• 한국대기환경학회지
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• 제18권2호
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• pp.127-137
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• 2002

Phenolic compounds in air are toxic even at their low concentrations. We had evaluated a total of five phenolic compounds (Phenol, o-Cresol, m-Cresol, 2-Nitrophenol and 4-Chloro-3-methylphenol) in artificial air using a combination of ATD/GC/MS. To compare the adsorption efficiency of these phenolic compounds, three adsorbents (Tenax TA, Carbotrap and Carbopack B) were tested. Tenax TA adsorbent was most effective of all the adsorbents used for the efficiency test. Five phenolic compounds were found to be very stable on adsorbent tubes for 4 days at room temperature. Detection limit of five phenolic compounds ranged from 0.05 to 0.08 ppb (when assumed to collect 10 L air). The calibration curve was linear over the range of 22∼ 164 ng. The reproducibility was less than 4%. Sampling of duplicate pairs (DPs) was made to demonstrate duplicate precision and sampling efficiency.

• 한국대기환경학회지
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• 제16권3호
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• pp.265-275
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• 2000

By using thermal desorption/gas chromatograph/flame ionization detector(TD/GC/FID), this study was carried out to evalute an accuracy and a precision on Benzene(B), Toluene(T), o-Xylene(X) analysis in an industrial hygiene laboratory. Limits of detection of TD/GC/FID on B, T, X were showed 13.75ng/sample or less. For the accuracy of the method by concentration levels, overall bias was showed 7.7% as an absolute value, and the pooled coefficient of variation showed 3.51%. For the precision on repeatability of peak area and retention time between within-run and between-run of analytical system, it is showed the results of within-run gave better than those of between-run. Also the accuracy by sorbents(Tenax TA and Chromosorb 106)was evaluated, and the precision on reproducibility between MDHS72 and this study was compared. It is showed it is possible for TD/GC/FID to evaluate accurately B, T, X concentration levels of less than 1ppm at indoor or outdoor of workplaces in Korea.

• Mass Spectrometry Letters
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• 제11권4호
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• pp.103-107
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• 2020

We report the application of 2,4,6-trichlorobenzoyl chloride (often referred to as Yamaguchi esterification reagent) for the selective derivatization of the carboxylic group for GC-MS with the sample preparation method optimized for GC-MS analysis. The reagent was shown to be capable of selectively turning the carboxylic group into a reaction center, i.e., anhydride, of which the further reaction was directed to a near complete formation of required esters by unique steric and electronic effects of the reagent. Using the developed method, the chiral separation of hydroxycarboxylic acids by GC-MS using non-chiral columns was successfully demonstrated.

• 한국환경과학회지
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• 제8권4호
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• pp.503-507
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• 1999

To study the residue of organophosphorus pesticides in the ocean environment on the Cheju island, EPN[O-ethyl-O-4-nitrophenyl phenylphosphonothioate] and monocrotophos [Dimethyl-1-methyl-2-methyl carba-moylvinylphosphate] of organophosphorus pesticides are surveyed on coastal environment of Cheju city and Wimi in May and October 1996. The qualified limit detection of EPN and monocrotophos are 0.005ng/mL and 0.006ng/mL in the water by GC-FPD, respectively. The qualified limit detection of EPN and monocrotophos are 0.010ng/g and 0.012ng/g in the solid such as sediment and sea organism by GC-FPD, respectively. EPN and monocrotophos are not detected in seawater and sedimnet. Moreover EPN and monocrotophos are neither detected in seaweed cava (Ecklonia cava), Agar (Gelidium amansii), turban sell(Batillus cornutus) and sea urchin(Anthocidaris Crassispina). EPN, monocrotophos used in the farm on the Cheju island are not residued in the coastal environment in the Cheju island.

• Bulletin of the Korean Chemical Society
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• 제21권11호
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• pp.1101-1105
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• 2000

A simultaneous determination method of BTEX (benzene, toluene, ethylbenzene, o,m.p-xylene) and TPH (kerosene, diesel, jet fuel and bunker C) in soil with gas chromatography/flame ionization detection (GC-FID) was described. The effects of extracti on method, extraction solvent, solvent volume and extraction time on the extraction performance were studied. A sonication method was simpler and more efficient than Soxhlet or shaking methods. Sonication with 10 mL of acetone/methylene chloride (1 : 1, v/v) for 10 min was found to be optimal extraction conditions for 20 g of soil. Peak shapes and quantification of BTEX and TPH were excellent, with linear calibration curves over a wide range of 1-500 mg/L for BTEX and 10-5000 mg/L for TPH. Good reproducibilities by sonication were obtained, with the RSD values below 10%. By using about 20 g of soil, detection limits were 0.8 mg/L for BTEX and 10 mg/L for TPH. The advantages of this procedure are the use of simple and common equipment, reduced volumes of organic solvents, rapid extraction periods of less than 20 min, and simultaneous analysis of volatile and semivolatile compounds.

• 한국식품과학회지
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• 제32권1호
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• pp.17-24
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• 2000

본 연구에서는 날로 그 생산 및 소비량이 중대 되어가는 추세에 있는 포도주의 품질향상을 이루고자 역삼투 처리기술을 이에 적용하여 시도하였는데, 포도주의 제조공정에서 필요로하는 보당과정 없이 역삼투 처리에 의해 포도 착즙액중의 순수(純水)를 제거함으로써 자체 당도를 농인 상태에서 포도주를 제조하여 일반적인 제법으로 제조한 포도주와의 비교 분석 실험을 행하였다. 또한 GC-O(Gas chromatography-Olfactometry)와CC-MS(Gas chromatography-Mass spectrometry) 그리고, 훈련된 검사자들을 통한 관능검사의 실시로 그 차이점을 구명하였는데, 관능검사 결과 RO 28 시료가 General D사(社)의 제품에 비해 전체적인 선호도면에서 월등한 것으로 나타났다. GC-O및 GC-MS를 이용한 분석결과 RO 28시료가 General 및 D사(社) 제품에 비하여 훨씬 긍정적인 향기성분의 함량이 높은 것으로 나타났으며, 비교적 긍정적인 향기성분으로 사료되어지는 ethanol, ethyl acetate 등의 chemical compound를 동정해 낼 수 있었다.

• 한국환경과학회지
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• 제14권2호
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• pp.193-199
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• 2005

To obtain the residual organochlorine pesticides in the ginseng, the methods of multi-analysis for BHC's isomer, DDT's isomer and other organochlorine pesticides by GC-ECD are surveyed. The relative retention time for $\alpha-BHC,\;\beta-BHC,\;\delta-BHC\;and\;\gamma-BHC$ is 1.000, 1.025, 1.034 and 1.056, respectively. The relative retention time for o,p-DDE, p,p-DDE, o,o-DDD, o,p-DDT, o,p-DDD, and p,p-DDT is 1.199, 1.230, 1.242, 1.286, 1.329 and 1.333, respectively. The BHC isomers, DDT's isomer and other organochlorine pesticides are separated with multianalysis condition. The qualified defection concentration for $\alpha-BHC$, Quintozene, Aldrin, Captan, $\alpha-Endosulfan$, and Dieldrin is 0.95ng/g, 0.27ng/g, 1.04ng/g, 0.63ng/g, 0.55ng/g and 0.62ng/g, respectively. The qualified defection concentration for Fenhexamid, Endrin, $\beta-Endosulfan$, o,p-DDT, Endosulfan-sulfate is 5.71ng/g, 0.61ng/g, 0.48ng/g, 0.44ng/g and 0.51ng/g, respectively. BHC, Aldrin, Dieldrin, Endrin and DDT, which were Korea Food & Drug Administration advisory pesticides, are not detected in soil environment. Also it's residual organochlorine pesticides are not polluted in the ginseng on Sangju Korea.

• 한국재료학회지
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• 제22권6호
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• pp.316-320
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• 2012

$Co_3O_4$, $Al_2O_3$ and $Co_3O_4$/$Al_2O_3$ mesoporous powders were prepared by a sol-gel method with starting matierals of aluminum isopropoxide and cobalt (II) nitrate. A P123 template is employed as an active organic additive for improving the specific surface area of the mixed oxide by forming surfactant micelles. A transition metal cobalt oxide supported on alumina with and without P123 was tested to find the most active and selective conditions as a heterogeneous catalyst in the reaction of styrene epoxidation. A bBlock copolymer-P123 template was added to the staring materials to control physical and chemical properties. The properties of $Co_3O_4$/$Al_2O_3$ powder with and without P123 were characterized using an X-ray diffractometer (XRD), a Field-Emission Scanning Electron Microscope (FE-SEM), a Bruner-Emmertt-Teller (BET) surface analyzer, and $^{27}Al$ MAS NMR spectroscopy. Powders with and without P123 were compared in catalytic tests. The catalytic activity and selectivity were monitored by GC/MS, $^1H$, and $^{13}C$-NMR spectroscopy. The performance for the reaction of epoxidation of styrene was observed to be in the following order: [$Co_3O_4$/$Al_2O_3$ with P123-1173 K > $Co_3O_4$/$Al_2O_3$ with P123-973 K > $Co_3O_4$-973 K>$Co_3O_4$/$Al_2O_3$-973 K > $Co_3O_4$/$Al_2O_3$ with P123-1473 K > $Al_2O_3$-973 K]. The existence of ${\gamma}$-alumina and the nature of the surface morphology are related to catalytic activity.

• 한국식품과학회지
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• 제39권3호
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• pp.246-254
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• 2007

본 연구에서는 녹차엽의 채취 시기와 재배지역에 따른 휘발성 향기성분의 종류, 차이, 그리고 변화를 비교하기 위하여 제주와 전남지역에서 재배한 차의 생엽을 시기별로 채취하였다. 녹차엽의 휘발성 향기 성분은 SPME를 사용하여 포집, 흡착하여 GC, GC-MS, GC-O, 그리고 retention time을 이용하여 분리된 성분을 분석, 동정하였다. 녹차엽의 휘발성분의 양은 수분함량을 고려한 건조함량을 기준으로 정량하였다. 수분함량은 생엽이 78-80%, 건조엽이 3.20-4.98% 정도였다. 휘발성 향기성분의 흡착에 사용되는 SPME 방법은 이전의 여러 방법에 비해 분석시간이 짧고 본래의 향이 아닌 방해성분의 생성이 적은 장점이 있다. 본 연구에서 사용한 SPME fiber는 7.4%의 높은 재현성을 가졌으며 표준물질(ethyl n-heptanoate)의 내부표준법에 의한 재현성 결과에서는 불안정한 peak area값(RSD 30.5-98.7%)을 가져 3.47%의 재현성 결과를 가진 외부표준법을 사용하였다. 시기에 따른 휘발성 향기 성분을 비교한 결과, 5월에 채취한 생엽의 휘발량이 가장 많았으며, Group I과 Group II 향기특성의 함량비율이 균형적이었다. 휘발량이 가장 많았던 5월에 채취한 생엽을 제주와 전남의 재배지역으로 구분하여 비교한 결과, 주 성분은 Z-3-hexenal, linalool, E-2-hexenol, n-hexanal, Z-linalool oxide, myrcene, benzyl alcohol이었다. 이러한 결과는 채엽 시기가 녹차의 향기 특성에 영향을 주며, 채엽 시기가 같더라도 지역에 따라 향기가 다른 녹차가 제조될 수 있다는 것을 나타낸다. 본 연구는 녹차를 지역에 따라 구분하는 데에도 도움이 될 것으로 예상된다.

• Mass Spectrometry Letters
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• 제3권1호
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• pp.15-17
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• 2012

Eighteen of the PDE-5 inhibitors and their analogues were analyzed using GC-EI-MS. Fourteen of them could be identified by simple GC-MS method without derivatization, but hydroxyhongdenafil, hydroxyvardenafil, xanthoanthrafil and mirodenafil could not be identified without derivatization for the high polarity due to the presence of hydroxyl groups. N,O-bis(trimethylsilyl) trifluoroacetamide (BSTFA) and N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide (MTBSTFA), widely used trimethylsilyl (TMS) derivatizing reagents, were used to improve the sensitivity of the hydroxylated analogues. And the analytes could be identified by GC-MS after the derivatization.