• 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.

• Applied Chemistry for Engineering
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• v.5 no.4
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• pp.706-713
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• 1994

Isothermal vapor-Liquid equilibrium data have been measured for binary systems MTBE-methanol, MTBE-n-heptane, and methanol-n-heptane at $45^{\circ}C$ and $65^{\circ}C$ by using head space gas chromato-graphy (H.S.G.C). Among these systems a minimum azeotrope was observed in both of MTBE-methanol system and n-heptane-methanol system. Particularly n-heptane-methanol system has a heterogeneous minimum azotrope since it has an immisible region. These equilibrium data were correlated with the excess Gibbs energy model, and the thermodynamic consistency test was also carried out by using Redlich-Kister equation.

• Korean Journal of Food Science and Technology
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• v.4 no.3
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• pp.213-223
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• 1972

This paper chose the methods of methylesterification of the use of methoxide, the mixture solution of methanol-benzen-sulfuric acid in transesterification of the fat in cow's milk and modified powder milk and separated by gas liquid chromatography with F.F.A.P., D.E.G.A. as liquid phase. Quantitative analysis of the fatty acid of milk fat in cow's milk and modified powder milk was determined by gas liquid chromatography using the method of temperature programming which should be used to obtain satisfactory separation of short chain fatty acid on the chromatogram. It was found that the fatty acid composition of cow's milk and modified powder milk are all the major fatty acid of milk fat obtained by GLC analysis. Main components was found to be from butyric acid to arachidonic acid showing Fig. 3, 4, 5 and Table 4, 5, 6, 7, 8, 9.

• Elastomers and Composites
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• v.22 no.1
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• pp.11-19
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• 1987

A coil pyrolyzer and processor-controlled gas chromatograph were used for analysis of rubber for compounding ratio of the single and blend rubber vlucanizates. Variables such as sample size, pyrolysis temperature, time allowed for pyrolysis, the column packing material, its length and programmable temperature for gas chromatography were examined to obtain optimum condition for application to NR, BR and SBR blends. By application fixed conditions, three kinds of standard curves were finally obtained from thirty samples of blend vulcanizates which were prepared in the pilot plant, NIRI. It is possible to determine rubber composition and their ratio in NR, BR and SBR products by pyrolysis.

• Proceedings of the Korea Environmental Mutagen Society Conference
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• 2003.10a
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• pp.131-131
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• 2003

• Journal of Nutrition and Health
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• v.18 no.4
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• pp.293-300
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• 1985

Volatile components of Korean horseradish roots harvested at different dates were prepared by steam distillation. Samples were examined by gas chromatography (GC) and combined gas chromatography-mass spectrometry (GC-MS). The major pungent constituent, allyl isothiocyanate was confirmed add tended to increase with delayed harvest time. Pungent principles also included allyl thiocyanate, 2-phenethyl, 2-butyl, 4- pentenyl, benzyl and 3-methylthiopropyl isothiocyanates. Infrared (IR) spectroscopy study showed that allyl isothiocyanate - thiocyanate interconversion did not occur under the condition of this study.

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3877-3880
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• 2013

• 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.