• Journal of the Korea Society of Computer and Information
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• v.21 no.5
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• pp.167-175
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• 2016

The volatile component analysis of 82 commercialized liquors(44 samples of single malt whisky, 20 samples of blended whisky and 18 samples of brandy) was carried out by gas chromatography after liquid-liquid extraction with dichloromethane. Pattern recognition techniques such as principle component analysis(PCA), cluster analysis(CA), linear discriminant analysis(LDA) and partial least square discriminant analysis(PLSDA) were applied for the discrimination of different liquor categories. Classification rules were validated by considering sensitivity and specificity of each class. Both techniques, LDA and PLSDA, gave 100% sensitivity and specificity for all of the categories. These results suggested that the common characteristics and identities as typification of whiskies and brandys was founded by using multivariate data analysis method.

• Journal of Korean Society of Forest Science
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• v.81 no.2
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• pp.177-182
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• 1992

Soil air $CO_2$ concentrations were measured in two soil depths (O and B horizon) by (1) the use of the Draeger direct reading chromatographic tubes and (2) syringe gas collections with gas chromatographic detection in a Spodosol supporting low elevation, commercial spruce-fir forest, Maine, USA, Mean soil air $CO_2$ concentrations(%) during the growing season of 1991 ranged from 0.11 in the O horizon by the Draeger method to 0.29 in the B horizon by the gas chromatographic method. Soil air $CO_2$ concentrations by the Draeger method were lower than those obtained using the gas chromatographic method for both soil horizons. However, data from the two methods were significantly(p<0.01) correlated and paralleled each other relative to temporal patterns. Positive and highly significant correlations existed between soil air $CO_2$ concentrations and soil temperature, although correlation coefficients only ranged from 0.13 to 0.32, depending on the method and horizon chosen.

• Applied Biological Chemistry
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• v.35 no.1
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• pp.36-41
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• 1992

Several commercial cottonseed, corn and rapeseed oils were stored at $60^{\circ}C\;and\;70^{\circ}C$ with daily exposure of fluorescent light for 12 hours and evaluated their rancidity by headspace gas chromatographic analysis of pentanal and hexanal. The data of gas chromatographic analysis was compared with organoleptic flavor evaluation. For headspace gas chromatographic analysis, the volatile compounds were recovered by porous polymer trap and flushed into a fused silica capillary column at $250^{\circ}C$. Twenty-three GC peaks were identified on the basis of relative retention time of reference compounds and gas chromatography-mass spectrometry. The results showed that the contents of pentanal and hexanal were linearly increased during storage. A very simple linear relationship was found between organoleptic flavor scores and amounts of two volatile compounds with very high correlation coefficient. This results suggested the possible implication of pentanal and hexanal as an quality index for rancidity evaluation of cottonseed, corn and rapeseed oils.

• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1247-1251
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• 1998

A method is developed for simultaneously determining ethanol and acetic acid in vinegars by quantitative packed-column gas chromatography. Vinegars were filtrated and directly chromatographed on a $2\;m{\times}2\;mm$ stainless steel column packed with Tenax-GC, 80/100. Ethanol, isopropy alcohol as an internal standard, and acetic acid were completely separated within 20 min of running time without any interfering peaks. The accuracy of packed column gas solid chromatography (PCGSC) was discussed compared to the analytical data by titration, high performance liquid chromatography and capillary column gas liquid chromatography (CCGLC).

• Archives of Pharmacal Research
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• v.12 no.1
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• pp.58-61
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• 1989

Studies of selectivity of hydrogen bond formation in chiral solute-solvent systems have been performed by $^1H\;and\;^{13}C$ nuclear magnetic resonance techniques. These data are correlated with the results of gas chromatographic investigations of the same systems. Interactions between the optically active solvent(N-(N-benzoyl-L-amino acid)-anilide) and optically active solute (N-trifluoroacetyl -L-alanyl isopropyl ester) were examined. NMR evidence indicated that hydrogen bonding interaction occurred between two N-H portion and on peptidyl carbonyl portion in stationary phase and solute molecule on three points. The association constants of solvent-solute interaction were calculated and the structure of the diastereomeric association complex between N-(N-benzoyl-L-valyl)-anilide and N-TFA-L-alanyl isopropyl ester was proposed.

• Journal of Microbiology and Biotechnology
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• v.10 no.4
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• pp.476-481
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• 2000

A linear correlation, by the stepwise multiple regression analysis, was found between the sensory test of Sigumjang aroma and the gas chromatographic data which were transformed with logarithm. GC data is the most objective method to evaluate Sigumjang aroma. A multiple correlation coefficient and a determination coefficient of more than 0.9 were obtained at the 9th and 13th steps, respectively. At step 31, the coefficient of determination level of 0.95 was attained. The accuracy of its estimation became higher as the number of the variables entered into the regression model increased. Over 90% of the Sigumjang aroma was explained by 13 compounds indentified on GC. The contributing proportion of the peak 26 was the highest followed by peaks 57 (9.27%), 29 (7.51%), 54 (6.01%), 8 (5.99%), 49 (4.97%), and 13 (4.11%).

• Applied Biological Chemistry
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• v.34 no.2
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• pp.149-153
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• 1991

Several commercial soybean oils were stored at $20^{\circ}C,\;40^{\circ}C$ and $60^{\circ}C$ with daily exposure of fluorescent light for 12 hours and evaluated their rancidity by headspace gas chromatographic analysis of pentanal and hexanal. The data of gas chromatographic analysis was compared with organoleptic flavor evaluation. For headspace gas chromatographic analysis, the volatile compounds were recovered by porous polymer trap and flushed into a fused silica capillary column at $250^{\circ}C$, The pentanal and hexanal separated were identified by gas chromatography and gas chromatography-mass spectrometric method. The results showed that the contents of pentanal and hexanal were linearly increased during storage for 100 days. A very simple linear relationship was found between organoleptic flavor scores and amounts of two volatile compounds with very high correlation coefficient. A similar linear relationship was also obtained for acid and peroxide value with sensory data. This results suggested the possible implication of pentanal and hexanal as an quality index for rancidity evaluation of soybean oil.

• Archives of Pharmacal Research
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• v.9 no.3
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• pp.131-138
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• 1986

A specific and sensitive gas chromatographic (GC) procedure with the flame photometric detector (FPD) was developed for determination of barbiturates such as barbital, allobarbital, secobarbital, phenobarbital and thiopental in plasma. In order to evaluate the performance of the FPD, the results were campared with those of the flame ionization detector (FID). After extraction of barbiturates from plasma, the barbiturates were quantitatively N, N-dimethylthiometyl (MTM)-derivatized with methylthiomethyl chloride in 1, 8-diazabicyclo [5, 4, 0] undec-7-ene catalyst. The data indicate that the FPD is about 4 times more sensitive than the FID for barbiturates, although it is less reproducible. The FPD also produced chromatogram with less back ground for extracted plasma sample. The FPD also produced chromatogram with less background for extracted plasma sample. The minimum detectable amount of MTM-thiopental on 3% OV-225 column was 4, 4fmol and that of other MTM-barbiturate was about 10.0fmol.

• The Korean Journal of Food & Health Convergence
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• v.9 no.4
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• pp.11-18
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• 2023

Oil was extracted from cashew nuts. The physicochemical parameters of the oil were determined. A chromatographic assay of the oil was carried out using Gas Chromatography-Mass Spectrometry. Seventeen compounds were detected: Phenol, Phenol 2-methyl-, Cyclohexene 4, 4-dimethyl-, m-Fluoro-2-diazoacetophenone 4-dimethyl-, Tetradecanoic acid, Phenol 4-octyl-, n-Hexadecanoic acid. Others are 9, 12-Octadecadienoic acid (Z, Z) - methyl ester, Hexadecanoic acid methyl ester, Methyl stearate, Dodecanoic acid methyl ester, 9, 12, 15-Octadecatrienoic acid methyl ester, 9, 12, 15-Octadecatrienoic acid (Z, Z, Z)-, Oleic acid, Octadecanoic acid, Tetracosanoic acid and 9-Octadecenoic acid methyl ester. Among the components are omega three and omega six essential free fatty acids. The rheological profiling and flow properties of cashew nut oil were determined using a Programmable Rheometer. Cashew nut oil exhibits slight dilatant behaviour at the low end of shear rate. The long chain and high molecular weight of its constituents controlled its rheology. Long-chained 9-Octadecenoic acid methyl ester, 9, 12-Octadecadienoic acid (Z, Z) - methyl ester, Tetracosanoic acid and methyl stearate, coupled with their high molecular weights are responsible for the shear thickening effect observed. Two models, Carreau-Yasuda and Ostwald-de Waele Power Law were employed to fit the rheological data. The Carreau-Yasuda model followed well the data.

• Korean Journal of Food Science and Technology
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• v.16 no.2
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• pp.242-250
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• 1984

Flavor components extracted from eighty species of Korean ordinary soy sauce were analyzed by gas chromatography. The relationship between the sensory scores of soy sauce flavor and the gas chromatographic data transformed with variables were analysed by method of multiple regression analysis. Simple correlation between values of each peak and sensory scores were totally low. The tenth and 12th peak had the highest correlation, 0.331. Determination coefficients of data obtained by transformation of each variables were not significantly different from each other. Flavor of soy sauce was explained about 56% at step 16 in case of stepwise multiple regression analysis of absolute values. The fact that the minimum standard errors of an estimate was found at the 16th step suggests the importance of selecting of independent variables from the whole gas chromatogram together with the results of F ratio. In the contributing proportion of each peak examined, peak 10 and 12 were contributing mainly to the good flavor of soy sauce.