• Korean Journal of Food Science and Technology
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• v.30 no.2
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• pp.260-265
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• 1998

In this study, volatile flavor compounds in sesame oils were analyzed by using pure-and-trap method and a gas chromatography. 2-ethoxy-3-ethylpyrazine was used as an internal standard and retention index (Kovat's number) for the volatiles were determined through the use of a n-paraffin $(C_5-C_{25})$ standards. A total of 33 volatile compounds including 14 pyrazines, 7 thiazoles, 4 pyridines, 2 oxazoles and 6 others were identified in the sesame oils. By comparing the total yields of volatile flavor compounds, the pyrazines are the most abundant compounds all of the oil samples and considered as good contributor to characteristic flavor of sesame oil. The oil from the seeds roasted in the electric pan at $200^{\circ}C$ and $230^{\circ}C$ for 10 minutes generated 277.06 ppm, 264.81 ppm in pyrazine and 15.16 ppm, 13.19 ppm in thiazole, respectively. The sensory evaluation of oil samples was also investigated. The sesame oil obtained from the sesame seeds roasted at $200^{\circ}C$ for 10 minutes with electric pan showed good flavor scores and quality among the all of samples.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2001.10a
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• pp.140-140
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• 2001

A sensitive analytical method based on gas chromatograpy-mass spectrometry with a selected ion monitoring (GC/MS-SIM) with the purge-and-trap concentration and with headspace method (in limited applications) was developed for determining of epichlorohydrin in canned beverages coated with epoxy resin. The calibration curve in the range of $0.5\sim50ng$ had correlation coefficient greater than 0.998 and a detection limit of $0.l\mug/L$ was obtained using a sample volume of 20ml. The predominant ions of epichlorohydrin produced in MSD using electron ionization(EI) were m/z 57 ([M-CI]+) and 62/64 $([M-CH_2O]+)$. In survey of epichlorohydrin in thirty commercial canned beverage samples, none of them was detected.

• Journal of Korean Society on Water Environment
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• v.21 no.6
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• pp.549-563
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• 2005

The study was carried out to develop and standardize the analytical method of 1,4-dioxane in water. The National Institute of Environmental Research in Korea has monitored for 1,4-dioxane in water since 1998 and it has been detected in environmental water occasionally. But the environmental pollution and analytical method in water is not well known over the world. The trace analytical method at low-${\mu}/L$ level is prerequisite in order to evaluate the residue of 1,4-dioxane in water. Evaluation of the method was demonstrated by comparing and analyzing with liquid-liquid extraction, solid-phase extraction and purge & trap technique. As a result of experiment by standard solutions and raw samples, the precision and accuracy for three methods were obtained within error rate of about 10%. Therefore, three methods were standardized as official monitoring method in Korea. Also, a convenient and simple liquid-liquid extraction method for the analysis of 1,4-dioxane in water was developed by combined with gas chromatography/mass spectrometry and applied to the water samples in Korea

• Clean Technology
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• v.4 no.1
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• pp.35-44
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• 1998

Photodecomposition behaviors of volatile organic compounds (VOCs ; benzene, toluene, ethylbenzene and xylenes) over UV irradiation and UV irradiation with $TiO_2$ powder catalyst were studied and the extent of degradation were also investigated under various reaction conditions. The reactions were conducted in a quartz annular reactor equipped with a medium pressure mercury lamp. As a result, the extents of degradation were 92% for toluene and ethylbenzene, 83% for benzene, and 82% for xylenes under UV irradiation. And they were 92% for toluene, 82% for xylene and ethylbenzene, and 53% for benzene under UV irradiation with $TiO_2$ powder. Analyses of reacted samples by FID-gas chromatograph with Purge & Trap concentrator and GC-MS indicated that the aromatics formed many intermediates.

• Journal of Soil and Groundwater Environment
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• v.7 no.2
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• pp.3-11
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• 2002

The objective of this study was to survey the oil contamination around the Mountain Baegun at Uiwang city to obtain the preliminary data for bioremediation. For measuring the oil concentrations and physical properties from soil, we analyzed BTEX. TPH and pH, organic content, water content, pormeability coefficient, gravity, porosity and used the purge & trap method for analyzing BTEX. Using the Accelerated Solvent Extractor, we pretreated the samples and then analyzed TPH using GC-FID as soon as possible. From the analysis results, maximum concentration of TPH was 24.773mg/kg and BTEX was 101.7mg/kg. The results of TPH at the Mountain Baegun were higher than the enforcement standard of soil contamination(Korea) and the BTEX concentrations were also higher than the advisory standard of soil contamination(Korea). From these results, the Mountain Baegun may requires to remedy the oil-contaminated soil. In addition, we performed the field bioremediation test for five weeks at the Mountain Baegun using the microbial additives that were developed by our laboratory. From the results of the field test, we could find the about 95% of the oil was removed from the contaminated soil in five weeks. So we consider that it is the one of the useful solutions to remedy the oil-polluted site.

• Korean Journal of Microbiology
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• v.36 no.1
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• pp.52-57
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• 2000

A method for quantitative and qualitative analysis of geosmin, odorant produced by several actinomycetes and cyanobacteria, was established and optimized. The effects of environmental conditions on the growth of Phormidium sp. NIVA-CYA7 were examined and the production and release of geosmin by the species was analyzed by using the purge and trap-gas chromatographic technique. One of the major advantages of the technique established in the present study is that the preparation of sample is simpler and purge time is shorter. Under the culture conditions (pH 7.9, $20^{\circ}C$, 120-140 $\mu$E/$m^2$/s and Z8 medium), Phormidium showed growth characteristics with a lag phase for 8 days and an exponential phase for 14 days followed by a stationary phase. Reduction of inorganic nitrogen concentrations in the culture medium from 250 to 100 or 25 $\mu$M brought no significant effect on the cell growth. However, the cell growth was significantly inhibited with decreasing concentrations of inorganic phosphorus from 25 to 10 or 2.5 $\mu$M. When the inorganic phosphorus concentration in the medium was lowered from 25 to 10 $\mu$M, the levels of geosmin in the organism expressed as percentages per unit TOC and chlorophyII-$\alpha$ increased by 35% and 68%, respectively. When the initial pH of the medium was 9.4, geosmin content was 0.0824 $\mu$g/mg C, which was 2-fold higher than that at pH 7.9 Consequently, the level of geosmin in Phormidium was found to vary with growth phases of the culture, external inorganic phosphorus concentration and external pH, while the release of geosmin was not significantly affected by the factors.

• The Korean Journal of Food And Nutrition
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• v.12 no.4
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• pp.375-379
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• 1999

Volatile components of Cornsilk(Zea mays L.) were isolated by purge and trap headspace method and were analyzed by GC and GC/MSD. A total of 44 components were identified in the cornsilk volatile coponents including 9 alcohols 7 aldehydes and ketones 14 terpenes and terpene alcohols 3 pyrazines 5 hydrocarbons and 6 miscellaneous components. The major components were 2-propanol(8.08%) pen-tanol(1.82%) hexanol(2.86%) hexanal(3.68%) heptanal(7.40%) nonanal(7.93%) decanal (2.04%) $\alpha$-copaene(2.20%) limonene(1.68%) $\alpha$-selinene(1.03%) $\beta$-selinene(1.03%)

• Korean Journal of Food Science and Technology
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• v.28 no.4
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• pp.772-778
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• 1996

In order to investigate changes of flavor during food sterilization in retortable pluches, a model food system consisting of 50% chicken breast meat, 1% salt and 49% chicken stock was analyzed before and after retorting using GC and GC-MS. In the analysis of the volatile components collected by the nitrogen purge and trap technique before and after retorting, a total of 53 peaks were observed on chromatograms and 42 peaks were identified. Among the 42 peaks identified were 17 caused by aldehydes, 9 by hydrocarbons, 8 by alcohols, 6 by ketones, 1 by furan and 1 by terpene. Analysis of the data obtained from our model food system strongly suggested that the compounds responsible for retort flavor are 2-heptanone, 2-pentyl furan and various ketones.

• Journal of Environmental Health Sciences
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• v.18 no.2
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• pp.82-91
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• 1992

The examination of the pollutants originated from domestic sewage, industrial and agricutural activities the existences of some toxic heavy metals, organic matters and pathogenic microorganisms. A recent report of WHO brought out that such pollutants are in existence with above roughly 2,000 kinds of chemical substances and amongst them about 750 chemicals have been indentified by drinking water. And above 600 kinds of them are organic pollutants and in addition these include carcinogenic mutagenic and poisonous substances. This is not intended to embody a study of broad confined to various approaches on organic materials, and therefore will be THM produced on injection of chlorine at water filtration plant. To specify the relations between THM and factors having an effect upon THM such as TOC, Cl$_{2}$, Temperature, pH and reaction time, first of all the recovery ratio for analytical methods of THM (Head sapce, purge and trap, Liquid/ Liquid Extraction methods) was investigated. Provided that by using it,the correction coefficients are obtained, the accuracy of data might be able to be enhanced through analysis.The result of the experiments are given in the followings. 1) Among three kinds of analytical methods, recovery rate was higher in order of purge and trap Liquid/Liquid Extraction, Head space. There is no great difference in recovery rate among three methods. 2) The higher the concentration of TOC, the more the amount of THM. 3) The higher the reaction temperature, the more the amount of THM. 4) The longer the reaction time, the more the amount of THM. 5) The higher the pH, the more the amount of THM. 6) The higher the concectration of chlorine, the more the amount of THM.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.7
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• pp.965-970
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• 2003

This study has been performed to develope a method for the simultaneous determination of 1,4-dioxane (DOX), epichlorohydrin (EPC), propylene chlorohydrin (PCH), ethylene chlorohydrin (ECH) and 1,3-dichloro-2-pro-panol (DCP) in polysorbates, chloline chloride, choline bitartrate, modified starch and spices by purge and trapgas chromatography. Experimental design was used to select a suitable trap by measuring the limit of detection (LOD) and to investigate the effect of temperature and salt of extraction, and the percentage of recovery in various matrix. The LOD of DOX, EPC, PCH, ECH and DCP were 1.38$\mu\textrm{g}$, 0.23$\mu\textrm{g}$, 3.30$\mu\textrm{g}$, 3.97$\mu\textrm{g}$, 20.43$\mu\textrm{g}$ respectively, by means of using Vorcarb 3000 trap with 5$0^{\circ}C$ sample sparger. Excluding EPC, the recoveries of target compounds were above 90% in all matrix. Target compounds in polysorbates (17), choline chloride (5), choline bitartrate (5), modified starch (8) and spices (25) were not detected. But 2.5 ppm of DOX was detected in Tween 80.