• Applied Biological Chemistry
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• v.42 no.3
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• pp.210-217
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• 1999

To detect the toxic relevant components, asarone, coumarin and thujone, in the 87 medicinal plants used in brewing a Korean traditional folk wine, their 20% ethanol extracts were prepared and purified by a SPE(solid phase extraction) method. The toxic components in the purified extracts were identified by GC-FID and GC/MS analysis. On analyses, asarone was detected in 6 species, Acorus gramineus Solander, Acorus asiaticus Nakai, Angelia gigus Nakai, Santalum album, etc.; coumarin in 22 species, Anethum graveolens, Foeniculum vulgare Gaertner, Lithosperum erythrorhizon Siebold et Zuccarinii, etc.; thujone in 24 species, Achyranthes japonica Nakai, Amomum xanthiodes Wallich, Artemisia asiatia Nakai, seed of Cannabis sativa L., Caragana sinica R., Chrysanthemum morifolium Ramat, Codonopsis lanceolata Bentham et flooker, Foeniculum vulgare Gaertner, etc.

• Journal of the Korean Society of Tobacco Science
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• v.27 no.1 s.53
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• pp.100-106
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• 2005

To obtain the optimum condition for analysis of 10 alkaloids in tobacco leaves, such as nicotine, nornicotine, anatabine, anabasine, myosmine, cotinine, 2,3'-dipyridyl, $\beta-nicotyrine,\;\beta-nornicotyrine\;and\;\beta-formylnornicotin$, 5 types of extraction method were investigated by GC-FID and GC/MS. The optimum condition of alkaloid extraction was achieved by using methanol:dichloromethane(1:3, v/v) after NaOH treatment. The use of mass selective detector (MSD) provided unambiguous nicotine related alkaloid analysis. Alkaloids in various tobacco leaves were extracted with the optimum extraction condition and quantified by GC/MS/SIM mode. Compared with concentrations of alkaloids among the various tobacco leaves, the concentration of alkaloids was generally in the order burley > flue-cured > oriental tobacco. In flue-cured tobacco leaves, the order of concentration of alkaloids was nicotine > anatabine > nornicotine > $\beta-nicotyrine\;>\;\beta-formylnornicotine\; >\;myosmine\;>\;2,3'-dipyridyl\;>\;cotinine\;>\;anabasine\;>\;\beta-nornicotyrine$. However, in the case of burley and oriental tobacco leaves, the concentration of nornicotine was higher than that of anatabine.

• Journal of Korean Society for Atmospheric Environment
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• v.12 no.3
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• pp.341-350
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• 1996

We determined 6 polycyclic aromatic hydrocarbons (PAHs) fluranthene, pyrene, benz(a)anthracene, chrysene, benzo(a)pyrene, dibenzo(a,h)anthracene). A total of 129 samples has been collected from September 1990 to September 1994 on 2 different types of filters (quartz fiber filter, glass fiber filter) by a PM-10 high volume air sampler at the Kyung Hee University-Suwon campus. The organic components in the PM-10 were extracted by an ultrasonication process with benzene:ethanol(4:1, v/v) prior to the analysis by using a GC/FID. We had also investigated the decaying quantity of 6PAHs at the room temperature. For example, chrysene was decayed by 56.7% after 4 days and benzo(a)anthracene by 84.2% after 30 days. All of PAHs were almost completely decayed after a year. We extensively estimated the decay rates by regression analyses for existing 18 raw data sets. Based on the decay rate constants $(\beta)$, pyrene was rapidly decayed by 19.0 $\times 10^{-2}$/day; on the other hand, dibenzo(a,h)anthracene slowly by 0.7 $\times 10^{-2}$/day. Applying the decay rates of PAHs on stored and dated samples, we could reasonably determine annual and seasonal concentration average of PAHs in particulate matters smaller than 10 $\mu$m.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1011-1020
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• 2001

Volatile organic components from onions stored in the different decay conditions were extracted by SDE apparatus and analyzed by GC-FID and GC/MS. Components of 115, 143, 123 and 137 were identified in fresh onions, decayed onions without heating, half-decayed and complete-decayed onions after heating, respectively. These components included esters, aldehydes, ketones, alcohols and sulfur-containing compounds. Dimethyl trisulfide, dimethyl disulfide, dipropyl trisulfide and 3,5-diethyl-1,2,4-trithiolane were the main sulfur-containing components in fresh onions and decayed onions without heating. As spoilage of onions, the concentrations of sulfur-containing components of volatile extracts significantly decreased. Apart from sulfur-containing components, volatile organic components in half-decayed and complete-decayed onions after heating were mainly composed of esters, aldehydes, ketones and alcohols. Ketones of volatiles in complete-decayed onions after heating were high relatively.

• Korean Journal of Environmental Agriculture
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• v.18 no.3
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• pp.221-228
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• 1999

This study was carried out to extract the natural antioxidants from Bovine bile and to investigate their effects on various antioxidant activities. It also characterized the patterns of antioxidants by GC/FID and GC/MS. The antioxidative activities and chemical structure of the antioxidant were elucidated by examining the effects of biological activity and the analysis of GC/MS. The antioxidant materials extracted from bovine bile were isolated and purified by silica gel column chromatography and TLC. It was confirmed that there were effects of antioxidants such as Xanthine Oxidase(XO) and Glutathione-S-Transferase(GSH-T) on antioxidative activities. When they were compared with BHT, bile extracts showed the relative effects of 51.2% on the antioxidant activity, the inhibition effects of 48.3% on XO activity, and the synergism effects of 85.7% on the GSH-T activity. According to the results of investigation at neuron cell of mouse, the rate of cell activity in the treatment of 6mM glutathione was 96%, While it in the treatment of 140mg of bile extract was 78%. Based on the TLC analysis of EtOAc extracts from the Bovine bile, the antioxidant activity appeared at $R_f$ value, 0.72. These results suggested that the antioxidant may be coprostan 3-ol.

• Analytical Science and Technology
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• v.19 no.6
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• pp.553-558
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• 2006

In this study, an attempt was made to measure uncertainties involved in the VOC analysis for the VOC working standards prepared by a dilution technique using Tedlar bags. For this purpose, VOC standard gases of benzene, toluene, xylene, and styrene were prepared at four different concentrations (4, 8, 20, and 40 ppb). These standard samples were then loaded on to the GC system equipped with air server/thermal desorption (AS/TD) system. Each of these four standard concentrations was analyzed individually to derive their respective calibration results. These calibration data sets were then compared across four different compounds. According to this comparison, differences in calibration patterns were moderately insignificant within the selected concentration range of 4~40 ppb. It was also observed that the loss of styrene standard was fairly high compared to other VOCs investigated simultaneously. The results of our study suggest that the analytical uncertainty associated with the preparation of VOC starndard gas using a dilution technique can be assessed in a fairly reasonable manner for samples with a narrow concentration range.

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.1
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• pp.77-87
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• 2014

In this study, an experimental approach to measure a suite of low weight hydrocarbons was investigated with an emphasis on ethylene (EL) along with many others (ethane (EA), propane (PA), propylene (PL), n-butane (BA), acetylene (AL), methyl acetylene (ML)). Their concentrations were quantified using GC-FID system equipped with thermal desorption (TD) system. The TD-based analysis was conducted using both Link Tube/Thermal Desorber (LT/TD) method and Modified Injection through a Thermal Desorption (MITD) method. The results of these analyses were evaluated in a number of respects. The system allowed the detection of all compounds except methane with the mean response factor (RF) of 10.28 (EA) to 11.94 (PL). The method detection limits of target compounds were seen in the range of 0.027 (ML) to 0.146 ng (BA). The emission flux of some environmental samples (fruits), when measured using a small flux chamber system, fell in the range of 0.14 (AL: Kiwi) to $181ng{\cdot}g^{-1}{\cdot}hr^{-1}$ (EL: Apple Peel). The results of this study confirm that the experimental approach developed in this study allows to accurately measure emissions of low weight hydrocarbons (LWHC) like ethylene from various natural and man-made source processes.

• Preventive Nutrition and Food Science
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• v.3 no.4
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• pp.339-343
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• 1998

Gamma-irradiated chicken at dose levels of 0.1 to 10 kGy was subjected to detection of radiation-induced hydrocarbons whether irradiated or not. The hydrocarbons extracted from chicken fat were separated by florishil column chromatography and identified with GC-FID and GC/MS methods. Eight kinds of hydrocarbons were identified from irradiated chicken, among which 1, 7-hexadecadiene and 8-heptadencene were detected as major compounds , Remarkably radiation-induced hydrocarbons in irradiated chiken were detected at 0.5kGy and over. The concentration of radiation-induced hydrocarbons was relatively constant during 16 weeks.

• Analytical Science and Technology
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• v.33 no.2
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• pp.98-107
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• 2020

Methamphetamine (MA) is currently the most abused illicit drug in Korea. MA is produced by chemical synthesis, and the final target drug that is produced contains small amounts of the precursor chemicals, intermediates, and by-products. To identify and quantify these trace compounds in MA seizures, a practical and feasible approach for conducting chromatographic fingerprinting with a suite of traditional chemometric methods and recently introduced machine learning approaches was examined. This was achieved using gas chromatography (GC) coupled with a flame ionization detector (FID) and mass spectrometry (MS). Following appropriate examination of all the peaks in 71 samples, 166 impurities were selected as the characteristic components. Unsupervised (principal component analysis (PCA), hierarchical cluster analysis (HCA), and K-means clustering) and supervised (partial least squares-discriminant analysis (PLS-DA), orthogonal partial least squares-discriminant analysis (OPLS-DA), support vector machines (SVM), and deep neural network (DNN) with Keras) chemometric techniques were employed for classifying the 71 MA seizures. The results of the PCA, HCA, K-means clustering, PLS-DA, OPLS-DA, SVM, and DNN methods for quality evaluation were in good agreement. However, the tested MA seizures possessed distinct features, such as chirality, cutting agents, and boiling points. The study indicated that the established qualitative and semi-quantitative methods will be practical and useful analytical tools for characterizing trace compounds in illicit MA seizures. Moreover, they will provide a statistical basis for identifying the synthesis route, sources of supply, trafficking routes, and connections between seizures, which will support drug law enforcement agencies in their effort to eliminate organized MA crime.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1244-1250
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• 2000

A method for simultaneous quantitative determination of plasticizers such as diethyl phthalate(DEP), di-n-propyl phthalate(DprP), di-n-butyl phthalate(DBP), di-n-pentyl phthalate(DPP), butylbenzyl phthalate(BBP), di-(2-ethylhexyl) phthalate(DEHP), dicyclohexyl phthalate(DCHP) and di-(2-ethylhexyl) adipate(DEHA), which are suspected as endocrine disruptors, in food was studied. A analysis method was optimized for the quantification of plasticizers in Jjambbong, which is a kind of fatty noodle, by using GC/FID. The detection limits of DEP, DprP, DBP, DPP, BBP, DEHP, DCHP and DEHA were 3.5, 5.3, 2.2, 2.2, 7.2, 1.7, 1.9 and 3.0 mg/kg, respectively. Much higher recovery was obtained by extraction with acetone/n-hexane(1:1) rather than hexane solvent system. The recovery of DEP, DprP, DBP, DPP, BBP, DEHP, DCHP and DEHA were 72.7, 85.9, 91.4, 97.1, 100.8, 103.2, 104.3 and 95.8% after 4 time extractions, respectively. The migration of plasticizers from PVC wraps into PVC wrap covered Jjambbong was conducted after shaking(120 rpm) for 30min at room temperature with chosen solvent system. It was found that the migration level of DEHA were 577, 706, 770 mg/kg into Jjambbong, respectively, while the other plasticizers were not observed.