• Nuclear Engineering and Technology
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• v.7 no.1
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• pp.3-8
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• 1975

The quantitative analysis of various kinds of free amino acids contained in blood serum of patients with chronic mandible ostities, epidermic hemorrhagic fever, chronic renal failure and liver cirrhosis were measured with the gas-liquid chromatography (G. L. C.). The results compared with the quantity of free amino acids of healthy persons. It was found that the quantity of free amino acids were differently contained in blood serum in accordance with kinds of patients.

• Bulletin of the Korean Chemical Society
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• v.24 no.1
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• pp.99-105
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• 2003

A liquid-liquid extraction followed by evaporative concentration method was used to determine the concentration of normal, or straight chain, saturated hydrocarbons (NSH) $(C_{10}\;to\;C_{24})$ and polycyclic aromatic hydrocarbons (PAH) here defined as: fluorene, anthracene, pyrene, chrysene and perylene, in the Buriganga River water of Bangladesh. Samples were collected from 5 and 25 cm depth of water at the southern, middle and northern parts of the river at Postogolla, Sadarghat and Sowarighat stations. Hydrocarbons were extracted from 450 mL of water into 75 mL n-hexane and then concentrated into 1 or 2 mL solution by evaporation. These solutions were analyzed by gas chromatography. The highest and lowest concentrations were determined as $257\;{\mu}gL^{-1}\;for\;C_{13}\;and \;0.24\;{\mu}g\;L^{-1}\;for\;C_{22}$ at 5 ㎝ depth of water, at the northern part of the Sowarighat and southern part of the Postogolla, respectively. This method could allow the analysis of water for $C_{22}$ as low as $0.24\;{\mu}g\;L^{-1}$.

• Korean Journal of Food Science and Technology
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• v.25 no.1
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• pp.52-56
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• 1993

Flavor compounds formed in the ramyon fried in palm oil at $148-150^{\circ}C$ for 1 minute during storage at $65^{\circ}C$ were isolated and identified by gas chromatography-mass spectrometry. Their changes in the amount when the ramyon was stored at 20, 40 and $65^{\circ}C$ were also studied by using static headspace gas chromatography. Pentane, hexane, butanal, heptane, 1-pentanol, hexanal, and octane were formed during $65^{\circ}C$ storage of the ramyon and they were thought to be from linoleic and oleic acid present in ramyon. Formation of the flavor compounds was shown to increase with the storage temperature and/or storage time. Hexanal showed the highest correlation with the sensory score(r=0.87).

• Journal of Food Hygiene and Safety
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• v.8 no.1
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• pp.17-23
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• 1993

In an attempt to quantitate and qualitate residual antibiotics and antibacterial agents n meat simultaneously, we studied a gas chromatogrphy-mass spectrometry (GC/MS) analysis. For a simultaneous analysis of macrolide antibiotics such as erythromycin and tylosin in meat, the homogenization with MeOH, defatting with n-hexane, extraction with CHCl3, elution with CHCl3 : MeOH=2:1 from Sep-Pak silica cartridge, acid gydrolysis, back extraction with CHCl3, and quantitation by selected ion monitoring(SIM) mode after trimethylsilyl derivatization were performed. The recoveries of erythromycin and tylosin (CV,%) at 10 ppm fortification level were 90.59(4.89) and 45.91(0.20) , and the detection limits of those were 0.02 and 2.0 $\mu\textrm{g}$/g beef, respectively. From these results, the developed analytical method using GC/MS-SIM mode allows excellent detection and quantitation of residual macrolide antibiotics in meats, using complementary method with bio-assay.

• Journal of Power System Engineering
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• v.4 no.3
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• pp.12-18
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• 2000

Recently, our world is faced with very serious and hard problems related to the air pollution due to the exhaust emissions of the diesel engine. So, lots of researchers have studied to reduce the exhaust emissions with various methods of diesel engine that influenced the environment strong. In this paper, the quantities of the low and high hydrocarbon among the exhaust emissions in diesel engine have been investigated by the quantitative analysis of the hydrocarbon $C_1{\sim}C_6$ using the gas chromatography. This study carried out by comparing the chromatogram with diesel fuel and three kinds of mixed fuels. One is the diesel fuel blended DGM(diethylene glycol dimethyl ether) 5%. Another is the diesel fuel blended DEE(diethyl ether) 25% and DMC(dimethyl carbonate) 10%. The results of this study show that the hydrocarbon $C_1{\sim}C_6$ among the exhaust emissions of the mixed fuels are exhausted lower than those of the diesel fuel at the all load and speed.

• Korean Journal of Food Science and Technology
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• v.5 no.3
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• pp.153-156
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• 1973

Five samples of triglyceride compositions of sesame oil and decuticled sesame oil have been determined by a gas chromatographic analysis. A similar distribution pattern of triglycerides was found in these five sesame oils. It was noted that $C_{50},\;C_{52}\;and\;C_{54}$ were the major components in these samples. The results showed that contents of $C_{50},\;C_{52}\;and\;C_{54}$ triglyceride types in five sesame oils were within $3.0{\sim}4.5%,\;23{\sim}28%\;and\;68{\sim}74%,$ respectively.

• YAKHAK HOEJI
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• v.30 no.1
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• pp.47-50
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• 1986

The enantiomers of five amino acids (alanine, valine, threonine, leucine and phenylalanine) could be separated by gas chromatography with optically active (S)-5-isopropyll-$N^3$-phenyl-2-thiohydantoinic stationary phase, which prepared from L-valine and phenylisothiocyanate. Gas chromatographic separations on methylesterificated and N-trifluoroacetylated amino acids have been conducted in isothermal at several column temperatures (180~190, 200, $210^{\circ}C$). The separation factors were 1.29 (alanine, $190^{\circ}C$), 1.35 (valine, $190^{\circ}C$), 1.33 (threonine, $190^{\circ}C$), 1.17 (leucine, $190^{\circ}C$) and 1.05 (phenylalanine, $190^{\circ}C$) and D-isomers eluted prior to L-isomers in every instance. The result of this experiment shows that this stationary phase can be used for the separation of the other amino acids enantiomers.

• Korean Journal of Food Science and Technology
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• v.8 no.2
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• pp.85-89
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• 1976

The separation and determination of dicarbonyls such as diacetyl, methylglyoxal and triose reductone in their mixed aqueous solution were carried out by means of gas chromatography with transformation of these compounds into quinoxaline derivatives with o-phenylenediamine. A column used for this experiment was consisted of Celite 545 (80-100 mesh) coated with 5% Silicon Gum SE-30. The column temperature was $180^{\circ}C$. It is desirable that this approach will be applicable to dicabonyl study in gas chromatographic determination.

• Analytical Science and Technology
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• v.13 no.5
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• pp.592-600
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• 2000

The concentration of free fatty acids and fatty acid composition as well as cholesterol supersaturation in bile may be an important factor in the gallstone formation. Therefore, we simultaneously determinded 23 fatty acids in bile by selected ion monitoring (SIM) method of gas chromatography-mass spectrometry (GC-MS). Biliary fatty acids were extracted by aminopropyl column and the extracts with (phospholipid fraction) or without (free fatty acid fraction) alkaline hydrolysis of phospholipid were derivatized with MSTFA/TMCS (N-methyl-N-trimethylsilyl-trifluoroacetamide/trimethylsilylchloride) mixture in order to be detected on the GC-MS. The recovery range of this method was 61.1-99.0% and the RSD value of within-a-day and day-to-day test were 3.1-25.6% and 3.8-27.0%, respectively. Using this method, biliary profile was investigated in the bile of normal controls and patients with gallstones. The amounts and their distribution of free and phospholipid fatty acids showed different pattern between normal subjects and patients.

• Preventive Nutrition and Food Science
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• v.16 no.1
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• pp.45-54
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• 2011

Volatile components in commercial pine needle (Pinus densiflora S. and Z.) powder were extracted using simultaneous steam distillation and a solvent extraction (SDE) apparatus, and were analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 230 compounds divided into 13 groups were identified, which included alcohols (42), ketones (39), aldehydes (32), terpenes (30), alkenes (17), esters (14), furans (14), benzenes (10), alkanes (8), napthalenes (7), acids (6), miscellaneous compounds (6), and phenols (5). Among the 230 compounds identified, 96 compounds were positively confirmed and quantified, and the rest of the compounds were tentatively identified. The major volatile components identified at relatively high levels were dodecanoic acid, hexadecanoic acid, hexanal, benzaldehyde, (Z)-3-hexen-1-ol, 1-penten-3-one, limonene, and $\beta$-caryophyllene oxide. Among the groups, terpenes accounted for 60.18% of the total concentration of all the volatile components. Some volatile components might account for the unique aroma and the biological activity of the sample.