• Bulletin of the Korean Chemical Society
• /
• 제31권10호
• /
• pp.2791-2796
• /
• 2010

In the present study, we constructed a membrane inlet assembly for selective permeation of volatile airborne organic compounds for subsequent analysis by time-of-flight mass spectrometry. The time-dependent diffusion of analytes through a $75\;{\mu}m$ thick polydimethylsiloxane membrane was measured by monitoring the ion signal after a step change in the sample concentration. The results fit well to a non-steady-state permeation equation. The diffusion coefficient, response time, and sensitivity were determined experimentally for a range of polar (halogenated) and nonpolar (aromatic) compounds. We found that the response times for several volatile organic compounds were greatly influenced by the alkyl chain length as well as the size of the substituted halogen atoms. The detection limits for benzene, ethylbenzene, and 2-propanol were 0.2 ppm, 0.1 ppm, and 3.0 ppm by volume, respectively, with a linear dynamic range greater than three orders of magnitude. These results indicate that the membrane inlet/time-of-flight mass spectrometry technique will be useful for a wide range of applications, particularly for in situ environmental monitoring.

• 한국식품영양학회지
• /
• 제17권4호
• /
• pp.412-419
• /
• 2004

쇠고기 엑기스 분말로부터 방사선 조사 휘발성 화합물의 검출에 의한 새로운 검지방법의 개발을 위한 기초 자료를 마련하고자 S-PD 법, S-CD 법, P&T 법 및 LLCE 법 등 4종의 방법을 대상으로 휘발성 화합물의 추출을 위한 최적의 방법을 선정하고자 하였다. 그 결과 쇠고기 엑기스 분말로부터 탄화수소류, 알데히드류, 케톤류, 알콜류, 함황화합물류, 함질소화합물류, 방향족화합물류, 테르펜류, 푸란류 및 기타 화합물류로 구성된 106종의 휘발성 화합물이 검출되었으며, 이 중 S-PD법에 의해 62종의 화합물이 검출됨으로써 가장 많은 화합물을 나타내었고, 다음으로 P&T 법(43종), LLCE 법(38종) 및 S-CD 법(30종) 순이었다. S-PD 법은 RI 1200 이상의 휘발성이 약하며 분자량이 높은 화합물에 대한 검출능이 높았고, P&T 법은 RI 1200 이하의 화합물의 검출능이 높은 경향을 나타냄으로서, 위 두 방법은 상호보완적인 경향을 나타내었다. 한편 S-CD법에 의해 검출된 화합물은 3종을 제외하고 S-PD 법에 의해서도 검출 가능하였으며, LLCE 법의 경우는 5종의 화합물을 제외하고 S-PD 법과 P&T법을 병용할 경우 모두 검출 가능한 화합물로 구성되어 있었다. 따라서 비극성 fiber(PDMS/DVB)를 사용한 SPME 법과 P&T 법을 병용하는 방법이 쇠고기 엑기스 분말의 휘발성 화합물을 추출하기 위한 최적의 방법으로 선정되었다.

• Archives of Pharmacal Research
• /
• 제28권12호
• /
• pp.1365-1375
• /
• 2005

The antiestrogenic effects of marijuana smoke condensate (MSC) and three major cannabinoids, i.e., $\bigtriangleup^{9}$-tetrahydrocannabinol (THC), cannabidiol (CBD), and cannabinol (CBN), were evaluated using in vitro bioassays, viz., the human breast cancer cell proliferation assay, the recombinant human estrogen receptor (ER) competitive binding assay, and the reporter gene assay. The inhibitory effects on estrogen were also examined using the ethoxyresorufin-O­deethylase (EROD) assay, the aromatase assay, and the 17$\beta$-estradiol ($E_{2}$) metabolism assay. The results showed that MSC induced the antiestrogenic effect via the ER-mediated pathway, while THC, CBD, and CBN did not have any antiestrogenic activity. This suggests that the combined effects of the marijuana smoke components are responsible for the antiestrogenicity of marijuana use. In addition, MSC induced the CYP1A activity and the $E_{2}$ metabolism, but inhibited the aromatase activity, suggesting that the antiestrogenic activity of MSC is also related to the indirect ER-dependent pathway, as a result of the depletion of the in situ $E_{2}$ level available to bind to the ER. In conclusion, pyrogenic products including polycyclic aromatic hydrocarbons (PAHs) in the non-polar fraction, which is the most biologically active fraction among the seven fractions of MSC, might be responsible for the antiestrogenic effect.

• 미생물학회지
• /
• 제53권1호
• /
• pp.64-66
• /
• 2017

Caballeronia sordidicola strain PAMC 26592 was isolated from Umbilicaria sp., a lichen material collected from Svalbard Archipelago in the Arctic Ocean. We report the draft genome sequence of the strain PAMC 26592, a metabolic generalist. As we have observed in previous genomic studies in the genus Caballeronia draft genomic sequences of PAMC 26592 had an assortment of genes of ecological importance and of bio-technical potentials, which include diverse metabolic genes for carbohydrates, aromatic compounds, amino acids, and vitamins, and genes for nitrogen / sulfur metabolisms, stress responses, membrane transporters, antibiotic resistance, and heavy metal resistance.

• Bulletin of the Korean Chemical Society
• /
• 제18권3호
• /
• pp.328-333
• /
• 1997

Dicyanovinyl-containing bis-hydroxy monomers, p-bis[1-(4-hydroxypiperidinyl)]-2,2-dicyanovinyl]benzene (2), p-bis[1-[1-(2-hydroxyethyl)piperazinyl]-2,2-dicyanovinyl]benzene (3), p-bis[1-(4-hydroxyphenylamino)-2,2-dicyanovinyl]benzene (4) and p-bis[1-[N-methyl-(N-hydroxyethyl)amino]]-2,2-dicyanovinyl]benzene (5) were prepared from p-bis(1-chloro-2,2-dicyanovinyl)benzene (1) and the corresponding amino alcohol. The poly(enaminonitriles-ester)s with a variety of chemical structures in the main chain were prepared from them. The chemical structure of polymers was confirmed through the syntheses of their corresponding model compounds. The polymers are easily soluble in polar aprotic solvents such as DMF, DMSO and NMP. Brittle and hard films can be cast from DMF solutions of polymers. Most polymers showed a large exotherm in DSC analyses and undergo a curing reaction around 350 ℃ to form insoluble materials. The polymers consisting of rigid aromatic moieties show 80-88% residual weight at 500 ℃ under nitrogen.

• Journal of Astronomy and Space Sciences
• /
• 제15권1호
• /
• pp.163-174
• /
• 1998

To study the origin of organic matter in meteorite, terrestrial rocks which contain or-ganic compounds similar to the ones found in carbonaceous chondrites are studied and compared with Muchison meteorite. Hydrocarbon molecules were extracted by benzene and methanol from bituminous coal and oil shale and the extracts were partitioned into aliphatic, aromatic, and polar fractions by silica gel column chromatography. Carbon isotopic ratios in each fractions were analysed by GC-C-IRMS. Molec-ular compound identifications were carried by GC-MS Engine. Bituminous coal and oil shale show the organic compound composition similar to that of meteorite. Oil shale has a wide range of ${\delta}^{13}C,-20.1%_0~-54.4%_0$ compared to bituminous coal, $-25.2%_0~34.3%_0$. Delta values of several molecular compounds in two terrestrial samples are different. They show several distinct distributions in isotopic ratios compared to those of meteorite; Murchison meteorite has a range of ${\delta}^13C\;from\;-13%_0\;to\;+30%_0$. These results provide interpretation for the source and the formation condition of each rock, in particular alteration and migration processes of organic matter. Especially, they show an important clue whether some hydrocarbon molecules observed in meteorite are indigenous or not.

• 한국지하수토양환경학회지:지하수토양환경
• /
• 제17권5호
• /
• pp.20-30
• /
• 2012

In case of analyzing PAHs (EPA 16 compounds) in oil-contaminated soils, the lump of peaks may occur because of the aliphatic and polar compounds in oil. This phenomenon is due to the lower accuracy of the analysis. To solve this problem, evaluation of application of silicagel-alumina multi-layer fraction was performed using standard substances and oil-contaminated soils. As a result of application of silicagel-alumina multi-layer fraction cleanup method using standard substances, recovery rates of surrogate standards (5 compounds including Naphthalene-d8) were 83~100% and those of target standards were 75~129%. These were to meet the target values (60~130%) in this study. When used 4% water-silicagel column analyze PAHs in oil-contaminated soils, Some problems were generated for quantitative analysis of PAHs; concentration of PAHs was underestimated due to an upward baseline of internal standard (recovery rate: less than 60%) and overestimated by the lump of peaks which were not purified (the biggest recovery rate: more than 400%). On the other hand, in case of silicagel-alumina multi-layer fraction cleanup method, recovery rate of surrogate standards were 61~101.6%. Therefore this cleanup method was considered a valid method to improve accuracy of analysis of PAHs in oil-contaminated soils.

• 한국환경과학회지
• /
• 제16권3호
• /
• pp.247-253
• /
• 2007

Polycyclic aromatic hydrocarbons (PAHs) are a major concern because of their potential mutagenic and carcinogenic risks to human beings. One of these harmful, yet commonly observed PAHs is pyrene. Pyrene is one of the 16 PAHs listed by the United States Environmental Protection Agency as priority pollutants. The purposes of this research are to develop a method of pretreatment for PAH contaminants prior to a typical biological treatment and to demonstrate the biodegradablity of these compounds. Since pyrene is non-polar, hexane was chosen as a solvent to effectively dissolve pyrene. Pyrene solutions were treated with ozone, as it has hish oxidation capacity and electrophilic character. The intermediates and byproducts of pyrene were dissolved in alkaline water at pH 11.4 and neutralized to test for $BOD_5$, COD, and toxicity. These solutions were further ozonated and assessed of biodegradability. The first-order rate constant to was found to be between $0.121day^{-1}$ and $0.081 day^{-1}$, depending on the duration of reozonation. The $BOD_5/COD$ ratio was found to 0.66. The toxicity test showed that after 10 min of reozonation time, the byproducts and intermediates of pyrene were within the lion-toxic range of ${\pm}10%$ inhibition for E-Coli bacteria.

• Korean Chemical Engineering Research
• /
• 제44권6호
• /
• pp.669-675
• /
• 2006

본 연구에서는 휘발성 유기화합물 중 산업공정에서 사용빈도가 가장 높은 방향족류의 toluene, 케톤류의 MEK, 알코올류의 IPA에 의한 삼성분계 휘발성 유기화합물의 탄소계 흡착제에 대한 흡착특성 실험을 수행하였다. 입상 활성탄, 활성탄소섬유를 이용한 단일흡착제와 입상 활성탄과 활성탄소섬유를 동시에 적용한 조합흡착제를 사용하여 흡착성능과 흡착량을 비교 분석하였다. 실험용 흡착장치를 사용하여 단일성분 및 삼성분계 휘발성 유기화합물에 대한 흡착파과 실험을 수행하였으며, 각 경우에 대해 흡착량과 흡착성능을 비교하였다. 입상 활성탄은 toluene의 단일흡착 시 높은 흡착성능을 보였으나, IPA, MEK의 단일성분과 삼성분계 흡착실험에서는 상대적으로 낮은 성능을 보였다. 활성탄소섬유와 조합흡착제는 단일성분 흡착결과에서 모두 우수한 흡착성능을 보였으나, 삼성분계 흡착의 경우에는 흡착제의 경제성과 흡착효율을 고려하였을 때 입상 활성탄과 활성탄소섬유를 동시에 적용한 조합흡착제가 흡착제로서 가장 적합함을 확인할 수 있었다.

• 한국도로학회논문집
• /
• 제3권1호
• /
• pp.177-184
• /
• 2001

본 연구는 노후된 폐아스콘으로부터 폐아스팔트를 추출하여 ASTM방법을 이용해서 폐아스팔트의 화학적 조성을 성분별로 분리하고, 이들을 신제아스팔트의 구성성분과 비교하여 노후시 변화하는 성분들을 파악하였다. 이러한 분석결과를 토대로 폐아스팔트의 성상복원을 위한 재생첨가제를 제조하여 재생첨가제를 10%, 20% 첨가했을 때 폐아스팔트의 복원정도를 침입도$(25^{\circ}C)$, 신도, 연화점, 점도의 네 가지 시험을 수행하여 폐아스팔트의 물성 변화 특성을 고찰하였다. 연구결과에 의하면 아스팔트의 노화시 아스팔텐의 함량이 하고, 방향족성분의 함량이 감소함을 알 수 있었고, 증가한 아스팔텐의 함량을 줄여주기 위해 아스팔트의 방향족 성분자 화학적으로 비슷한 아로마틱기유를 사용하여 재생첨가제를 제조했다. 그리고 제조된 재생첨가제를 노화가 진행된 폐아스팔트에 무게 비로 20% 첨가했을 때, 신제아스팔트 (AP-3)와 유사한 정도로 성상이 복원됨을 확인할 수 있었다.