• Bulletin of the Korean Chemical Society
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• 제27권2호
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• pp.231-236
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• 2006

A novel sample pretreatment technique, headspace hanging drop liquid phase microextraction (HS-LPME) was studied and applied to the determination of flavors from solid clove buds by gas chromatography-mass spectrometry (GC-MS). Several parameters affecting on HS-LPME such as organic solvent drop volume, extraction time, extraction temperature and phase ratio were investigated. 1-Octanol was selected as the extracting solvent, drop size was fixed to 0.6 $\mu$L. 60 min extraction time at 25 ${^{\circ}C}$ was chosen. HS-LPME has the good efficiency demonstrated by the higher partition equilibrium constant ($K_{lh}$) values and concentration factor (CF) values. The limits of detection (LOD) were 1.5-3.2 ng. The amounts of eugenol, $\beta$-caryophyllene and eugenol acetate from the clove bud sample were 1.90 mg/g, 1.47 mg/g and 7.0 mg/g, respectively. This hanging drop based method is a simple, fast and easy sample enrichment technique using minimal solvent. HSLPME is an alternative sample preparation method for the analysis of volatile aroma compounds by GC-MS.

• Food Science and Biotechnology
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• 제18권3호
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• pp.700-705
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• 2009

In this study, the volatile compounds in 9 commercial fermented soybean pastes were extracted and analyzed by headspace-solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS), respectively. A total of 63 volatile components, including 21 esters, 7 alcohols, 7 acids, 8 pyrazines, 5 volatile phenols, 3 ketones, 6 aldehydes, and 6 miscellaneous compounds, were identified. Esters, acids, and pyrazines were the largest groups among the quantified volatiles. About 50% of the total quantified volatile material was contributed by 5 compounds in 9 soybean paste samples; ethyl hexadecanoate, acetic acid, butanoic acid, 2/3-methyl butanoic acid, and tetramethyl-pyrazine. Three samples (CJW, SIN, and HAE) made by Aspergillus oryzae inoculation showed similar volatile patterns as shown in principal component analyses to GC-MS data sets, which showed higher levels in ethyl esters and 2-methoxy-4-vinylphenol. Traditional fermented soybean pastes showed overall higher levels in pyrazines and acids contents.

• Fisheries and Aquatic Sciences
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• 제17권2호
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• pp.189-195
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• 2014

Headspace volatile compounds of cold-stored and freeze-dried Krill Eupausia superba were analyzed to investigate their flavor qualities using a system combining a dynamic headspace isolator, an automatic thermal desorber, and a gas chromatograph-mass-selective detector. Levels of oxidation products of polyunsaturated fatty acids such as aldehydes, alcohols, and ketones, which are known to give seafood a nasty smell because of their low flavor threshold values, increased during cold storage of krill. Notably, levels of 2-methylpropanal, 3-methylbutanal, 2-methylbutanal and 2-butanone increased during its storage. They can be considered index compounds of off-odor according to freshness degradation during storage. By contrast, in freeze-dried krill powder, levels of aldehydes, ketones, and aromatic compounds decreased rapidly. Only alcohols, which did not greatly affect the food flavor, were isolated in large amounts. It was confirmed that levels of oxidized compounds of krill increased during cold storage, but decreased in freeze-dried krill.

• 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).

• 분석과학
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• 제13권3호
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• pp.277-281
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• 2000

16종의 휘발성 유기화합물을 blank water에 첨가하고 고정상으로 $100{\mu}m$ polydimethyl siloxane을 입힌 solid phase microextraction(SPME) fiber를 사용하는 headspace SPME방법으로 추출하여 gas chromatography/mass spectrometry (GC/MS)로 분석하였다. 이 방법의 평균회수율은 97%, 평균상대표준편차는 4.7%, 그리고 검출한계는 $0.01-0.5{\mu}g/l$를 나타냈다. 즉 SPME 방법을 이용한 수용액 중의 휘발성 유기화합물의 결과는 현재 많이 사용되고 있는 기존의 다른 방법보다 우수하고 편리한 방법으로 나타났다.

• Food Science and Biotechnology
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• 제14권4호
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• pp.456-460
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• 2005

To enforce the maximum residue limit for residual hexane (0.005 g/kg) in commercially available Korean vegetable oil, convenient and accurate quantification methods were investigated. Using dual surrogate standards, pentane and heptane were dissolved in ethanol, and then added to hexane-tree sunflower oil for setting up the calibration curve. Gas Chromatograph-Flame Ionization Detector with a porous layer open tubular column, indicated good chromatographic separation of hexane from other inhibiting matrix components. The lowest calibration level was $0.5\;{\mu}g/g$, not exceeding a relative standard deviation of 10% (RSD%), and 1.0\;{\mu}g/g$ not exceeding a deviation of 22% RSD% using heptane as an internal standard for the Static headspace analysis by using a headspace auto-sampler and manual injection, respectively. The residual hexane was detected in nine of the samples among 87 vegetable oil samples purchased on the local market.

• Preventive Nutrition and Food Science
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• 제8권4호
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• pp.315-320
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• 2003

Headspace volatile compounds of oxidized fish oil were analyzed by the combination of hexane solvent or solid phase microextraction, gas chromatography and mass selective detector. The optimum condition of headspace analysis by hexane trapping was 23 min absorption time, 96$^{\circ}C$ sample temperature and 20 mL/min air flow rate. The numbers of volatile compounds identified by solvent trapping and SPME were 35 and 14, respectively. Groups having the largest amount and many kinds were hydrocarbons and aldehydes, respectively. The numbers of aldehydes were 15 and 6 for solvent trap and SPME, respectively. These basic data could be used as indicators for the quality changes of fish oil.

• Elastomers and Composites
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• 제54권3호
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• pp.188-200
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• 2019

Rubber articles contain various organic additives such as antidegradants, curing agents, and processing aids. It is important to extract and analyze these organic additives. In this paper, various extraction methods of organic additives present in rubber composites were introduced (solvent extraction, Soxhlet extraction, headspace extraction, and solid-phase microextraction), and the extracts were characterized using gas chromatography/mass spectrometry (GC/MS). Solvent and Soxhlet extractions are easy-to-perform and commonly used methods. Efficiency of solvent extraction varies according to the type of solvent used and the extraction conditions. Soxhlet extraction requires a large volume of solvent. Headspace sampling is suitable for extracting volatile organic compounds, while solid-phase extraction is suitable for extracting specific chemicals. GC/MS is generally used for characterizing the extract of a rubber composite because most components of the extract are volatile and have low molecular weights. Identification methods of chemical structures of the components separated by GC column were also introduced.

• 한국식품과학회지
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• 제37권5호
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• pp.695-701
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• 2005

각각의 황 함유 화합물의 표준곡선을 그렸을 때, linear range의 범위는 $10^2$부터 $10^4$까지의 범위를 보였다. Dimethyl trisulfide가 가장 작은 limit of detection(LOD) 값과 가장 넓은 linear range $(10^4)$를 보이는 반면, methional은 가장 큰 LOD 값과 가장 좁은 linear range$(10^2)$를 가졌다. 각 황 함유 화학물의 분자구조와 PFPD의 황 함유 화합물 분석 원칙에 영향을 받는 것으로 사료된다. 서로 다른 세 종류의 fiber를 사용시, 미세 고체상 추출법(SPME)을 사용했을 때, CAR/PDMS fiber는 가장 좋은 추출 효율을 보였고, 반대로 PDMS/DVB fiber는 가장 낮은 효율을 나타내었다. SPME 방법을 사용하면, 시료에 포함되어 있는 6개의 황 함유 화합물들 중, 최대 5개까지 분석이 가능하였다. 그러나 본 실험에서 사용하지 않은 황 함유 화합물들도 다수 동정 되었는데, 이렇게 추출과정 중 artifacts로 생성된 황 함유 화합물들은 분석 시 오차를 작용할 수 있다. 고정상 기체추출법(SH)은 SPME와 비교했을 때 더 적은 수의 황 함유 화합물을 감지해냈다. SPME와 비교 시 SH의 추출 효율은 낮았지만, artifact로 생성되는 화합물의 수는 적었다.

• 한국식품영양과학회지
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• 제31권1호
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• pp.26-31
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• 2002

Pinus densiflora(2엽송) 1년생을 채취하여 가지, 잎, 새순 부분으로 구분하고, 시료병에 넣어 밀봉한 뒤, solide phase microextraction (SPME)과 dynamic headspace analysis(DHA)를 이용하여 휘발성 성분을 분리, 동정하였다. SPME와 DHA의 결과를 terpenes의 구성 성분에 따라 monoterpenes과 sesquiterpenes, oxygenated terpenes으로 나누어 조성비를 살펴보면, monoterpenes의 조성은 잎의 경우 각각 66.7%와 14.3%, 새순은 90.6%와 0.7%, 가지에서는 90.6%와 1.2%로 나타났다. Sesquiterpenes의 함량은 SPMe의 결과에서만, 잎이 25.8%, 가지 4.4%, 새순 1.5%로 나타났다. 산소를 함유하고 있는 terpenes의 함량은 새순 부위가 4.7%, 79.0%로 나타났으며, 가지 부위는 3.7%와 70.4%, 잎에서 1.0%와 50.7%를 각각 차지하였다. SPME의 결과는 이전의 용매추출을 통한 결과와 다소 비슷한 양상을 보였으며, DHA의 결과는 10$0^{\circ}C$이상의 고비점 화합물들이 나타나지 않은 반면, 5$0^{\circ}C$이하의 저비점 화합물이 15개 분리되었다.