• Journal of the Korean Chemical Society
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• v.35 no.4
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• pp.350-354
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• 1991

Characteristics of a gas chromatographic detector using glow discharge as the ionization source was studied in helium flow. Discharge current greater than 10$_6$ A was observed from the electric field 400 V/mm for the electrode distance 1 mm. The discharge current of 0.1~0.3 mA could be used for the detection of organic compounds. Discharge current was almost constant for the helium flow rate greater than 10 ml/min, but the discharge was easily disappeared by an injection of a small amount of organic compound in the flow rate of 0~30 ml/min. From the decrement of the discharge current depend on several compounds, it was suggested that the sensitivity of the glow discharge ionization chromatographic detector is strongly influenced by the molecular weight of the compounds.

• Journal of Korean Society for Atmospheric Environment
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• v.4 no.2
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• pp.11-19
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• 1988

대기오염물질 속에 함유되어 있는 다환방향족 탄화수소 (PAHs)는 분자식 구조가 비슷한 수십개의 이성질체가 여러 종류의 유기화합물과 혼합되어 존재한다. 본 연구에서는 환경오염 시료중의 PAHs를 분석하는데 있어서 분석방법과 결과를 비교하기 위하여 지침이 될 수 있는 환경표준 기준물을 개발할 목적으로 굴뚝 안쪽벽에서 긁어 채취한 검댕을 시료로 선책하여 액체/액체 용매 추출방법에 의해 PAHs 분류부분을 얻었다. Phenanthrene 이외의 30여종의 PAHs 화합물을 가스크로마토그라피의 머무른시간과 가스크로마토그라피/질량분석기에 의하여 분리, 판명하였고 5종의 주 PAHs 화합물을 정확하게 정량 분석하였다. 정량분석 결과의 신뢰도, 정확도, 정밀도는 미국 NBS의 표준기준물 1647을 분석하여 검정치와 비교함으로써 평가하였다.

• Journal of Industrial Technology
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• v.19
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• pp.409-413
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• 1999

Chemical oxidation of humic acid by ozonation process was investigated in the batch reactor. Aldehydes and ketone were identified as PFBOA derivatives in ozonated humic acid solutions using gas chromatography with PDECD. The formaldehyde was as a main by-product of ozonation. The characteristics of the formaldehyde production were discussed with respect to concentration at different experimental conditions.

• Journal of the Korean Chemical Society
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• v.51 no.1
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• pp.51-55
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• 2007

The fatty acid composition of thiocyanate utilizing Bacillus brevis isolated from carbonization wastewater was determined by Gas Chromatography and the results were analyzed. In addition to the saturated and unsaturated straight chain fatty acids this B. brevis strain contained a hydroxy fatty acid. The hydroxy fatty acids in general are shown to be interesting chemotaxonomic markers of bacteria. Cyclopropane fatty acids are totally absent in this strain. A comparison of the fatty acid composition of this strain with B-33 and B-34 strains of Bacillus brevis shows that there are deviations among these strains. The deviation in Bacillus brevis could be due to the stress effect of thiocyanate. This result supports that fatty acid synthesis depends highly on the environment.

• Journal of the Korean Chemical Society
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• v.28 no.5
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• pp.323-327
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• 1984

Nicotine was reacted with an equimolar amount of ozone in methylene chloride and distilled water. The reaction mixture was separated by column chromatography or thin layer chromatography and then purified by vacuum distillation. The six compounds obtained from this reaction were characterized by NMR, IR and Mass spectrometry. These were identified as unchanged nicotine, nornicotine, anabasine, ${\beta}$-nicotyrine, cotinine and nicotine-N-oxide. From these results, reaction mechanism for the ozonolysis ofon nicotine was proposed; the pyrrolidine ring is attacked by ozone at the 1'-position followed by further transformation.

• Applied Biological Chemistry
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• v.35 no.2
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• pp.132-138
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• 1992

For effective determination of methylthiohydantoin amino acids(MTHs) by gas liquid chromatography in the protein sequencing, derivatization with N-methyl-N-(tert.-butyl-dimethylsilyl)trifluoroacetamide(MTBSTFA), a new silylating reagents, was attempted instead of trimethylsilyl(TMSi) derivatives by N,O-bis(trimethylsilyl)trifluoroacetamide(BSTFA) used up to the present and N(O)-butyldimethylsilyl MTHs derivatized by MTBSTFA were analysed on HP-1 capillary column. Twenty one protein amino acids except cystine were indentified. Especially arginine that did not detected with TMSi derivative on packed column until now was resolved by derivatization with MTBSTFA. N(O)-butyldimethylsilyl MTHs showed multiple peaks by MTBSTFA were proline, isoleucine, glycine and tyrosine and hydroxyproline especially showed several extraneous peaks more than two. Calibration curves of N(O)-butyldimethysilyl MTHs of amino acids in the range of $2.5\;nmol{\sim}7.5\;nmole$ showed good linearity. however, those of lysine, histidine and arginine showed linearity in the range of $5.0\;nmole{\sim}15.0\;nmole$. Correlation coefficients and regression coefficients of all calibration curves were highly significant(p<0.001).

• Journal of the Korean Chemical Society
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• v.9 no.2
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• pp.106-109
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• 1965

The effects of methyl borate, iodine and potassium iodide on the Co-60 gamma radiolysis of methanol have been reinvestigated at room temperature, utilizing an experimental technique based on gas chromatographic determinations of the gaseous products of the radiolysis. The presence of methyl borate reduces the yield for ethylene glycol to some extent, with slight reductions of the yields for hydrogen and formaldehyde. The presence of iodine causes appreciable reduction of the yields for hydrogen, formaldehyde and ethylene glycol, with a slight reduction of the yield for methane. The presence of potassium iodide reduces the yields for hydrogen and ethylene glycol but increases that for formaldehyde. A mechanism of the radiolysis reaction is discussed, on the basis of the observed data.

• Journal of the Korean Society for Railway
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• v.12 no.6
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• pp.1059-1066
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• 2009

Recently, the amount of thermosetting plastic wastes has increased with the production of reinforced plastic composites and causes serious environmental problems. The epoxy resins, one of the versatile thermosetting plastics with excellent properties, cannot be melted down and remolded as what is done in the thermoplastic industry. In this research, a series of experiments that decompose epoxy resin and recover carbon fibers from carbon fiber reinforced epoxy composites applied to railway vehicles was performed. We experimentally examined various decomposition processes and compared their decomposition efficiencies and mechanical property of recovered carbon fibers. For the prevention of tangle of recovered carbon fibers, each composites specimen was fixed with a Teflon supporter and no mechanical mixing was applied. Decomposition products were analyzed by scanning electron microscope (SEM), gas chromatography mass spectrometer (GC-MS), and universal testing machine (UTM). Carbon fibers could be completely recovered from decomposition process using nitric acid aqueous solution, liquid-phase thermal cracking and pyrolysis. The tensile strength losses of the recovered carbon fibers were less than 4%.

• Journal of Plant Biotechnology
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• v.42 no.1
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• pp.60-70
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• 2015

The aim of this study was to investigate whether fourier transform infrared (FT-IR) spectroscopy can be applied to simultaneous determination of fatty acids contents in different soybean cultivars. Total 153 lines of soybean (Glycine max Merrill) were examined by FT-IR spectroscopy. Quantification of fatty acids from the soybean lines was confirmed by quantitative gas chromatography (GC) analysis. The quantitative spectral variation among different soybean lines was observed in the amide bond region ($1,700{\sim}1,500cm^{-1}$), phosphodiester groups ($1,500{\sim}1,300cm^{-1}$) and sugar region ($1,200{\sim}1,000cm^{-1}$) of FT-IR spectra. The quantitative prediction modeling of 5 individual fatty acids contents (palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid) from soybean lines were established using partial least square regression algorithm from FT-IR spectra. In cross validation, there were high correlations ($R^2{\geq}0.97$) between predicted content of 5 individual fatty acids by PLS regression modeling from FT-IR spectra and measured content by GC. In external validation, palmitic acid ($R^2=0.8002$), oleic acid ($R^2=0.8909$) and linoleic acid ($R^2=0.815$) were predicted with good accuracy, while prediction for stearic acid ($R^2=0.4598$), linolenic acid ($R^2=0.6868$) had relatively lower accuracy. These results clearly show that FT-IR spectra combined with multivariate analysis can be used to accurately predict fatty acids contents in soybean lines. Therefore, we suggest that the PLS prediction system for fatty acid contents using FT-IR analysis could be applied as a rapid and high throughput screening tool for the breeding for modified Fatty acid composition in soybean and contribute to accelerating the conventional breeding.