• Title, Summary, Keyword: hydrocarbons

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Detection of Radiation-Induced Hydrocarbons in Green, Black and Oolong Teas

  • Kausar, Tusneen;Lee, Jung-Eun;Noh, Jung-Eun;Kwon, Young-Ju;Kwon, Joong-Ho
    • Preventive Nutrition and Food Science
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    • v.9 no.3
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    • pp.222-226
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    • 2004
  • Hydrocarbons induced by gamma-irradiation of green, black, and oolong teas were analyzed to determine whether the hydrocarbons can be used as markers for detecting post-irradiation of these teas. The samples were irradiated at 0, 2.5, 5, 7.5, and 10 kGy. Detection was attempted by extracting fat from the teas, separation of hydrocarbons with florisil column chromatography, and identification of hydrocarbons by gas chromatography-mass spectroscopy (GC-MS). Concentration of hydrocarbons increased with the irradiation dose. The major hydrocarbons in irradiated green, black, and oolong teas were 1-tetradecence (14:1), pentadecane (15:0), 1,7-hexadecadiene (16:2), 1-hexadecene (16:1), 8-heptadecene (17:1), and heptadecane (17:0). Radiation-induced hydrocarbons in teas were 1,7-hexadecadiene and 8-heptadecene. These compounds were not detected in non-irradiated samples, so the hydrocarbons (16:2, 17:1) can be used as markers for detecting post-irradiation of the teas. Furthermore, detection of hydrocarbons after 12 months storage at room temperature remains a suitable method for identifying irradiated teas.

Detection of Radiation-induced Hydrocarbons and 2-Alkylcyclobutanones from Peanuts

  • Lee, Hae-Jung;Lee, Myung-Yul;Kim, Kyung-Su
    • Preventive Nutrition and Food Science
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    • v.4 no.4
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    • pp.270-275
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    • 1999
  • Radiation-induced hydrocarbons and 2-alkylcyclobutanones are formed from the fatty acids of irradiated fats. Peanuts were irradiated with a dose of 0.1∼10 kGy. The method consists of the extraction of fat from peanuts, separation of hydrocarbons and 2-alkylcyclobutanones with florisil column chromatography and identification of hydrocarbons by the GC/MS method and 2-alkylcyclobutanones by GC/MS/selected ion monitoring (SIM). Concentrations of hydrocarbons and 2-alkylcyclobutanones were linearly increased with the dose levels of radiation. The major hydrocarbons in the irradiated peanut samples were 8-heptadecene and 1,7-hexadecadiene from oleic acid and 6,9-heptadecadiene and 1,7,10-hexadecatriene from linoleic acid. 2-(5'-Tetradecenyl)cyclobutanone, one of 2-alkylcyclobutanones, was the highest amount in the irradiated peanuts. Radiation-induced hydrocarbons in the peanuts were detected at doses of 0.5 kGy and over, and radation-induced 2-alkylcyclobutanones were detected at doses of 1 kGy and over. These compounds were not confirmed in unirradiate peanuts.

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Methodology for removing unreacted low-hydrocarbons in diesel reformate for stable operation of solid oxide fuel cells (안정적인 SOFC 운전을 위한 디젤 개질기 내 미반응 저탄화수소 제거법)

  • Yoon, Sang-Ho;Bae, Joong-Myeon;Lee, Sang-Ho
    • 한국신재생에너지학회:학술대회논문집
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    • pp.773-776
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    • 2009
  • In this paper, new concept of the diesel fuel processing is introduced for the stable operation of solid oxide fuel cells (SOFCs). Heavier hydrocarbons than $CH_4$, such as ethylene, ethane, propane, and etc., induce the carbon deposition on anode of SOFCs. In the reformate of heavy hydrocarbons (diesel, gasoline, kerosene, and JP-8), concentration of ethylene is usually higher than low hydrocarbons such as ethane, propane, and butane. So, removal of low hydrocarbons (over C1-hydrocarbons), especially ethylene, at the reformate gases is important for stable operation of SOFCs. New methodology as named "post-reformer" is introduced for removing the low hydrocarbons at the reformate gas stream. Catalyst of the NECS-PR4 is selected for post-reforming catalyst because the catalyst of NECS-PR4 shows the high selectivity for removing low hydrocarbons and achieving the high reforming efficiency. The diesel reformer and post-reformer are continuously operated for about 200 hours as integrated mode. The reforming performance is not degraded and low hydrocarbons in the diesel reformate are completely removed.

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Analysis of Radiolytically Proudced Hydrocarbons and 2-Alkylcyclobutanones from Irradiated Pinenut (방사선 조사된 잣으로부터 조사 여부를 확인하기 위한 Hydrocarbon류와 2-Alkylcyclobutanone류의 분석)

  • 이해정;김경수
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.30 no.1
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    • pp.37-42
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    • 2001
  • Pinenut was irradiated with the dose of 0.5∼10 kGy. Radiation-induced hydrocarbons and 2-alkylcyclobutanones were extracted from pinenut, separated by florisil column chromatography and identified with GC/MS method. Concentrations of hydrocarbons and 2-alkylcyclobutanones were increased with the increase of irradiation dose and the composition of patty acids in pinenut affected on products detects. The major hydrocarbons in irradiated pinenut were 8-heptadecene and 1,7-hexadecadiene originated ferom oleic acid and 6,9-heptadecadiene and 1, 7, 10-hexadecatriene originated from linoleic acid. 2-(5'-Tetradecenyl) cyclobutanone originated from oleic acid was highest in the irradiated pinenut. Radiation-induced hydrocarbons hydrocarbons and 2-alkylcyclobutanones in pinenut were detected at 0.5 kGy and over, but not detected in the unirradiated samples.

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Quantitative Analysis of Radiation-induced Hydrocarbons in Irradiated Chicken at Various Dose Levels

  • Kim, Eun-Ah;Lee, Hae-Jung;Yang, Jae-Seung;Kim, Kyong-Su
    • 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.

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The Microwave-Assisted Extraction of Fats from Irradiated Meat Products for the Detection of Radiation-Induced Hydrocarbons

  • Kwon, Joong-Ho;Kausar, Tusneem;Lee, Jeong-Eun;Kim, Hyun-Ku;Ahn, Dong-U
    • Food Science and Biotechnology
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    • v.16 no.1
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    • pp.150-153
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    • 2007
  • Hydrocarbons have been successfully used as a chemical marker in order to identify irradiated from non-irradiated foods. The method for determining hydrocarbons consists of extraction of fats, followed by separation of hydrocarbons by florisil column chromatography, and then identification of hydrocarbons by GC/MS. Currently, solvent extraction method for fats has certain limitations with regard to extraction time and solvent consumption. Commercial hams and sausage were irradiated at 0 and 5 kGy, and the efficiency of microwave-assisted extraction (MAE) and conventional solvent extraction (CSE) methods on the extraction of radiation-induced hydrocarbons from the meat products was compared. Significant levels of hydrocarbons, mainly composed of 1,7-hexadecadien, 1,7,10-hexadecatriene, and 6,9-heptadecadiene, were detected in the extracts from irradiated hams and sausages by both CSE and MAE methods. Both methods were acceptable in extracting hydrocarbons from samples, but MAE method required apparently reduced amounts of solvent from 150 (CSE) to 50 mL and reduced extraction time from 23 (CSE) to 5 min.

Analysis of Gas Hydrocarbons by Gas-Liquid Partition Chromatography (Gas Chromatography 에 依한 까스炭化水素의 分析)

  • Chwa-Kyung Sung;Icksam Noh;Jung Yup Kim
    • Journal of the Korean Chemical Society
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    • v.7 no.2
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    • pp.128-132
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    • 1963
  • A study has been made on the applicability of gas-liquid partition chromatography to the qualitative and quantitative analysis of complex mixture of gaseous hydrocarbons. While phthalate columns are widely used for this $purpose^9$, they separates neither saturated hydrocarbons from the unsaturated nor n-butane from isobutene or butene-1, therefore combined columns such as phthalate and dimethylsulfolane have been used for the perfect separation of gaseous hydrocarbons. It is shown by this study, however, that hydrocarbons having $C_1$ through $C_4$ can be separated with a 2-meters tetraethyleneglycol dimethylether column except ethane from ethylene, and trans-from cis-2-butene especially operated at $15^{\circ}C$$ using helium as the carrier gas. The column effluents were in order of methane, (ethane, ethylene), propane, propylene, isobutane, n-butane, isobutylene, butene-1, (trans-& cis-2-butene, isopentane), (butadiene-1, 3, n-pentane). Two kinds of liquified petroleum gases in market are analysed qualitatively and quantitatively. The results indicate that use of this 2-meters TEGDE column permits the separation and identification of all the commonly encountered aliphatic gaseous hydrocarbons.

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Application of Hydrocarbons as Markers for Detecting Post-irradiation of Imported Meats and Fish (수입육류 및 어류의 방사선조사 여부 판별을 위한 Marker로 검출되는 Hydrocarbons의 활용)

  • 황금택;박준영;김충기
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.26 no.6
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    • pp.1109-1115
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    • 1997
  • Hydrocarbons were analyzed in irradiated beef, pork, dried and seasoned beef, dried anchovy, dried squid, dried shrimp, and fish paste to determine whether the hydrocarbons can be used as markers for detecting post-irradiation of the imported meat and fish products. The samples were irradiated at 0.5, 1, 3, and 6 kGy. Fat was extracted with hexane, and hydrocarbons were separated from the fat through Florisil column. The hydrocarbons were analyzed with GC. Hydrocarbons 15:0, 16:1, 17:1, 16:2, 17:2, and 16:3 in beef and pork, 17:1, 16:2, and 17:2 in dried and seasoned beef, 16:2 in dried anchovy, 16:1 and 17:1 in dried squid, 16:1, 17:1, and 16:2 in dried shrimp, and 16:1, 16:2, and 16:3 in fish paste were detected in the irradiated samples, but not in the unirradiated, so that the hydrocarbons may be used as makers for detecting post-irradiation of each item.

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Removal of diesel hydrocarbons by microwave-enhanced soil vapor extraction (Focused on Loss and Kinetic constant for Diesel Hydrocarbons)

  • 김종운;박갑성
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • pp.223-226
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    • 2004
  • In this paper, removal of diesel hydrocarbons (C$_{10}$-C$_{22}$) for dry and moist soil was investigated so that microwave-enhanced soil vapor extraction(SVE) reduced soil treatment time and raised remediation efficiency. Kinetic constants of diesel hydrocarbons with microwave energy were 7 times on dry soil and 1580 times on moist soil as much as those of SVE process without microwave energy. The diesel removals were 67.7~78.4% for $C_{10}$ and $C_{12}$, and 0~18.5% for $C_{14}$~C$_{22}$ for dry and moist soil with SVE process only. On the other hand, dry soil with microwave-enhanced SVE process showed 89.3~99.4% removal for $C_{10}$ and $C_{12}$ and 35.6~67.0% for hydrocarbons over $C_{14}$. All hydrocarbons(C$_{10}$~C$_{22}$) studied were significantly removed (93.6~99.8%) for moist soil with microwave-enhanced SVE process. Almost all diesel hydrocarbons were usually considered as semi-volatile compounds(SVOCs). Microwave-enhanced SVE process might have a great potential for remediation of soils contaminated with SVOCs.OCs.

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Excimer Fluorescence Quenching of Poly (styrene-co-acrylic acid)-Eu Complex by Simple Hydrocarbons in Tetrahydrofuran Solutions

  • Park, Doo-Hee;Kim, Kang-Jin
    • Bulletin of the Korean Chemical Society
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    • v.7 no.1
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    • pp.42-45
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    • 1986
  • Quenching of excimer fluorescence from polystyrene-acrylic acid copolymers containing $Eu^{3+}$ has been studied in tetrahydrofuran solution using simple aromatic hydrocarbons as quenchers under steady-state conditions. Aromatic hydrocarbons quenched collisionally the excimer fluorescence and their rate constants of quenching were determined. The magnitude of quenching constant is interpreted in terms of the cube root of the molar volume of quencher. Cycloalkanes were not effective in quenching the excimer fluorescence possibly due to different solubility characteristics from aromatic hydrocarbons.

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