• Title/Summary/Keyword: GC/O

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Analysis of Alizarin Dye in Accelerated Degradation Conditions

  • Ahn, Cheunsoon
    • The International Journal of Costume Culture
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    • v.7 no.1
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    • pp.40-47
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    • 2004
  • The purpose of this research was to examine the degradation rate of alizarin in accelerated degradation conditions using the GC-MS quantitative analysis. Alizarin dye solution (2.5 x 10/sup -3/ M conc.) were kept in 150℃ oven for total of 7 days and the degradation rate was examined each day. 2.5 × 10/sup -4/M conc. alizarin dye solution was mixed with H₂O₂ according to [H₂O₂]/[dye] ratio 40 and were kept under 365㎚ UV for 2 hours, analyzed after 0, 30, 60, 90, 120min using the GC-MS. Gas chromatogram showed alizarin peak at 9.96 - 10.13 min. retention time range and residual peaks in the wide range from 9.6 to 11.1 min. Oven degradation exhibited an initial decrease in the amount of alizarin, which was followed by increasing amount in 4/sup th/ day. The decrease in the alizarin was significantly shown by the 7/sup th/ day. Same pattern was also observed in the H₂O₂/UV/O₂ degradation samples and was verified ed by the UV-VIS spectra. The differences in the amount of alizarin between 1/sup st/ day and 4/sup th/ day samples, 4/sup th/ day and 7/sup th/ day samples, and Control and 7/sup th/ day samples of the oven degradation were significant at alpha .20.

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Decomposition of volatile aromatic compounds by photochemical treatment (광화학적 방법을 이용한 휘발성 방향족 화합물의 분해)

  • Kim, Jong Hyang
    • Clean Technology
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    • v.4 no.1
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    • pp.35-44
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    • 1998
  • Photodecomposition behaviors of volatile organic compounds (VOCs ; benzene, toluene, ethylbenzene and xylenes) over UV irradiation and UV irradiation with $TiO_2$ powder catalyst were studied and the extent of degradation were also investigated under various reaction conditions. The reactions were conducted in a quartz annular reactor equipped with a medium pressure mercury lamp. As a result, the extents of degradation were 92% for toluene and ethylbenzene, 83% for benzene, and 82% for xylenes under UV irradiation. And they were 92% for toluene, 82% for xylene and ethylbenzene, and 53% for benzene under UV irradiation with $TiO_2$ powder. Analyses of reacted samples by FID-gas chromatograph with Purge & Trap concentrator and GC-MS indicated that the aromatics formed many intermediates.

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Characterization of Off-flavors from Film-Packed Soybean Sprouts (필름 포장된 콩나물의 유통 중 축적되는 이취의 종류 및 발생 특성)

  • Cho Kyoung-Shim;Kim Yong-Ho;Lee Young-Sang
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.51 no.3
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    • pp.220-226
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    • 2006
  • Soybean sprout is a traditional food and its market circulation as packed in a transparent film is increasing. To characterize the off-flavor produced from film-packed soybean sprouts, harvested soybean sprouts were stored at different temperature and oxygen conditions, and time-series changes in heads pace $O_2,\;CO_2$, ethanol (EtOH) concentrations as well as sensory off-flavor levels were measured. Lower temperature resulted in lower consumption of $O_2$, lower production of EtOH and less off-flavor. No off-flavors could be detected when atmospheric $O_2$ concentration was maintained over 4%, while alcoholic-flavor and off-flavor were initiated when $O_2$ decreased down to 2% and 1%, respectively. Under low $O_2$ conditions alcoholic-flavor following EtOH production preceeded prior to sensory off-flavor detection. Various aldehydes and fatty acids such as nonylaldehyde, decylaldehyde and stearic acid were identified by GC/MS from film-packed sprouts producing off-flavors. In conclusion to suppress off-flavor, soybean sprouts should be packed in a film which can control $O_2$ concentration over 2% and stored at low temperature around $4^{\circ}C$.

Studies on the Components of Codonopsis pilosulae Radix by GC-Mass (GC-Mass에 의한 만삼(蔓蔘) 에텔엑기스의 성분 연구)

  • Lee, Ihn-Rhan
    • Korean Journal of Pharmacognosy
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    • v.16 no.3
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    • pp.136-140
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    • 1985
  • Sixty-eight kinds of aliphatic and aromatic substances peaks from ether extract of Codonopsis pilosulae Radix were shown by GC-Mass. Of them, 3 kinds of compounds were identified as ethyl benzene, acetophenone and 1-phenyl-2-butanone, which are compared with authentic specimen, and one compound was assumed as an aliphatic $C_8H_{16}O\;or\;C_9H_{20}$.

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Adhesion Strength Measurements of Cu-based Leadframe/EMC Interface

  • Lee, Ho-Young;Jin Yu
    • Journal of the Microelectronics and Packaging Society
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    • v.6 no.2
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    • pp.1-12
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    • 1999
  • Brown oxide and/or black oxide layers were formed on the surface of Cu-based leadframe by chemical oxidation of leadframe in hot alkaline solutions, and their growth characteristics were studied. Then, to measure the adhesion strength between leadframe and epoxy molding compound (EMC), oxidized leadframe samples were molded with EMC and machined to form sandwiched double-cantilever beam (SDCB) specimens and pull-out specimens, respectively. Results showed that the adhesion strength of un-oxidized leadframe/EMC interface was inherently very poor but could be increased drastically with the nucleation of acicular CuO precipitates on the surface of leadframe. The presence of smooth faceted $Cu_2O $ on the surfaces of leadframe gave close to zero interfacial fracture toughness (Gc) and reasonable pull strength (PS). A direct correlation between Gc and PS showed that PS can be a measure of Gc only in a limited range.

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Comparison of GC-Profile on Tobacco Smoke Components (담배 연기성분의 GC-Profile 특성비교)

  • 나효환;한상빈;복진영;이운철;백순옥;장기철;양광규
    • Journal of the Korean Society of Tobacco Science
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    • v.16 no.2
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    • pp.152-162
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    • 1994
  • This study was designed to establish an analytical method for the properties of leaf tobacco smoke. Lyophilized TPM from leaf tobacco smoke was extracted with MeOH, dried under reduced pressure, and trimethyl-silylated(TMS). Gas chromatography of the material using SPB-5 column showed 120 quantifiable peaks. Among those, 26 compounds including a hydrocarbons, Neophytadiene. and Levulinic acid could be identified through GC-MS. Smoke properties of 5 manufacturing grades and 2 oriental cultivars of domestic and imported leaf tobacco including AB3O-1 were analyzed. For flue-cured tobacco, content of the compounds in the smoke was generally higher in American leaf tobacco except for glycerol compounds. For burley tobacco, domestic leaves were found to have much higher amount of smoke compound than imported leaves. Among oriental tobacco, Izmir contained slightly higher amount of smoke compounds than Basma. Key words : GC - profile. TPM. TMS. Leaf tobacco.

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Determination of the Homocysteine, Cysteine and Methionine in Human Plasma by Gas Chromatography with Electron Capture Detector (기체크로마토그래피-전자포획검출기를 이용한 혈장 중의 Homocysteine, Cysteine 및 Methionine의 동시 분석법)

  • Myung, Seung-Woon;Chang, Yoon-Jung;Yoo, Eun-Ah;Park, Joon-Ho;Min, Hye-Ki;Kim, Myung-Soo
    • Analytical Science and Technology
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    • v.12 no.5
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    • pp.408-414
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    • 1999
  • A selective and sensitive method for the derivatization of total homocysteine (Hcy) and the related compounds in plasma by gas chromatograph (GC)-electron capture detector (ECD) has been developed. To determine total homocysteine, cysteine (Cys), and methionine (Met) in human plasma using GC-ECD, analytes were reduced and converted into their N(O,S)-ethylearbonyl pentafluoropropyl (PFP) ester by derivatization with ethyl chloroformate and pentafluoropropyl alcohol (PFP-OH) in plasma. The best derivatizing agent N(O,S)-ethyl carbonyl PFP ester, was chosen by comparing the sensitivity of derivatized analysis in GC-ECD. The derivatized analytes in plasma were extracted by chloroform, and subsequently back-extracted with hexane and analyzed by GC-ECD. The calibration carves ($R^2$ > 0.990) were linear over the range $5-50{\mu}mol/L$ of Hcy and Met, $40-400{\mu}mol/L$ of Cys spiked in plasma. The detection limit observed by the established method was below $0.5{\mu}mol/L$. This method is highly sensitive and specific in the analysis of Hcy, Cys, and Met. Therefore, we suggest that this method is appropriate in the analysis of trace concentration of Hcy, Cys, and Met in biological fluids.

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Analysis of the Degradation Products of Turmeric using GC-MS (GC-MS법을 이용한 울금의 퇴화물 분석)

  • Ahn, Cheun-Soon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.31 no.6 s.165
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    • pp.859-868
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    • 2007
  • Degradation products of the dye extracted from turmeric and the turmeric dyed textiles were examined by using GC-MS after 100 oven (OV) and $H_2O_2/UV/O_2$(PER) treatments for up to 28 days. Throughout the OV degradation times, 2-propenoic acid, 3-(2-hydroxyphenyl)- was found consistently, while isovanillin, and vanillic acid were newly detected. In 28 day PER degradation sample, feruloylmethane, 2-propenoic acid, 3-(2-hydroxyphenyl)-, benzoic acid, and vanillic acid were detected as well as isovanillin. Feruloylrnethane, and 2-propenoic acid, 3-(2-hydroxyphenyl)- were detected from the degraded fabric samples. With the absence of curcuminoids in the GC-MS result, the decreasing pattern of 2-propenoic acid, 3-(2-hydrokyphenyl)- reflect the degradation of curcuminoids in turmeric extraction with the progression of OV degradation times. It is suggested that isovanillin, feruloylmethane, 2-propenoic acid,3-(2-hydroxyphenyl)-, and vanillic acid are the probable fingerprint products for determining the turmeric dye from the badly faded archaeological textiles.

Biodegradation of BTEX (benzene, toluene, ethylbenzene, xylene isomers) from organic solvent tolerant bacterium, Pseudomonas savastanoi BCNU 106

  • Kim, Jong-Su;Park, Hyeong-Cheol;Jo, Su-Dong;Kim, Gi-Uk;Bae, Yun-Wi;Mun, Ja-Yeong;Jeong, Yeong-Gi;Ju, U-Hong
    • 한국생물공학회:학술대회논문집
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    • 2003.04a
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    • pp.386-389
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    • 2003
  • Organic solvent tolerance bacteria, Pseudomonas savastanoi BCNU 106 could utilize a high contentration of benzene, toluene, ethylbenzene, xylene isomers (BTEX) as a sole carbon source. It was founded that strain BCNU 106 transformed o-xylene to 2-methylbenzyl alcohol, 2-methylbenzoic acid through direct oxygenation of methyl residue on GC-MS analysis.

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Incorporating Grapefruit Seed Extract into Gelidium corneum-Whey Protein Isolate Blend Packaging Film Increases the Shelf Life of Fish Paste

  • Lim, Geum-Ok;Hong, Yun-Hee;Song, Kyung-Bin
    • Preventive Nutrition and Food Science
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    • v.13 no.4
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    • pp.370-374
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    • 2008
  • The Gelidium corneum (GC)-whey protein isolate (WPI) blend film containing grapefruit seed extract (GSE) was prepared by incorporating different amounts (0, 0.02, 0.04, 0.08, 0.1%) of GSE into the film. The film's tensile strength (TS) and water vapor permeability (WVP) were improved by the addition of GSE. The film containing 0.1% GSE had a TS of 3.27 MPa, whereas the control had 2.64 MPa. WVP of the film was also significantly decreased by the addition of GSE. Addition of 0.1% GSE decreased the populations of Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Typhimurium by 1.0, 1.6, and 0.6 log CFU/g, respectively, compared to the control. Fish paste was packed with the GC-WPI blend film containing GSE, and microbial change in the fish paste inoculated with E. coli O157:H7, L. monocytogenes, and S. Typhimurium during storage was examined. Populations of E. coli O157:H7, L. monocytogenes, and S. Typhimurium were decreased by 0.60, 0.48, and 0.85 log CFU/g, after 7 day of storage, respectively. These results suggest packaging fish paste in the GC-WPI blend film containing GSE can extend the shelf life.