• 한국식품과학회지
• /
• 제30권6호
• /
• pp.1247-1251
• /
• 1998

식초의 에탄올과 초산을 동시에 분석하고자 packed column으로 gas chromatographic analysis을 모색하였다. Tenax-GC를 충진물로 사용하여 $2\;m{\times}2\;mm$의 stainless steel column을 제조하고 식초를 여과하여 column에 직접 주입한 결과 내부 표준 물질로 사용한 isopropyl alcohol과 에탄올, 초산이 20분 이내에서 완전히 분리되었으며 정확도가 매우 높은 것으로(P<0.05)나타났다. 19종의 식초를 이용하여 적정방법으로 산도를, packed column GSC로 에탄올과 초산을, HPLC로 초산을, capillary column GLC로 에탄올과 초산을 각각 분석하여 분석치들을 상호 비교하였다.

• 대한수의학회지
• /
• 제40권1호
• /
• pp.72-80
• /
• 2000

Lipopolysaccharides (LPS) of Pasteurella multocida (P multocida) and several Gram-negative bacterial pathogens were analyzed by methanolysis, trifluoroacetylation and gas chromatography (GC) on a fused-silica capillary column. The GC analysis indicated that LPS prepared from a strain of P multocida by phenol-water (PW) or trichloroacetic acid (TCA) extraction were quite different in chemical composition. However, LPS prepared from Salmonella enteritidis by the two extraction methods were very similar. PW-LPS extracts from different Pasteurella strains of a serotype had essentially identical GC patterns. Endotoxic LPS extracted from 16 different serotypes of P multocida by PW or by phenol-chloroform-petroleum ether procedures yielded chromatograms indicating similar composition of the fatty acid moieties but minor differences in carbohydrate content. When the chemical composition of endotoxic LPS extracted from several Gram-negative bacteria (P multocida, Pasteurella hacmolytica, Haemophilus somnus, Actinobacillus ligniersii, Brucella abortus, Treponema hyodysenteriae, Escherichia coli, Bacteriodes fragilis, Salmonella abortus equi and Salmonella enteritidis) were examined, each bacteria showed a unique GC pattern. The carbohydrate constituents in LPS of various Gram-negative bacteria were quite variable not only in the O-specific polysaccharides but also in the core polysaccharides. The LPS of closely related bacteria shared more fatty acid constituents with each other than with unrelated bacteria.

• Preventive Nutrition and Food Science
• /
• 제1권1호
• /
• pp.127-133
• /
• 1996

The development of high resolution capillary columns and a large variety of different detectors led to a strong position of gas chromatography in instrumental analysis. Every effort has been made to solve sophisticated separation problems by column switching. Nowadays, several systems are commercially available for this purpose. The principle and the capabilities of multidimensional gas chromatography(MDGC) are illustrated by different applications in the field of modern flavor and essential oil research.

• FOCUS: LIFE SCIENCE
• /
• 제1호
• /
• pp.2.1-2.6
• /
• 2024

This article provides detailed instructions for the correct installation, maintenance, and troubleshooting of capillary gas chromatography (GC) columns. It emphasizes the importance of proper installation to ensure optimal performance and longevity of the column. The document covers various aspects such as column trimming, installation, conditioning, testing, storage, and ferrule selection. The installation process involves ensuring that the heated zones of the GC are cool before placing the column cage in the column oven. It is essential to avoid sharp bends or stress on the capillary column during installation and to connect the front end of the column into the GC inlet at the recommended insertion distance. The document also provides guidance on trimming the column, including the use of a ceramic wafer or capillary column cutter to achieve a clean, burr-free cut. For previously used columns, it recommends removing any capillary caps, positioning the nut and ferrule, and trimming 1-2 cm from the column. After installation, the column should be purged with carrier gas to remove any oxygen and avoid oxidizing the column. Conditioning the column involves ramping to the upper isothermal temperature limit and maintaining this temperature for a specified duration. It is crucial to maintain carrier gas flow during conditioning and not exceed the upper temperature limit of the column to avoid phase damage. The document also discusses testing column performance using a suitable method and performing a test injection to assess performance. It provides recommendations for column storage, including flame-sealing the capillary ends or using retention gaps for long-term storage. Additionally, it emphasizes the importance of routine maintenance and replacement of GC consumables to extend the column's lifetime. Ferrule selection is another important aspect covered in the article, with a variety of ferrule materials available for different applications. The characteristics of common ferrule options are presented in a table, including temperature limits, reusability, and suitability for specific detector types.

• 한국환경과학회지
• /
• 제6권2호
• /
• pp.183-187
• /
• 1997

유기인제 농약을 70% acetone으로 추출한 다음 dlchloromethane 층으로 옮겨 추출물을 florisil로 충진된 open-column에서 chromatography를 행하였다. 마지막 추출물을 nitrogen-phosphorus detector(GC/NPD)을 가진 GC로 분석하였다. Narrow-bore capillary GC(Ultra-2)에 대해 18 가지의 유기인제 농약의 회수율이 88.7%에서 100.0%에 달하였다. 본 분석 방법의 최소 검출 준위는 0.019 - 0.035 mg/kg 이었으며 sample throughput(추출, open-column chro-matography 및 GC 분석)도 상당히 개선되었다.(sample당 8시간)

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

• 한국작물학회지
• /
• 제35권2호
• /
• pp.176-178
• /
• 1990

한국에서 자생군락이 비교적 큰 3지역에서 채집한 달맞이꽃 종자의 필수 지방산을 Capillary column gas chromatography로 분석하였다. 각 지방산의 조성 함량은 palmitic acid가 6.19-6. 73%, stearic acid가 1.84-l.99%, oleic acid 가 6.73-9.10%, linoleic acid가 74.41-75.53%이었다. 특히 prostaglandin의 전구체인 GLA는 청주가 9.14%, 제천이 9.32%이고, 안동이 8.31%이었다. 따라서 한국의 자생 달맞이꽃은 GLA자원으로 유용한 것으로 생각된다.

• 한국연초학회지
• /
• 제7권1호
• /
• pp.67-74
• /
• 1985

Cis-trans forms of fatty acids in cigarette smoke condensate were separated and characterized using SP 2340 glass capillary gas chromatography. The transforms of fatty acids, palmitoeladic , 1-vaccenic, eladic and linoeladic acid were identified. These components were not present only 3% of the total fatty acid fraction, but they showed a very low transfer rate.

• 한국식품과학회지
• /
• 제32권5호
• /
• pp.997-1001
• /
• 2000

Gas chromatography를 이용한 profiling과 신속한 동정을 허브류에 존재하는 유기산의 분석에 적용하여 보았다. 흡착제로 Chromosorb P와 용출 용매로 diethyl ether를 사용하는 고체상 추출법을 이용하여 허브추출물로부터 유기산을 분리한 후, tert-butyldimethylsilyl 유도체로 만들어 극성이 다른 DB-5와 DB-17 컬럼으로 동시분석하였다. 두 컬럼에서 분리된 유기산 피크들을 dual capillary column system의 retention index(RI) library 탐색과 RI specta 비교로 신속하고 정확하게 동정할 수 있었으며 이들을 GC-MS로 확인하였다. 허브추출물들의 유기산 분석 결과 fatty acid, dioic acid, hydroxy acid, aromatic acid등 24가지의 유기산이 동정되었고 각 허브의 종류에 따라 특징적인 유기산 GC-profile을 나타내었다. 각 허브추출물의 GC profile의 유기산 조성만을 단순화시킨 RI spectra로 표현한 결과, 각 허브의 유기산 패턴의 분별이 매우 용이하였다.

• 한국대기환경학회:학술대회논문집
• /
• 한국대기환경학회 1988년도 제6회 대기보전학술대회 요지집
• /
• pp.61-61
• /
• 1988