• Food Science and Preservation
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• v.4 no.3
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• pp.295-300
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• 1997

The water extract of mustard seed was fractionated by solvents with an increase of polarity, and antimicrobial activities of each extracts were examined, and volatile compounds of each extract were identified by GC-MS. When the water extract was fractionated with solvents, the antimicrobial activities were high in the order of chloroform, ethylacetate, hexane, butanol and aqueous layer. In chloroform fraction, 16 volatile compounds, including 2 isothiocyanates such as 3-isothiocyanato- 1-propene and 4-isothiocyanato- 1-butane, 1 nitrile and 4 acids were identified, their contents were higher than other fractions. Twelve, 10, 4 and 7 volatile compounds were identified in ethylaceate, hexane, butanol and water fractions, respectively. The volatile compounds were considerably less in the fractions of butanol and water than others.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2008.11a
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• pp.272-274
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• 2008

일반적으로 프탈레이트 에스테르의 전처리방법에는 액액추출법(Liquid Liquid Extraction, LLE), 고상추출법(Solid Phase Extraction, SPE), 고상미세추출법(Solid Phase Micro Extraction, SPME) 등의 분석방법이 있다. 그 중에서 본 연구에서는 간편하고 정확성이 높은 SPE를 이용하였으며, 적은 양의 유기용제를 사용하여 전처리함으로써 2차적인 환경 오염을 줄일 수 있다는 점에서 다른 전처리 방법보다 유용하다고 할 수 있다. 또한 프탈레이트 에스테르의 경우는 구조적으로 안정적인 편이나 페놀류의 경우 hydroxy group 때문에 GC/MS 분석시 유도체화 과정이 필수적이나 이번 연구에서는 HPLC를 이용하므로 별도의 유도체화의 번거로움 없이 바로 분석할 수 있는 이점이 있다. 더 많은 연구가 필요하겠지만 앞서서의 결과에서도 알 수 있듯이 전반적으로 검출한계가 0.1$\sim$0.5$\mu$g/L 정도로 높고, 82% 이상의 양호한 회수율을 나타낸 것으로 미루어 보아 극미량 분석이 아닌 이상, 산업체에서 HPLC의 이용이 더욱 유리할 것이라고 사료된다.

• Journal of Power System Engineering
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• v.11 no.2
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• pp.64-71
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• 2007

The main purpose of this study is to analyze the characteristics of toluene removal by plasma, photocatalyst, and plasma/photocatalyst system with the major parameters such as flow rate, inlet toluene concentration and applied voltage, etc., experimentally. In the combined plasma/photocatalyst process, rates of toluene conversion are represented as 99% at flow rate 250, 500 mL/min while, below 97% at flow rate 1000 mL/min due to the low residence time(reaction time) at the same applied voltage 4173 voltage and toluene inlet concentration 50 ppm. The intermediate products are detected by GC/MS analysis showing the small amounts of benzoic acid, benzyl alcohol and residual ozone concentration $0.04{\sim}0.05$ ppm generated by plasma process in the present system.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2005.05a
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• pp.301-305
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• 2005

3-메틸-1-페닐-2-피라졸린-5-은과 N,N-디에틸-1,4-페닐렌디아민의 반응에서 마젠타 아조메틴색소(M)를 합성하였다. 마젠타 아조메틴 색소는 에탄올, 아세톤, 그리고 클로로포름에 잘 녹는다. 원소분석, 핵자기공명스펙트럼, 적외선 홉수 스펙트럼, 그리고 GC/MS 스펙트럼에서부터 마젠타 아·조메틴 색소임을 확인하였다. 마젠타 아조메틴 색소는 염기성용액에서 분해된다. 에탄을 수용액에서 염기에 의한 마젠타 아조메틴 색소의 퇴색반응을 분광학적인 방법으로 540 nm에서 측정하였다. 그리고 OH$^-$와 H$_{2}$O(11${\sim}$40 M의 범위)의 농도가 증가함에 따라 퇴색반응속도는 증가하였다. 이 반응에 대한 실험속도 식은 다음과 같다. -d[D]/dt = {k$_{OH}$[OH$^-$][H$_{2}$O]}[D] 이 속도식과 일치하는 메커니즘을 제시하였다.

• Journal of Food Hygiene and Safety
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• v.12 no.3
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• pp.210-216
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• 1997

The prevention of oxidative degradation in fats and oils is largely controlled by the use of synthetic phenolic antioxidants. Antioxidants, BHA: 2-&-3-tert-butyl-4-hydroxyanisol, BHT: 3,5-di-tert-butyl-4-hydroxytoluene, TBHQ: tert-butylhydroquinone, PG: propyl gallate, PTG: pentyl gallate, OG:octyl gallate, were extracted from fatty foods with hexane and from hexane layer to presaturated acetonitrile with hexane. The polar phenolic hydroxyl groups of antioxidants were silylated with MSTFA and injected to Gas Chromatography/Mass Spectrometry. The calibration plots were linear in the investigated range, 0.1~10.0 $\mu\textrm{g}$/g. The limit of detection for 6 phenolic antioxidants was 0.1 $\mu\textrm{g}$/g. Recoveries and reproducibilities from samples fortified at 1.0 $\mu\textrm{g}$/g were in the range of 70~90% and 0.5~13%, respectively. The simultaneous determination of phenolic antioxidants in fatty foods using GC/MS-SIM mode and macro program was described.

• Proceedings of the Korean Environmental Health Society Conference
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• 2004.06a
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• pp.169-172
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• 2004

A gas chromatography/mass spectrometric assay method was developed for the determination of propylene oxide adduct, N-(3-hydroxypropyl)valine. Adduct was released from hemoglobin by alkaline hydrolysis and extract at pH 8 with ethyl ether. The dried extract was completely derivatized with N-Methyl-N-(trimethylsilyl) trifluoroacetamide (MSTFA)/TMS-I (100:3). The detection limits of the assay were 0.08 ng/g for N-(3-hydroxypropyl)valine based upon assayed hemoglobin of 0.1 g. The method was applied to the determination of propylene oxide adduct formed in young female Sprague-Dawley rats after treatment for 1, 2 and 3 weeks with 0.008 % propylene oxide via the drinking water. An adduct was detected by proposed procedure. The structure of the adduct could be assigned to N-(3-hydroxypropyl)valine.

• Archives of Pharmacal Research
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• v.19 no.6
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• pp.566-569
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• 1996

A sensitivity method has been developed for the detection and determination of niflmic acid(NA) in human urine. Samples were extracted with diethylether. Flunixin (FN) was added to the sample prior to extraction as an internal standard. Niflumic acid was converted to its methyl derivative and analyzed by capillary gas chromatography/negative chemical isonization mass spectrometry. Using selected ion monitoring (SIM), the levels of NA down to 5 pg/ml could be detected in 5 ml spiked urine sample. Calibration curve was linear over the range of 0.5 ppm-50 ppm. The recovery of niflumic acid from urine at 40 pg/ml was to be $91.7{\pm}3.8(n=3)$ and the coefficient of variation was 4.1%.

• Bulletin of the Korean Chemical Society
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• v.19 no.1
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• pp.45-50
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• 1998

Most organophosphorus pesticides may be metabolized to yield some common phosphates in human or in animals, and these metabolites may be used as the exposure biomarkers to pesticides. In this study, we developed the extraction method of four phosphate metabolites from the spiked human urine in high recovery by the solid phase extraction with a reverse-phase cartridge (cyclohexyl silica) followed by the elution with methanol. The extracted urinary metabolites were derivatized with hexamethyldisilazane/trimethyl-chlorosilane/pyridine (2 : 1 : 10, v/v/v) and identified by gas chromatography/mass spectrometry. Calibration curve obtained from each metabolite standard using by GC/MS/SIM has shown good linearity and detection limits of metabolites were the range of 0.05-0.1 ㎍/㎖ in urine. Phenthoate, one of the organophosphorus pesticides, was orally administrated to rats. Four metabolites were detected in the rat urine. The results of this study may be applied to development of exposure biomarkers for monitoring of environmental pollutants.

• Journal of Food Hygiene and Safety
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• v.5 no.3
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• pp.159-164
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• 1990

To detect and quantitation residual antibiotics and antibacterial agents in meats, we performed a biological assay employing the three microorganisms Bacillus subtilis ATCC 6633, Micrococcus luteus ATCC 9341, and Bacillus cereus var. mycoides ATCC 11778 for the screening purpose and developed a Gas Chromatography-mass Spectrometry(GC/MS) analysis for the confirmation and quantiation. In the biological assay (paper disk method), three test solution are used depending on the character of the residual antibiotics and antibacterial agents, follow by a simple clean up procedure which includes homogenization with Mcilvaine buffer, defatting with includes homogenization with Mcilvaine buffer, defatting with hexane, extraction with chloroform, clean-up by Sep-Pak $C_{18}$ and Bakerbond SPE carboxylic acid column. The chloroform layer is used for the analysis of sulfa agents. macrolides antibiotics and antibacterial agents, Adsorbed materials in the Sep-Pak $C_{18}$ were also employed for th analysis of penicillins and tetracyclines. Effluents from the Sep-Pak $C_{18}$ were cleaned-up one more by Bakerbond 10 SPE COOH column and employed for the analysis of aminoglycosides. In the instrumental analysis by using the GC/MSD, residual antibiotics and antibacterial agent were quantitated by selected ion monitoring (SIM) mode after derivatization. A simultaneous analysis of six residual antibiotic and antibacterial agent such as oxytetracycline, penicillin, ampicillin, choliraphenicol and thiamphenicol was developed with simple cleanup procedures revealing good recovery and reproducibility. Also, simultaneous detection of macrolides antibiotics such as erythromycin, spiramycin, and oleandomycin was developed after acid hydrolysis due to their large molecular structures. Because of the high reproducibility and selectivity of these two methods, it is very desirable that the combination of the two methods be used in the bioassay for the screening of residual antibiotics and antibacterial agent and that GC/MSD analysis be used for the confirmation and quantitation.

• Journal of the Korean Society of Safety
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• v.21 no.6 s.78
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• pp.38-45
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• 2006

Polymeric floorings mainly consisted of PVC are easily decomposed by many kinds of hot environmental factors, then generate hazardous asphyxiate gases and/or toxic gases etc. Therefore the mechanism of decomposition and quantitative toxic indices of products are very important for preventing safety and health disasters, especially in case of confined area. So we have investigated decomposition kinetics, numbers of process involved, toxicity indices of product and so on, using DSC, TGA, FT-IR and Pyrolyzer-GC/MS. The thermal decomposition process of polymeric floorings can be mainly divided by dehydrochlorinated reaction and polyene decomposition step, and activation energies of those are approximately $53.93{\sim}62.42kcal/mol$. Especially lethal concentration($LC_{50}$), fractional effective dose (FED) are calculated by measuring the amount of decomposition product. The values on $LC_{50}$ of sample G are ranged $2,003{\sim}2,019(mg/m^{3})$ in case of sample K and H are $1,877,\;1,998(g/m^{3})$ respectively. Even if the results are estimated by calculation method without animal test and/or clinical demonstration, these values could be very useful data for occupational health, hygiene and safety control.