• Journal of Plant Biology
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• 제38권3호
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• pp.219-225
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• 1995

Five kinds of 4-demethylsterol were isolated from suspension cultured cells of a liverworth, Marchantia polymorpha. Four 4-demethylsterols among them were analyzed by a capillary gas chromatography-massspectrometry and 500 MHz 1H-NMR, and characterized to be avenasterol, 24-methylene-cholesterol, stigmasterol, and campesterol. And the fifth 4-demethylsterol was characterized to be sitosterol by a capillary gas chromatography-mass spectrometry. The concentration of the 4-demethylsterols in the cell decreased in order of avenasterol>stigmasterol>24-methylene-cholesterol>campesterol>sitosterol. When carbon skeleton and the oxidation state was compared with those of brassinosteroids, these 4-demethylsterols may be potent biosynthetic procusors of brassinosteroids in the cells.

• 한국식품과학회지
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• 제25권5호
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• pp.494-501
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• 1993

The volatile flavor components of traditional and commercial kochujang were collected by simultaneous steam distillation-extraction (SDE) method. Essential oils were analyzed by gas chromatography (GC) and combined gas chromatography-mass spectrometry (GC/MS). Tested kochujang included Sunchang kochujang prepared with glutinous rice, Boeun kochujang prepared with barley, Sachun kochujang prepared with wheat and commercial kochujang. One hundred and twelve volatile flavor components which included 30 esters, 15 alcohols, 14 aldehydes, 13 acids, 9 ketones, 7 alkenes, 6 phenols, 3 alkanes, 3 pyrazines, 2 benzenes and 2 furans were identified. The major volatile compounds in traditional and commercial kochujang were 2-methyl propanal and ethanol, which represented $21{\sim}36%\;and\;2{\sim}44%$ of total GC peak area, respectively.

• 한국식품과학회지
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• 제22권3호
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• pp.261-265
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• 1990

두충엽의 휘발성 성분을 SDE 장치로 추출한 후 GC 및 GC/MS에 의해서 비교 분석하였다. 확인된 성분은 35개 성분이며 alcohol류 7종, aldehyde류 3종, ketone류 4종, ester류 2종. hydrocarbon류 18종, phenol 1종이 확인되었다. 이 중에서 가장 많이 함유된 성분은 2-ethyl furyl acrolein으로 추정되었는데 전체 휘발성 성분의 31.4%를 차지하였다.

• Applied Biological Chemistry
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• 제20권1호
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• pp.130-135
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• 1977

가스 크로마토와 가스크로마-토질량분석기에 의하여 수종의 수산기 함유 아미노산의 치환에 스터화반응을 고찰하고 이들의 fragmentation기작을 설명 했다.

• 한국식품영양과학회지
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• 제28권2호
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• pp.299-304
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• 1999

To compare the composition of volatile flavor components of two different types of rice, the volatile flavor concentrates isolated from brown rices Hyangnambyeo(aromatic cultivar) and Dongjinbyeo (normal cultivar) were analyzed by gas chromatography and gas chromatography mass spectrometry. A total of components, including 16 hydrocarbons, 16 aldehydes and ketones, 15 alcohols, 4 acids, and 10 miscellaneous components were identified positively or tentat ively. Among them, n pentanol was the most abundant component in both samples and Hyangnambyeo contained more aldehydes and alcohols than Dongjinbyeo. 2 Acetyl 1 pyrroline which is chiefly responsible for the character istic odor of aromatic type rice was high in Hyangnambyeo compare to Dongjinbyeo, but these were detected as minor component.

• Archives of Pharmacal Research
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• 제17권3호
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• pp.175-181
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• 1994

The solid-phase extraction (SPF) with subsequent tert-butyldimethylsilyl (TBDMS) derivatization was investigated for the rapid profiling and screening of various carboxylated non-steroidal antiinflammatory drugs (NSAIDs) simultaneously in biological fluid samples. Compared to the conventional SPF in adsorption mode using Chromosorb 102, Chromosorb 107, Carbopak B and Thermosorb, the SPF in partition mode using Chromosorb P as the adsorbent, and ethyl acetate/methylene chloride as the eluting solvents provided hightest overall recovenies of the NSAIDs from aqueous solutions with good precision. The solid-phase extracted NASIDs were silylated with N-methyl-N-(tert-butyldimethylsily)trifuoroacetamide to TBDMS derivatives and directly analyzed by capillary gas chromatography and gs chromatography-mass spectrometry. The usefulness of the present method was examined for the profilling and screening of saliva, serum and urine samples for various NSAIDs simultaneously.

• Bulletin of the Korean Chemical Society
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• 제34권1호
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• pp.139-142
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• 2013

A study was carried out to evaluate the solid phase micro-extraction (SPME) for formaldehyde emission analysis of uncoated plywood. In SPME, formaldehyde was on-fiber derivatized through headspace extraction and analyzed by gas chromatography coupled with mass spectrometry (GC/MS). The SPME was compared with desiccators (DC-JAS 233), small-scale chamber (SSC-ASTM D6007) and liquid-liquid extraction (LLE-EPA 556) methods which were performed in accordance with their respective standards. Compared to SSC (RSD 4.3%) and LLE (RSD 5.0%), the SPME method showed better repeatability (RSD 1.8%) and not much difference from DC (RSD 1.4%). The SPME has proven to be highly precise (at 95% confidence level) with better recovery (REC 102%). Validation of the SPME method for formaldehyde quantitative analysis was evidenced. In addition, the SPME by air sampling directly from plywood specimens (SPME-W) correlated best with DC ($r^2$ = 0.983), followed by LLE ($r^2$ = 0.950) and SSC ($r^2$ = 0.935).

• Food Science and Biotechnology
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• 제16권1호
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• pp.110-115
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• 2007

In this study we investigated the volatile compounds that are generated in sesame and contribute to its characteristic flavor. Different reaction systems were used to examine how certain amino acids influenced flavor profiles, and also to evaluate the effects of sugar types on the distribution of those volatile compounds. The volatiles that were generated in each reaction system were selectively isolated and analyzed by gas chromatography and gas chromatography-mass spectrometry, respectively. Among the 20 identified compounds, nitrogen-containing alkylpyrazines were found to be the predominant volatiles. The alkylpyrazine amounts varied across the different model systems, with the total yield being highest in the arginine reaction mixture, followed by the alanine, serine, and lysine mixtures. In general, fructose generated the most extensive amount of volatiles compared to glucose and sucrose. However, the yield of specific flavor compounds varied according to the type of sugar used. Finally, the results clearly showed that a reaction temperature of $135^{\circ}C$ and a reaction time of 20 min generated the highest amount of volatile compounds.

• 한국식생활문화학회지
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• 제3권2호
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• pp.207-210
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• 1988

한국산(韓國産) 야생 산채류인 맑은대쑥의 휘발성 풍미성분을 수증기 증류법으로 추출해서 GC와 GC-MS 조합에 의하여 분석하였다. 본 연구에서 hydrocarbons 17종류, alcohols 6종류, aldehydes 2종류, oxide 1종류, 그리고 furans 3종류 등 총 29개의 성분이 확인되었다.

• Environmental Analysis Health and Toxicology
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• 제15권1_2호
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• pp.45-51
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• 2000

Analytical method of 4-nitrotoluene (4-NT) in water was developed by 9as chromatography/mass selective detector/selected ion monitoring (GC/MSD/SIM). 4-NT was extracted with diethyl ether. Organic layer was washed with 5 % sodium chloride solution. The influence of solvent and evaporation condition on extraction of 4-NT were examined. The retention time of 4-NT peak was 7.72 min. Coefficient of variation (CV) of 4-NT (ng) within day and day-to-day was ranged from 7.0 to 14.6% and from 7.7 to 20.8%, respectively. Recovery of 4-NT was ranged from 84 to 109%, and detection limit of 4-H was lese than 1 ng/㎖.