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

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

• 대한수의학회지
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• 제40권1호
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• pp.72-80
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• 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.

• 한국환경과학회지
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• 제6권2호
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• pp.183-187
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• 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)

• Bulletin of the Korean Chemical Society
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• 제14권2호
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• pp.250-255
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• 1993

A dual capillary column system is described for the simultaneous analysis of a given sample and measurement of retention index (RI) and area ratio (AR) values of each peak on two capillary columns of different polarity, DB-5 & DB-1701 from a single injection. Both capillary columns were connected to either a splitless injector or an on-column injector via a deactivated fused-silica capillary tubing of 1 m length and a 'Y' splitter. Both injection modes allowed to measure RI and AR values with high reproducibility (<0.01% RSD) and high accuracy (<10% RE), respectively with the exception that the trace and high boiling solutes required the on-column mode for the accurate quantification and AR comparison. When the dual capillary column system in on-column injection mode was applied to the blind samples containing organic acids, each acid was positively indentified by the combined computer RI library search-AR comparison.

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

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2005년도 추계 학술대회논문집
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• pp.21-26
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• 2005

Gas Chromatography (GC) is a wisely technique used for the separation and analysis of liquid and gas sample. Separation of the sample vapors is achieved via their differential migration through a capillary column with an insert carrier gas. The identity and quantity of each vapor in the mixer can be determined from its retention time in the column and a particular property of the gas, such as thermal conductivity, which can be related to the concentration of sample vapor in the carrier gas. Therefore, the flow characteristics in the spiral gas chromatographic column are numerically investigated in this study. Especially, different pressure drop between the front and the rear of GC column with various flow rates is estimated the governing equations are derived from making using of three-dimensional Naver-Stokes equation with incompressible and laminar model due to the nature of low Reynolds number flow. Using a commercial code, FLUENT, the pressure and flow fields in GC column are calculated with various flow rates. The characteristics of thermal cycling which is one of the most important factors affecting the column efficiency and analysis time is also estimated. Furthermore, numerical analyses are also carried out by using commercial code, ANSYS, with various values of power, which is applied to the heating element located at lower GC column.

• 대한화학회지
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• 제31권5호
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• pp.425-433
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• 1987

모세관 컬럼을 사용한 기체크로마토그래피로 19종 유기염소제 농약의 분리를 검토하였고, 쌀에 첨가한 농약들의 회수율을 구하여 봄으로써 실제분석에 대한 본 방법의 응용 가능성을 조사하였다. SE-30과 OV-17모세관 컬럼의 분리를 비교하여 본 결과 OV-17 컬럼(25m ${\times}$ 0.20mm, 0.27${\mu}$m 두께)으로 분리가 잘되고 있으며, splitless방식으로 주입한 농약들의 머무른 시간과 봉우리 면적에 대한 상대표준 편차가 최대로 0.16%와 8.2%이었다. 쌀에 첨가된 농약의 회수율은 대부분 85%이상이었고 분석 결과에 대한 상대표준편차가 가장 큰 것이 11.4%로서 흔적량의 잔류농약분석에서 비교적 정밀도가 좋음을 확인하였다.

• 한국작물학회지
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• 제35권2호
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• pp.176-178
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• 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.

• 대한화학회지
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• 제38권2호
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• pp.151-159
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• 1994

기체시료 채취기와 짧은 모세관 컬럼(내경 0.32 mm, 길이 3 m), 광이온화 검출기 및 진공펌프로 구성되어, 컬럼의 출구 압력이 대기압보다 낮은 압력에서 조작되는 휴대용 기체 크로마토그래피 시스템을 개발하였다. 컬럼의 규격은 Golay식을 이용한 계산 결과를 기초로 선택하였으며, 조작압력비(컬럼입구와 출구압력비)는 1.03~1.2의 범위가 적절하였고, 이 조건에서 0.87∼4.63 ml/min의 걸럼유량을 얻을 수 있었다. 구경이 다른 3개의 튜브로 구성된 기체시료 채취기는 자동으로 기체시료를 직접 컬럼에 빠른 속도로 반복하여 도입할 수 있으며, 좋은 재현성을 나타내었다. 컬럼출구 압력이 대기압 이하에서 조작되며 짧은 모세관 컬럼을 사용하는 기체 크로마토그래피는 최적 컬럼유량이 일반적인 크로마토그래피보다 커 신속한 분석이 가능하여, 40초 이내에 m-xylene 과 o-xylene의 바탕선 분리가 가능하였다. 시스템의 분리능력에 영향을 주는 인자는 시료 채취시간, 컬럼의 길이와 내경 및 조작압력비였고, 벤젠 유도체들을 사용하여 이들의 영향을 검토하였다.