• Journal of Mechanical Science and Technology
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• 제19권12호
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• pp.2197-2204
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• 2005

The combination of Gas chromatography (GC) for separation and Flame Ionization Detection (FID) for detection and identification of the components of a mixture of compounds is a fast and strongly proved method of analytic chemistry. The objective of this research was to design a combined High-speed miniature screening Gas chromatograph along with a Flame Ionization Detector for quick, quantitative and qualitative analysis of gas components. This combined GC-FID system is suitable to detect the volatile and semi-volatile hydrocarbons present in a gas mixture. The construction made it less expensive, easy to use and movable. The complete gas path was developed. On/off valves, temperature and flow sensors and their interface electronics were used for controlling purpose. A Microcontroller was programmed to measure the temperature and gas flow using the sensors and to control and regulate them using the electronics and valves. A pocket PC with its touch screen served as a user interface for the system. Software was developed for the pocket PC, which makes the communication possible with the Microcontroller. The system parameters can be indicated in the Pocket PC as simple text and also the analysis result can be displayed.

• Applied Biological Chemistry
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• 제35권5호
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• pp.346-350
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• 1992

한국 재래식 간장의 많은 휘발성 향기성분 중에서 특징적인 향기성분을 규명하고자 하였다. 연속 수증기 증류 추출장치로 휘발성 향기성분을 추출하고 재래식 간장향을 나타내는 중성획분을 분획하여 농축하였다. 이를 GC-관능검사에 의해 각 peak성분의 방향성을 조사하고, 이 각 peak성분을 fraction collector APP-5가 부착된 preparative GC로 분획포집한 후, 이를 GC/MS로 분석 동정하였다. 그 결과 GC-관능검사에서 불쾌취를 나타내는 향기성분으로는 3-methyl-1-butanol을, 간장향을 나타내는 향기성분으로는 dimethyl trisulfide, benzeneacetaldehyde, benzeneethanol을 각각 동정하였다.

• Food Science and Biotechnology
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• 제18권1호
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• pp.18-24
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• 2009

The volatile compounds of dried sancho (Zanthoxylum schinifolium), an aromatic plant were extracted by simultaneous distillation and extraction (SDE) method and identified by gas chromatograph-mass spectrometry (GC-MS). Selected chiral constituents of sancho oil were characterized by enantiodifferentiation using multidimensional gas chromatograph (MDGC)-MS. A total of 57 compounds were identified and quantified, and the major compounds were identified estragole, nonanoic acid, octanoic acid, $\beta$-phellandrenene, and limonene. Among them, estragol (63.9%) was found as the predominantly abundant component of sancho. $\alpha$-pinene and nerolidol, and $\beta$-pinene and linalool were determined to be enantiomerically pure (100%) for their (S)-form and (R)-form, respectively. The enantiomeric composition of limonene in sancho revealed 83.9% purity for the (S)-enantiomer, whereas (E)- and (Z)-rose oxides showed mixtures of both enantiomers. The enantiomeric excess (%) for citronellal was 22.6% with the (R)-enantiomer as major enantiomer. The enantiomeric composition of these compounds can be used as parameter for authenticity control of sancho.

• Korean Chemical Engineering Research
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• 제57권4호
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• pp.507-511
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• 2019

고분자전해질 연료전지(PEMFC)의 고분자막 내구성을 평가하는데 수소투과도가 많이 사용되고 있다. 수소투과도를 쉽게 측정하는 방법으로 선형 주사 전압 측정법(Linear Sweep Voltammetry, LSV)이 주로 사용된다. 연구자마다 LSV 측정 방법에 차이가 있어 연구 결과를 비교하기가 어려울 때가 많다. 그래서 본 연구에서는 측정하기 어렵지만 정확한 값이라고 할 수 있는 기체 크로마토그래프에 의한 수소투과도와 DOE와 NEDO의 LSV 방법을 비교하여 정확성을 확인하고자 하였다. 온도와 상대습도를 변화시키며 수소투과도를 측정해 비교했을 때, DOE LSV 방법이 GC 방법과 비교해 오차 범위 5%이하의 정확성을 보였다. NEDO LSV 방법은 DOE방법과 같이 0.3V의 전류 값으로 수소투과전류밀도를 결정했을 때 오차는 감소하였다.

• KEPCO Journal on Electric Power and Energy
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• 제3권1호
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• pp.41-47
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• 2017

After $SF_6$, which is being used in power equipment as an insulating material, is classified as one of the 6 major greenhouse gases, the maintenance and the refinement of used $SF_6$ started to get attention. In regard to this, KEPCO Research Institute (KEPRI) is developing $SF_6$ recovery and refinement technology starting with establishing a comprehensive $SF_6$ analysis system. With the analysis system, qualitative and quantitative analyses of the purity and the impurities of $SF_6$ before and after recovery, and before and after refinement have been carried out. The analysis system is comprised of GC-DID (Gas Chromatograph -Discharge Ionization Detector) for trace impurities analysis, GC-TCD (Thermal Conductivity Detector) for analyses of $SF_6$ purity and major impurities concentration from several hundred ppm up to percent range, GC-MSD (Mass Selective Detector) for analyses of impurities not included in standard gas, FT-IR (Fourier Transform-Infrared) Spectrometer for analysis of HF and $SO_2$, and moisture analyzer for analysis of moisture below 100 ppm. With this analysis system, complete analysis method of $SF_6$ has been established. This analysis system is being used in the maintenance of power equipment and the development of $SF_6$ recovery and refinement technologies. In this paper, the analysis results of four samples - gas and liquid phase $SF_6$ samples from a $SF_6$ refinement system before and after refinement are presented.

• Environmental Analysis Health and Toxicology
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• 제17권2호
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• pp.117-123
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• 2002

A gas chromatographic method for the determination of airborne formaldehyde was established. In order to be highly detectable with the electron capture detector, formaldehyde was derivatized to its pentafluorobenzyl oxime form by reacting with O- (2,3,4,5,6- pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA) at pH of 4.6 and temperature of 50$^{\circ}C$ for 1 hour. Air samples were collected into a Tedlar$\^$(R)/ bag followed by transferring into water contained in two impingers in series. Collection efficiency in the front trap was higher than 90％. Measurement of selected indoor and outdoor air samples showed higher formaldehyde concentrations in indoor air environments and the importance of ventilation for reducing indoor pollution.

• 한국세라믹학회지
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• 제49권5호
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• pp.423-426
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• 2012

$Al_2O_3$/NiO powder was obtained through hydrolysis-condensation reactions and thermal treatments. An organic additive, triblock copolymer surfactant P123, was added to the starting materials to control the surface area and morphology. The synthesized powder was characterized by X-ray diffractometry (XRD), field-emission scanning electron microscopy (FE-SEM) and a Brunner-Emmett-Teller surface analysis (BET). The heterogeneous catalytic activity of this powder was applied to an epoxidation reaction of styrene and was monitored using a gas chromatograph with mass spectrophotometry (GC/MS).

• 한국토양환경학회지
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• 제3권1호
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• pp.3-9
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• 1998

본 연구는 휘발성 유기 화합물로 오염된 가솔린 지역에서 soil-gas의 분석결과로부터 오염도를 유추하는 기법에 대하여 서술 하였다. Soil-gas의 채취방법으로는 펌프를 이용한 1)grab sampling법과 흡착제 trap을 사용한 2)passive sampling법이 있다. Grab sampling법은 특정시간에 특정장소에서의 오염도를 보여주며, 반면에 passive sampling법은 특정위치에서 시간에 따른 오염도의 변화를 보여 준다. Soil-gas의 분석은 1)PID나 FID와 같은 작은 검지기에 의해서 총괄 탄화수소량을 측정할수도 있고 2)기체농도에 따라서 색깔이 변하는 지시약이 채워진 기체검지기 튜브를 사용할수도 있으며 3)여러가지 화합물을 한 번에 분석할수 있는 이동형 GC를 사용할수도 있다. Soil-gas를 이용한 측정법은 매우 값싸며 세밀한 정밀조사를 하기 위한 전단계에서 사용할 수 있는 유용한 방법으로 추천할만하다 하겠다.

• 분석과학
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• 제5권2호
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• pp.159-167
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• 1992

하천수 중 LAS의 각 동족체 및 이성체들의 성분을 BP-5 capillary column을 이용한 GC 및 GC/MS에 의하여 분리 확인 및 정량하였다. 특히 LAS 유도체의 mass chromatogram에 의해 RIC에서는 분리가 되지 않는 $5-C_{11}$과 $6-C_{11}$ 및 $2-C_{12}$, $6-C_{13}$과 $7-C_{13}$의 LAS 성분을 각각 분리 확인하였다. 중랑천, 진위천 및 한강 하루부에서 채수한 시료 중에서 탄소수 $C_{10}$, $C_{11}$, $C_{12}$ 및 $C_{13}$의 LAS 성분을 측정하였으며 동족체 및 이성체의 조성비를 구하였다. 표준품과 하천수 중 LAS 성분의 함량비를 측정 비교함으로써 하천에서 LAS의 생분해 및 동태를 추정할 수 있었다.

• 공업화학
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• 제16권4호
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• pp.513-518
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• 2005

혼합비율 및 반응온도의 변화에 따른 ZnO가 첨가된 PVC와 PS의 혼합 열분해 특성에 관한 연구를 TG와 GC-MS를 이용하여 수행하였다. 본 연구로부터 혼합물에 있어서 PS의 양이 증가할수록 액상 생성물은 증가하였으며 기상 생성물은 감소함을 알 수 있었다. 또한 ZnO의 첨가량이 증가할수록 기상 생성물과 염화수소의 발생량은 감소하였으며 염화수소의 발생 억제 및 액상 생성물의 최대수율을 얻기 위한 최적의 반응온도는 $500^{\circ}C$임을 알 수 있었다.