• Journal of the Korean Wood Science and Technology
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• v.48 no.5
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• pp.591-607
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• 2020

This study was aimed to investigate the changes of chemical composition of the volatile organic compounds (VOCs) emitted from red pine needles in the process of needle abscission or senescence. The VOCs in intact, senescent, and litter red pine needle samples were analyzed by headspace-solid phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC/MS). And then, multivariate statistical interpretation of the processed data sets was conducted to investigate similarities and dissimilarities of the needle samples. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were used to investigate the dataset structure and discrimination between samples, respectively. From the data preview, the levels of major components of VOCs from needles were not significantly different between needle samples. By PCA investigation, the data reduction according to classification based on the chlorophyll a / chlorophyll b (Ca/Cb) ratio were found to be ideal for differentiating intact, senescent, and litter needles. The following OPLS-DA taking Ca/Cb ratio as y-variables showed that needle samples were well grouped on score plot and had the significant discriminant compounds, respectively. Several compounds had significantly correlated with Ca/Cb ratio in a bivariate correlation analysis. Notably, the litter needles had a higher content of oxidized compounds than the intact needles. In summary, we found that chemical compositions of VOCs between intact, senescent, and litter needles are different each other and several compounds reflect characteristic of needle.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.2
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• pp.121-126
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• 2019

Trimethylamine (TMA) is a nitrogen-based aliphatic organic compound. It is a major odorous component of fish and fishery products and is often used as an indicator of fish quality. The efficacy of TMA removal by various yeast strains was investigated. The five yeast strains found to be most effective in removing TMA were isolated from fermented foods and were identified as Saccharomyces cerevisiae based on biochemical and 18S rRNA sequence analyses. These strains were designated as S. cerevisiae SK1511, SK1512, SK1513, SK1514 and SK1515. Yeast cultures were treated with a TMA solution (0.3%, v/v), and the level of TMA reduction was analyzed by headspace gas chromatography. The five S. cerevisiae strains removed 32.02-50.34% of the TMA from the solution. This study is the first to demonstrate TMA reduction by microbial treatment.

• The Plant Pathology Journal
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• v.35 no.5
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• pp.425-436
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• 2019

Botrytis cinerea, a major phytopathogenic fungus, has been reported to infect more than 200 crop species worldwide, and it causes massive losses in yield. The aim of this study was to evaluate the inhibitory abilities and effects of Bacillus amyloliquefaciens RS-25, Bacillus licheniformis MG-4, Bacillus subtilis Z-14, and Bacillus subtilis Pnf-4 and their culture filtrates and extracts against the gray mold caused by B. cinerea on postharvest tomato, strawberry, and grapefruit. The results revealed that the cells of Z-14, culture filtrate of RS-25, and cells of Z-14 showed the strongest biocontrol activity against the gray mold on the strawberry, grape, and tomato fruit, respectively. All the strains produced volatile organic compounds (VOCs), and the VOCs of Pnf-4 displayed the highest inhibition values. Based on headspace solid-phase microextraction in combination with gas chromatography-mass spectrometry, esters accounted for the largest percentage of the VOCs produced by RS-25, MG-4, Z-14, and Pnf-4 (36.80%, 29.58%, 30.78%, and 36.26%, respectively). All the strains showed potent cellulase and protease activities, but no chitinase activity. RS-25, Z-14, and MG-4, but not Pnf-4, grew on chrome azurol S agar, and an orange halo was formed around the colonies. All the strains showed biofilm formation, fruit colonization, and lipopeptide production, which may be the main modes of action of the antagonists against B. cinerea on the fruit. This study provides the basis for developing natural biocontrol agents against the gray mold caused by B. cinerea on postharvest fruit.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.109-109
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• 2020

꽃차(Flower tea)는 최근 다양한 제품이 개발되고 소비가 확대되는 등 그 산업적 가치가 증대하고 있다. 꽃차의 향기 특성은 우렸을 때 나타나는 색깔 및 인체에서의 생리활성과 더불어 주요한 꽃차 품질결정 요소이다. 본 연구는 꽃차로의 이용이 활발한 국화과 식물 중 구절초(Dendranthema zawadskii var. latilobum), 국화(Chrysanthemum morifolium), 노랑색 및 주황색 마리골드(Tagetes erecta 'Yellow' and 'Orange'), 그리고 캐모마일(Matricaria chamomilla)의 향기 성분특성을 구명하기 위하여 제조된 꽃차를 headspace-solidphase microextraction/gas chromatography-mass spectrometry (HS-SPME/GC-MS)를 이용하여 분리, 동정하였다. 국화과 꽃차로부터 총 117종의 휘발성 성분이 확인되었는데, 각 꽃차 종류별 동정된 휘발성 성분의 개수, 주요 3개 휘발성 성분과 전체 향기성분 peak중 이들이 차지하는 구성비율(%)은 다음과 같았다: 구절초 64종, camphor (31%), α-pinene(14%), camphene(14%); 국화 60종, camphor(15%), chrysantheny acetate(13%), eucalyptol (11%); 마리골드 '옐로우' 53종, 2,4-heptadienal(26%), trans-isocarveol(21%), cis-β-Copaene(18%); 마리골드 '오렌지' 61종, β-caryophyllene(16%), β-ocimene epoxide(12%), β-ocimene(12%); 캐모마일 50종, β-farnesene(63%), nonane(9%), spathulenol(5%). 국화과 꽃차 5종 모두에서 공통적으로 검출된 성분은 β-caryophyllene, α-pinene, β-farnesene 등 10종이었으며 마리골리 '옐로'는 '오렌지'와 주요 향기성분의 조성에서 뚜렷한 차이를 나타내었다. 비록 그 함량은 낮았으나 구절초, 국화, 마리골드 '오렌지', 그리고 캐모마일은 각각 10종, 12종, 3종 및 13종이었다. 마리골드 '엘로'의 경우 검출된 모든 향기성분은 마리골드 '오렌지'나 다른 국화과 식물의 꽃차에서도 검출된 바, 향기 성분이 다양성이 다소 낮게 나타났다.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.110-110
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• 2020

꽃을 우려내어 차로 마시는 꽃차(flower tea)는 꽃이 가진 색과 향, 맛과 모양을 즐길 수 있어 최근 수요가 급증하고 있다. 본 연구는 매화(Prunus mume), 장미(Rosa spp.), 그리고 해당화(Rosa rugosa) 등 3종의 장미과 식물의 꽃차의 향기 성분 특성을 구명코자 꽃차를 headspace vial에 담은 후 solid phase microextraction(SPME)를 이용하여 추출한 후 gas chromatography-mass spectrometry를 이용하여 휘발성 성분을 분리하였다. 분리된 각 성분은 deconvolution 과정을 수행한 후 NIST masss spectral library를 이용하여 동정하였다. 매화꽃차에서는 총 58개의 휘발성 성분이 검출되었는데, benzaldehye와 nonane, 그리고 phenylmethanol이 주요 구성 성분으로 검출된 전체 휘발성 성분의 각각 64.7%, 16.1% 및 4.7%를 차지하고 있었다. 장미 꽃차의 경우 검출된 35종 중 주요 구성 성분은 nonane과 2-phenylethanol, 그리고 phenylmethanol로서 각각 전체 성분 중 54.0%, 18.0% 및 4.6%를 구성하고 있었다. 해당화 꽃차의 경우는 장미 꽃차와 동일하게 2-phenylethanol(62.2%)과 nonane(20.1%)이 주요 성분으로 동정되었으며 이들 2 성분의 합이 전체 43개 휘발성 성분의 82.3%를 차지하는 것으로 나타났다. 본 연구에 사용된 매화, 장미, 해당화 등 장미과 식물 3종의 꽃차 모두에서 공통적으로 검출된 휘발성 성분은 앞서 각 꽃차 종류별 주요 성분으로 언급된 4종의 성분을 포함하여 19종이었으며 매화꽃차에서만 검출된 성분은 29종으로 장미꽃차(6종)와 해당화 꽃차(8종)보다 향기성분의 다양성이 높은 것으로 나타났다.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.1
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• pp.27-35
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• 2014

The headspace solid-phase microextraction (HS-SPME) followed by gas chromatography/mass spectrometry procedure has been developed for the simultaneous determination of petroleum aromatic hydrocarbons such as benzene, toluene, ethylbenzene and xylene isomers (BTEX) and polycyclic aromatic hydrocarbons (PAHs) in seawater. The advantages of SPME compared to traditional methods of sample preparation are ease of operation, reuse of fiber, portable system, minimal contamination and loss of the sample during transport and storage. SPME fiber, extraction time, temperature, stirring speed, and GC desorption time were key extraction parameters considered in this study. Among three kinds of SPME fibers, i.e., PDMS ($100{\mu}m$), CAR/PDMS ($75{\mu}m$), and PDMS/DVB ($65{\mu}m$), a $65{\mu}m$ PDMS/DVB fiber showed the most optimal extraction efficiencies covering molecular weight ranging from 78 to 202. Other extraction parameters were set up using $65{\mu}m$ PDMS/DVB. The final optimized extraction conditions were extraction time (60 min), extraction temperature (50), stirring speed (750 rpm) and GC desorption time (3 min). When applied to artificially contaminated seawater like water accommodated fraction, our optimized HS-SPME-GC/MS showed comparable performances with other conventional method. The proposed protocol can be an attractive alternative to analysis of BTEX and PAHs in seawater.

• Analytical Science and Technology
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• v.34 no.1
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• pp.23-35
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• 2021

In order to measure the volatile organic compounds (VOCs) of a sample which is too large to use commercially available chamber, a stainless steel vacuum chamber (VC) (with an internal diameter of 205 mm and a height of 50 mm) was manufactured and the temperature of the chamber was controlled using an oven. After concentrating the volatiles of the sample in the chamber by helium gas, it was made possible to remove residual volatile substances present in the chamber under reduced pressure ((2 ± 1) × 10-2 mmHg). The chamber was connected to a purge & trap (P&T) using a 6 port valve to concentrate the VOCs, which were analyzed by gas chromatography-mass spectrometry (GC-MS) after thermal desorption (VC-P&T-GC-MS). Using toluene, the toluene recovery rate of this device was 85 ± 2 %, reproducibility was 5 ± 2 %, and the detection limit was 0.01 ng L-1. The method of removing VOCs remaining in the chamber with helium and the method of removing those with reduced pressure was compared using Korean drinking water regulation (KDWR) VOC Mix A (5 μL of 100 ㎍ mL-1) and butylated hydroxytoluene (BHT, 2 μL of 500 ㎍ mL-1). In case of using helium, which requires a large amount of gas and time, reduced pressure ((2 ± 1) × 10-2 mmHg) only during the GC-MS running time, could remove VOCs and BHT to less than 0.1 % of the original injection concentration. As a result of analyzing volatile substances using VC-P&T-GC-MS of six types of cell phone case, BHT was detected in four types and quantitatively analyzed. Maintaining the chamber at reduced pressure during the GC-MS analysis time eliminated memory effect and did not affect the next sample analysis. The volatile substances in a cell phone case were also analyzed by dynamic headspace (HT3) and GC-MS, and the results of the analysis were compared with those of VC-P&T-GC-MS. Considering the chamber volume and sample weight, the VC-P&T configuration was able to collect volatile substances more efficiently than the HT3. The VC-P&T-GC-MS system is believed to be useful for VOCs measurement of inhomogeneous large sample or devices used inside clean rooms.

• Journal of the Korean earth science society
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• v.34 no.7
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• pp.681-692
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• 2013

We aimed to evaluate the effectiveness of the Giggenbach bottle method and develop the related pretreatment and analytical methods using artificial fumarolic gases. The artificial fumarolic gases were generated by mixing $CO_2$, CO, $H_2S$, $SO_2$, $H_2$, and $CH_4$ gas streams with a $N_2$ stream sparged through an acidic medium containing HCl and HF, with their compositions varied by adjusting the gas flow rates. The resultant fumarolic gases were collected into an evacuated bottle partially filled with a NaOH absorption solution. While non-condensible gases such as CO, $H_2S$, and $CH_4$ accumulated in the headspace of the bottle, acidic components including $CO_2$, $SO_2$, HCl, and HF that were dissolved into the alkaline solution. Like other acidic components, $H_2S$ also dissolved into the solution, but it reacted with dissolved $Cd^{2+}$ to precipitate as CdS when $Cd(CH_3COO)_2$ was added. The non-condensible gases were analyzed on a gas chromatography. Then, CdS precipitates were separated from the alkaline solution by filtration, and they were pretreated with $H_2O_2$ to oxidize CdS-bound sulfide into sulfate. In addition, a portion of the solution was also pretreated with $H_2O_2$ to oxidize sulfite to sulfate. Following the pretreatment, the resultant samples were analyzed for $SO_4^{2-}$, $Cl^-$ and $F^-$ on an ion chromatography. In the meanwhile, dissolved $CO_2$ was analyzed on a total organic carbon-inorganic carbon analyzer without such pretreatment. According to our experimental results, the measured concentrations of the fumarolic gases were shown to be proportional to the gas flow rates, indicating that the Giggenbach bottle method is adequate for monitoring volcanic gas. The pretreatment and analytical methods employed in this study may also enhance the accuracy and reproducibility of the Giggenbach bottle method.

• Applied Biological Chemistry
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• v.51 no.3
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• pp.238-244
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• 2008

The essential oil was obtained from the aerial part of Caryopteris incana Miq. by steam distillation, samples were collected by headspace (HS) and solid-phase microextraction (SPME) methods, and the compositions of the essential oil were analyzed by gas chromatography-mass spectrometry (GCMS). The fragrance of the essential oil was fougere and woody. There were sixty-nine constituents in the essential oil: 28 carbohydrates, 22 alcohols, 7 acetates, 7 ketones, 3 aldehydes, and 2 others. Major constituents were 4,6,6-trimethyl [1S-($1{\alpha},2{\beta},5{\alpha}$)]-bicyclo[3.1.1]hept-3-en-2-ol (11.8%), taucadinol (9.4%), myrtenyl acetate (9.2%), pinocarvone (7.0%), 1-hydroxy-1,7-dimethyl-4-isopropyl-2,7-cyclodecadiene (6.3%), ${\delta}$-3-carene (6.2%). By SPME extraction, forty-nine constituents were identified: 22 hydrocarbons, 16 alcohols, 6 acetates, 3 ketones, and 2 ethers. Major constituents of the SPME-extracted sample were ${\delta}$-3-carene (12.6%), (-)-myrtenyl acetate (11.2%), 6,6-dimethyl-2-methylene-bicycol [3.1.1] heptan-3-o1 (10.9%), pinocarvone (9.3%). By HS extraction, ten constituents were identified: 5 hydrocarbons, 2 amines, 1 alcohol, and 2 others. Major constituents of the HS-extracted sample were (Z)-2-fluoro-2-butene (34.9%), ${\delta}$-3-carene (6.9%), 6-(4-chlorophenul)tetrahydro-2-methyl-2H-1,2-oxazine (5.9%). The $IC_{50}$ value (0.011 ${\mu}g/mg$) in MTT assay using HaCaT keratinocyte cell line was lower than those of commercially-selling rosemary and tea tree, suggesting more toxicological studies are needed for commercial use of the essential oil of Caryopteris incana Miq.

• Korean Journal of Food Science and Technology
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• v.51 no.6
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• pp.543-550
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• 2019

In this study, volatile compounds in 13 aged and 3 commercial rice-distilled soju samples were isolated by headspace solid phase microextraction (HS-SPME) and analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 85 volatile components including 35 esters, 15 alcohols, 5 ketones, 3 aldehydes, 15 miscellaneous, and 14 unknowns were identified. Esters and alcohols were the largest groups among the quantified volatiles. Differences in volatile compounds among the distilled soju samples and possible sample groupings were examined by principal component analysis of the GC-MS datasets. The first and second principal components (PC1 and PC2, respectively) explained 51.94% of the total variation across the 16 samples. The samples aged in oak containers had higher concentrations of ketones, aldehydes, and miscellaneous compounds. In the positive direction of PC1, oak-aged samples were observed, while, pot-aged samples were observed on the far negative side. Furthermore, samples aged for longer periods, such as 18 months, were observed in the positive direction of PC2.