KvKc and CvCc were 27.0% and 20.4%, respectively. Other flavor components pattern showed no difference. When the headspace volatiles of sesame oils were analyzed using Electronic Nose System and the obtained data were interpreted using statistical method of MANOVA and Discriminant analysis, characteristic patterns of sesame oil odors were different from each other according to variety as well as cultivated area. These results suggest that Korean sesame oils may be distinguished from Chinese sesame oils by using Electronic Nose System.

• Bulletin of the Korean Chemical Society
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• v.30 no.5
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• pp.1121-1126
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• 2009

This paper describes a pattern recognition method of Magnoliae flos based on a gas chromatographic/mass spectrometric (GC/MS) analysis of the essential oil components. The botanical drug is mainly comprised of the four magnolia species (M. denudata, M. biondii, M. kobus, and M. liliflora) in Korea, although some other species are also being dealt with the drug. The GC/MS separation of the volatile components, which was extracted by the simultaneous distillation and extraction (SDE), was performed on a carbowax column (supelcowax 10; 30 m{\time}0.25 mm{\time}0.25{\mu}m$) using temperature programming. Variance in the retention times for all peaks of interests was within RSD 2% for repeated analyses (n = 9). Of the 74 essential oil components identified from the magnolia species, approximately 10 major components, which is $\alpha$-pinene, $\beta$-pinene, sabinene, myrcene, d-limonene, eucarlyptol (1,8-cineol), $\gamma$-terpinene, p-cymene, linalool, $\alpha$-terpineol, were commonly present in the four species. For statistical analysis, the original dataset was reduced to the 13 variables by Fisher criterion and factor analysis (FA). The essential oil patterns were processed by means of the multivariate statistical analysis including hierarchical cluster analysis (HCA), principal component analysis (PCA) and discriminant analysis (DA). All samples were divided into four groups with three principal components by PCA and according to the plant origins by HCA. Thirty-three samples (23 training sets and 10 test samples to be assessed) were correctly classified into the four groups predicted by PCA. This method would provide a practical strategy for assessing the authenticity or quality of the well-known herbal drug, Magnoliae flos.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.11a
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• pp.44-63
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• 2000

Situated close to Heathrow Airport, and adjacent to the M4 and M25 Motorways, the site at Axis Park is considered a prime location for business in the UK. In consequnce two of the UK's major property development companies, MEPC and Redrew Homes sought the expertise of Intergeo to remediate the contaminated former industrial site prior to its development. Industrial use of the twenty-six hectare site, started in 1936, when Hawker Aircraft commence aircraft manufacture. In 1963 the Firestone Tyre and Rubber Company purchased part of the site. Ford commenced vehicle production at the site in the mid-1970's and production was continued by Iveco Ford from 1986 to the plant's decommissioning in 1997. Geologically the site is underlain by sand and gravel, deposited in prehistory by the River Thames, with London Clay at around 6m depth. The level of groundwater fluctuates seasonally at around 2.5m depth, moving slowly southwest towards local streams and watercourses. A phased investigation of the site was undertaken, which culminated in the extensive site investigation undertaken by Intergeo in 1998. In total 50 boreholes, 90 probeholes and 60 trial pits were used to investigate the site and around 4000 solid and 1300 liquid samples were tested in the laboratory for chemical substances. The investigations identified total petroleum hydrocarbons in the soil up to 25, 000mg/kg. Diesel oil, with some lubricating oil were the main components. Volatile organic compounds were identified in the groundwater in excess of 10mg/l. Specific substances included trichloromethane, trichloromethane and tetrachloroethene. Both the oil and volatile compounds were widely spread across the site, The specific substances identified could be traced back to industrial processes used at one or other dates in the sites history Slightly elevated levels of toxic metals and polycyclic aromatic hydrocarbons were also identified locally. Prior to remediation of the site and throughout its progress, extensive liaison with the regulatory authorities and the client's professional representatives was required. In addition to meetings, numerous technical documents detailing methods and health and safety issues were required in order to comply with UK environmental and safety legislation. After initially considering a range of options to undertake remediation, the following three main techniques were selected: ex-situ bioremediation of hydrocarbon contaminated soils, skimming of free floating hydrocarbon product from the water surface at wells and excavations and air stripping of volatile organic compounds from groundwater recovered from wells. The achievements were as follows: 1) 350, 000m3 of soil was excavated and 112, 000m3 of sand and gravel was processed to remove gravel and cobble sized particles; 2) 53, 000m3 of hydrocarbon contaminated soil was bioremediated in windrows ; 3) 7000m3 of groundwater was processed by skimming to remove free floating Product; 4) 196, 000m3 of groundwater was Processed by air stripping to remove volatile organic compounds. Only 1000m3 of soil left the site for disposal in licensed waste facilities Given the costs of disposal in the UK, the selected methods represented a considerable cost saving to the Clients. All other soil was engineered back into the ground to a precise geotechnical specification. The following objective levels were achieved across the site 1) By a Risk Based Corrective Action (RBCA) methodology it was demonstrated that soil with less that 1000mg/kg total petroleum hydrocarbons did not pose a hazard to health or water resources and therefore, could remain insitu; 2) Soils destined for the residential areas of the site were remediated to 250mg/kg total petroleum hydrocarbons; in the industrial areas 500mg/kg was proven acceptable. 3) Hydrocarbons in groundwater were remediated to below the Dutch Intervegtion Level of 0.6mg/1; 4) Volatile organic compounds/BTEX group substances were reduced to below the Dutch Intervention Levels; 5) Polycyclic aromatic hydrocarbons and metals were below Inter-departmental Committee for the Redevelopment of Contaminated Land guideline levels for intended enduse. In order to verify the qualify of the work 1500 chemical test results were submitted for the purpose of validation. Quality assurance checks were undertaken by independent consultants and at an independent laboratory selected by Intergeo. Long term monitoring of water quality was undertaken for a period of one year after remediation work had been completed. Both the regulatory authorities and Clients representatives endorsed the quality of remediation now completed at the site. Subsequent to completion of the remediation work Redrew Homes constructed a prestige housing development. The properties at "Belvedere Place" retailed at premium prices. On the MEPC site the Post Office, amongst others, has located a major sorting office for the London area. Exceptionally high standards of remediation, control and documentation were a requirement for the work undertaken here.aken here.

• Analytical Science and Technology
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• v.18 no.6
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• pp.500-510
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• 2005

This study was conducted to investigate the chemical composition of essential oil, absolute and oleoresin isolated from Elsholtzia splendens and their biological activities. Yields of essential oil, absolute and oleoresin extracted from Elsholtzia splendens were 0.28%, 12.45% and 9.95%, respectively. The major component was 2-cyclohexen-1-one in essential oil, methyl linolenate in absolute and 9,12,15-octadecatrienoic acid in oleoresin. Essential oil and oleoresin showed the inhibitory activities in enzyme-dependent, enzyme-independent and autooxidative lipid peroxidation system. $EC_{50}$ values in nuetral red uptake (NRU) assays for the exposure times of 24 h were $46.4{\mu}g/ml$, $681.7{\mu}g/ml$ and $17.6{\mu}g/ml$ in essential oil, absolute and oleoresin, and oleoresins showed the cytotoxic effect at the only high dose. Any mutagenic and antibiotic activity did not show in absolute and oleoresin, but, there were mutagenic and antibiotic activities only when treated with essential oil $500{\mu}g/ml$ above in Ames test. Essential oil and oleoresin might be somewhat effective in prolongating the ciliostasis of rat trachea.