• Journal of Environmental Science International
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• v.23 no.7
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• pp.1253-1268
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• 2014

This study was investigated twenty two hazardous chemicals compounds for effluents of nine sewage treatment plants (STPs) and one waste water treatment plant (WWTP) in the Nakdong Ri-ver Basin. They are eleven phthalates(DMP, DEP, DIBP, DBP, BEEP, DNPP, DHP, DCP, DEHP, DNOP, Dinonyl phthalate, seven aliphatic hydrocarbons(n-Tridecane, n-Tetradecane, n-Pentadecan-e, n-Hexadecane, n-Heptadecane, n-Octadecane, n-Nonadecane, Isoquinoline, 2-Chloropyridine, 2-N-itrophenol, and Benzophenone. The twenty two compounds were analyzed by gas chromatograp-hy mass spectrometry (GC/MS) with liquid-liquid extraction (LLE). Twenteen of twenty two subs-tances were detected. They were DMP, DEP, DIBP, DBP, DEHP, n-Tetradecane, n-Pentadecane, n-Heptadecane, n-Octadecane, n-Nonadecane, Isoquinoline and Benzophenone. Among these, DEHP, DEP and Benzophenone were most frequently observed. They were obtained as $ND{\sim}36.881{\mu}g/L$, $ND{\sim}0.950{\mu}g/L$, $ND{\sim}2.019{\mu}g/L$, respectively. When the substances were calculated the average concentration at 10 points, the maximum average detection concentration was investigated at the Dalseocheon STP.

• Particle and aerosol research
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• v.14 no.4
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• pp.153-169
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• 2018

To identify a variety of organic compounds in the ambient aerosols, the two-dimensional gas chromatography-time of flight mass spectrometry (GCxGC) system (2DGC) has been applied. While 2DGC provides more peaks, the amount of the generated data becomes huge. A two-step approach has been proposed to efficiently interpret the organic aerosol analysis data. The two-dimensional 2DGC data were divided into 6 chemical groups depending on their volatility and polarity. Using these classification standards, all the peaks were subject to both qualitative and quantitative analyses and then classified into 8 classes. The aerosol samples collected in Seoul in summer 2013 and winter 2014 were used as the test case. It was found that some chemical classes such as furanone showed seasonal variation in the high polarity-volatile organic compounds (HP-VOC) group. Also, for some chemical classes, qualitative and quantitative analyses showed different trends. Limitations of the proposed method are discussed.

• Korean Journal of Food Science and Technology
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• v.45 no.3
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• pp.382-384
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• 2013

We evaluated the presence of uniconazole residual pesticide in agricultural products by using multiclass pesticide multiresidue methods. Samples were collected from January to August, 2012. The pesticide was detected in 14 samples among the 3,632 samples tested. Amount of the uniconazole pesticide ranged from 0.098 to 2.2 mg/kg in the 14 samples. This method was described for the simultaneous determination of uniconazole by using gas chromatography with an electron capture detector (GC-ECD) and mass spectrometry (MS). For evaluating the GC-ECD method, uniconazole was spiked into gyeojachae at a level of 0.05, 0.5 mg/kg. The recoveries of uniconazole with the GC-ECD method ranged from 98.9-109.4%. The results indicate that our method of simultaneous analysis is applicable to uniconazole analysis.

• Korean Journal of Food Science and Technology
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• v.27 no.5
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• pp.736-741
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• 1995

This study was conducted to investigated the change of volatile flavor components of Cassia tora seeds during roasting treatments. The flavor components of Cassia tora seeds were analyzed by gas chromatography(GC) and combined gas chromatography-mass spectrometry(GC/MS). Among the flavor compounds collected by simultaneous steam distillation and extraction(SDE) method, 38 components were separated and identified. They consisted of 3 pyrazines, 4 pyrroles or pyridine, 4 alcohols, 11 aldehydes or ketones, 9 furans or phenols and 7 others. The flavor compounds collected from unroasted Cassia tora seeds were 7 components. During roasting process, many other flavor components were formed and increased in their contents. The contents of pyrazines and furans were highest and increased conspicuously, whereas, the contents of aldehydes, ketones, alcohols and pyridines were not increased significantly.

• Korean Journal of Food Science and Technology
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• v.27 no.3
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• pp.380-386
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• 1995

An attempt was made to determine the effects of drying methods including shady air drying, presteamed and shady air drying, microwave drying, and freeze drying on the volatile flavor components with Commelina communis L.. Essential oils from the samples were isolated by simultaneous steam distillation-extraction(SDE) method using diethyl ether as solvent. Concentrated samples were analyzed by gas chromatography(GC) and combined gas chromatography-mass spectrometry(GC-MS). Respective 29, 47, 36, and 24 volatile flavor components were identified in shady air dried samples, presteamed and shady air dried samples, microwave dried samples, and freeze dried samples. The kinds and amounts of volatile flavor components were evidently depended upon the drying methods. 6,10,14-trimethylpentadecanone was regarded as the most abundant component in shady air dried samples, 6,10,14-trimethyl-2-pentadecanone in presteamed and shady air dried samples, neophytadiene in microwave dried samples, and ethyl acetate in freeze dried samples.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.6
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• pp.702-708
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• 2018

Volatile organic compounds (VOCs), as a significant air pollutant, is generated mainly from the burning of fossil fuels, building materials using painting, etc. The inhalation of a certain amount of VOCs can be deleterious to human health, e.g., headaches, nausea and vomiting. In addition, it can also cause memory loss and even increase the rate of leukemia. Therefore, as one of the methods for reducing VOCs in air, polyacrylonitrile/fly ash (PAN/FA) composite nanofibrous membranes were fabricated by electrospinning. To observe their VOCs adsorption capacity, the morphological structure of PAN/FA nanofibrous mats was investigated by field emission scanning electron microscopy (FE-SEM), and the VOCs (chloroform, benzene, toluene, and xylene) adsorption capacity of PAN/FA membranes were tested by gas chromatography/mass spectrometry (GC/MS). The results indicated that the PAN nanofiber containing 40 wt. % FA powder had the smallest fiber diameter of 283 nm; they also showed the highest VOCs adsorption capacity compared to other composite membranes.

• Journal of the Korean Chemical Society
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• v.42 no.3
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• pp.266-276
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• 1998

Cholesterol supersaturation in bile, which causes gallstone formation, is the result of low bile acid secretion or high cholesterol secretion. The quantitative analysis of cholesterol, bile acids and sterols which are precursors of cholesterol have been used to examine the changes in bile component. We described a simple, sensitive and reproducible method for simultaneous determination of cholesterol, five bile acids and seven sterols in human bile juices and gallstones by capillary column gas chromatography-mass spectrometry (GC/MS). Clinical samples were hydrolyzed by alcoholic KOH, extracted twice (pH 14 and 1) and derivatized to trimethylsilyl (TMS) ether with $MSTFA/NH_4I$ (N-methyl-N-trimethylsilyltrifluoroacetamide/ammonium iodide) mixture in order to be detected on the GC/MS. The good quality control data were obtained through within-a-day and day-to-day test (RSD values were 1.72-13.79, 0.68-14.10, respectively) and the recovery range of them was 73.56-96. 95 Using this method, biliary and gallstone compositions in the patients with intrahepatic stones were analyzed. The amounts and its relative distribution of cholesterol, bile acids and sterols showed different pattern in bile juices and gallstones.

• Analytical Science and Technology
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• v.29 no.1
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• pp.49-55
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• 2016

A ketone body (acetoacetic acid, β-hydroxybutyric acid, and acetone) increases from blood or urine when bio-energy dependence pays more fatty acid than glucose. However, in case oxidation of fat is greater than the capacity of the citric acid cycle the fatty acid oxidation is made from acetoacetyl CoA to acetoacetate then, again form β-hydroxyburytic acid to acetone, the diffusion take place into the blood. Enzymes that oxidize ketone body in the brain and nerve tissue blood ketone dody is increased during prolonged fasting, brain used it as energy. In this study, we developed the rapid two step derivatization method for sensitive detection of the ketone body by GC-MS/SIM. The plasma was deproteinized and then the hydroxy and carboxyl groups of ketone body are subjected to extraction and drying then, keto-group were derivatized with hydoxylamine at 60℃ for 30 min for oximation. Then it was trimetyl-silylated with BSTFA at 80℃ for 30 min and analyzed using a GC-MS. The linear ranges were in between 0.001 μg/mL and 250 μg/mL for β-hydroxy butyrate, and acetoacetate. The method detection limits were below 0.1 pg over each target compound determined. The mean recoveries (%) of target compounds were ranged from 88.2 % to 92.3 % at 1 µg/mL, from 89.5 % to 94.8 % at 10 μg/mL, with RSD of 6.3-9.4 %. This method could be applied to quantification of ketone bodies which are seen in the keto-acidosis in children and adults from a variety of diseases that cause ketones in the blood and urine.

• Analytical Science and Technology
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• v.25 no.4
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• pp.236-241
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• 2012

There are many industrial factories in the central Nakdong river basin and have been occurred water pollution accidents by hazardous chemicals such as phenol, 1,4-dioxane and perchlorate. In this study, ten compounds of semi-volatile organic compounds (SVOCs) (dichlorvos, toluene-2,4-diisocyanate, 4,4'-methylenedianiline, 4,4'-methylenebis (2-chloroaniline), diethyl phthalate, di-n-butyl phthalate, butyl benzyl phthaltate, bis (2-ethylhexyl) adipate, benzophenone, 4,4'-bisphenol A) of hazardous chemicals which may be potentially discharged into the Nakdong river, were determined by gas chromatography-mass spectrometry (GC-MS) with disk-type solid-phase extraction. Accuracy and precision were in the range of 75.6~110.5%, and 4.6~12.7%, respectively and recovery was in the range of 72.4~127.9%. Three compounds (bis (2-ethylhexyl)adipate, benzophenone, 4,4'-bisphenol A) were detected in industrial wastewater such as wastewater treatment plants (WWTPs) and wastewater discharge facilities in the Nakdong River basin.

• Korean Journal of Food Science and Technology
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• v.21 no.3
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• pp.391-398
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• 1989

Triglyceride molecular species In some vegetable oils were analyzed by capillary column gas chromatography and electron impact ionization mass spectrometry utilizing selected ion monitoring. Triglycerides were separated according to their molecular weights and their degrees of unsaturation on $25m{\times}0.25mm$ fused silica open tubular capillary column coated with a phenylmethylsilicone gum stationary phase and in an analysis time less than 13 min. Triglyceride molecular species were identified by analyzing the fragment ions having the same time on the selected ion monitoring profile . The major triglyceride molecular species in each oils were $C_{18:1}.\;C_{18:2}.\;C_{18:2}(OLL:18.3%),\;C_{18:2}.\;C_{18:2}.\;C_{18:2}(LLL;\;14.3%),\;C_{18:0}.\;C_{18:2}.\;C_{18:2}(SLL;\;14.1%),\;C_{16:0}.\;C_{18:2}.\;C_{18:2}(PLL;\;13.2%),\;C_{16:0}.\;C_{18:2}.\;C_{18:1}(PLO;\;11.6%)$ in corn oil, $C_{18:2}.\;C_{18:2}.\;C_{18:2}(LLL;\;18.0%),\;C_{18:1}.\;C_{18:2}.\;C_{18:2}(OLL;\;18.0%),\;C_{16:0}.\;C_{18:2}.\;C_{18:2}(PLL;\;17.1%)$ in safflower oil, $C_{16:0}.\;C_{18:2}.\;C_{18:2}(PLL;\;23.5%),\;C_{16:0}.\;C_{18:2}.\;C_{18:1}(PLO;\;13.8%),\;C_{18:0}.\;C_{18:1}.\;C_{18:1}(SOO;\;13.5%),\;C_{18:1}.\;C_{18:2}.\;C_{18:2}(OLL;\;10.6%)$ in cottonseed oil.