• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2000년도 추계 학술대회
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• pp.165-167
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• 2000

• Bulletin of the Korean Chemical Society
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• 제24권9호
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• pp.1379-1380
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• 2003

• 분석과학
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• 제27권2호
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• pp.100-107
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• 2014

플라스틱은 뛰어난 조형성 및 대량생산의 장점에 의하여 점차 현대 미술에 전반적으로 쓰이게 되었다. 국내에서도 플라스틱 작품의 가치가 증대되고 있지만 산업용, 공업용 플라스틱에 대한 연구에 국한되어있다. 본 연구에서는 미술품으로서 제작에 사용되는 플라스틱 5종(PVC, PE, PP, PS, PU)의 극미량 시료를 이용하여 동정을 실시하였다. SPME를 이용한 VOCs 분석 결과, PVC는 방향족, 알칸류 화합물이 검출되었고 PE와 PP는 알칸류 화합물이 검출되었다. PS는 방향족 화합물이 확인되었고, PU는 폴리에스테르 기반의 PU에서 나타나는 diethylene glycol 등이 검출되었다. Pyrolysis 분석 결과, PVC에서 지방족 알켄류 화합물과 가소제(DEHP)가 확인되었고 PE 역시 지방족 알켄류 화합물과 가소제(DIBP)가 검출되었다. PP는 1-hexene 등이 검출되었으며 PS는 방향족 화합물이 확인되었고 PU는 폴리우레탄의 주요 재료인 MDI가 분석되었다. 이처럼 SPME와 pyrolysis 분석법으로 극미량의 시료를 이용하여 플라스틱 종류마다 각기 다른 특징적인 화합물이 검출됨으로써 동정 기술로써의 가능성을 확인하였다.

• Plant Biotechnology Reports
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• 제5권2호
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• pp.127-134
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• 2011

The biotransformation potential of cell suspension cultures generated from Withania somnifera leaf was investigated, using withanolides, i.e. withanolide A, withaferin A, and withanone as precursor substrates. Interestingly, the cell suspension cultures showed inter-conversion of withanolides, as well converted to some unknown compounds, released to the culture media. The bio-catalyzed withanolide was detected and quantified by TLC and HPLC, respectively. There is noticeable conversion of withanolide A to withanone, and vice versa though at a lower level. The type of reaction of this biotransformation appears to be substitution of 20-OH group to 17-OH in withanolide A. In this paper, we present for the first time the possibility of biotransformation by inter-conversion of withanolides of pharmacological importance through cell suspension culture of W. somnifera. The possible role of putative cytochrome $P_{450}$ hydroxylases is implicated in the conversion.

• 한국환경과학회지
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• 제15권7호
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• pp.643-651
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• 2006

This study investigated the distributive property of micropollutants in sediment around Gwang-yang bay using simultaneous analytical method of 310 chemicals. In the results, the major micropollutants detected were CH type chemicals such as aliphatic, polycyclic compounds, benzenes, and CHN(O) type chemicals aromatic amines, and pesticides. Insecticides of pesticide type were frequently detected at all sampling site. The total concentration of micropollutants were higher in summer than in winter and measured within the range of $ND{\sim}36.50{\mu}g/L$. Also, because of effect of seomjin river, GY6 of all sampling site detected by the highest concentration, GY10 and 11 located in Gwang-yang outside bay were not detected the micropollutants. From the result of this study, we should estimated that the industrial complex located in Gwang-yang inside bay and an inflow of fresh water through the Seomjin river are major pollution sources of Gwang-yang bay.

• 대한화학회지
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• 제39권10호
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• pp.812-817
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• 1995

방향족 니트로 화합물을 선택적으로 환원시켜 치환체가 있는 아닐린을 생성하는 것은 산업적 측면에서 볼때 의미있는 반응이다. 본 연구에서는 Bakers' Yeast-NaOH의 환원작용에 의하여 m-Bromonitrobenzene 의 니트로기가 선택적으로 빠르게 환원되어 치환체가 있는 아닐린 화합물이 형성됨을 확인하였고 특히 Nitrosobenzene이 수산화 나트륨이 없는 조건에서 Bakers' Yeast만의 작용에 의해 환원되어 아닐린을 생성함을 확인하였다. 또한 Nitrosobenzene의 Bakers' Yeast 환원에 미치는 저해제들의 효과 및 온도, pH의 영향 등을 조사하였다.

• 대한방사성의약품학회지
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• 제4권1호
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• pp.16-21
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• 2018

Organoboron compounds and their derivatives are synthetically versatile building blocks because they are readily available, stable, and highly useful for potential organic transformations. Arylboronic esters are of particular interest due to their well-established synthetic methods: transition metal catalyzed borylations of aryl halides. However, the use of aryl halides as an electrophile has one serious disadvantage: formation of toxic halogenated byproducts. A promising alternative substrate to aryl halides would be phenol derivatives such as aryl ethers, esters, carbamates and sulfonates. The phenol derivatives involve several advantages: their abundance, relatively low toxicity and versatile synthetic application. However, utilization of the aryl methyl ether, which is one of the simplest phenol derivatives, remains as a challenge, as C-OMe bond activation requires high activation energy and methoxides are not good leaving groups. Nevertheless, there have been a significant recent progress on ipso-borylation of aryl methyl ether including Martin's nickel catalysis. Here, we review the current advance on the borylation of carbon-oxygen bonds of unactivated C-OMe bond in aromatic compounds.

• 대한화학회지
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• 제22권5호
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• pp.326-333
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• 1978

Tetrazonium 염을 거쳐서 m-phenylenedihydrazine (MPDH)을 합성할 수 있었다. 즉, m-phenylenediamine을 진한 염산의 매질 속에서 $-10∼-5^{\circ}C$로 유지하고아질산나트륨으로 테트라 아조화한 다음, 이때 생긴 tetrazonium 염을 염화주석(II)으로 환원시켜 MPDH를 염산염의 꼴로 얻어 알코올에서 재결정 할 수 있었다. MPDH의 유리염기는 불안정하기 때문에 공기 중에서는 안정한 상태로 얻기 어려우며, 그 염산염은 명확한 녹는 점을 가지지 않고 $185^{\circ}C$에서 분해하였다. MPDH도 방향족 monohydrazine의 경우 처럼 mono 또는 dicarbnyl 화합물과 쉽게 축합반응을 일으켜서 dihydrazone 또는 고리모양 화합물을 생성하였다. MPDH와 carbonyl 화합물과의 반응에서 얻은 여러가지 화합물의 구조를 결정하였다.

• 한국환경과학회지
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• 제4권5호
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• pp.61-61
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• 1995

Volatile organic compounds(VOCs) are of concern for their potential chronic toxicity, their suspected role in the formation of smog, and their suspected role in destruction of stratospheric ozone. Present study evaluated the exposures to selected VOCs in three microenvironments: 2 chlorinated and 5 aromatic VOCs in the indoor and outdoor air, and 5 aromatic VOCs in the breathing zone air of gas-service station attendants. With permissible Quality Assurance and Quality Control performances VOC concentrations were measured 1) to be higher in indoor air than in outdoor air, 2) to be higher in two Taegu residential areas than in a residential area of Hayang, and 3) to be higher in the nighttime than in the daytime. Among five aromatics, Benzene and Toluene were two most highly measured VOCs in breathing zone air of service station attendants. Based on the sum of VOC concentrations, the VOC exposure during refueling was estimated to be about 10% of indoor and outdoor exposures. For Benzene only, the exposure during refueling was estimated to cause about 52% of indoor and outdoor exposure. The time used to calculate the exposures was 2 minutes for refueling and 24 hours for indoor and outdoor exposures.

• 한국환경과학회지
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• 제4권5호
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• pp.447-459
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• 1995

Volatile organic compounds(VOCs) are of concern for their potential chronic toxicity, their suspected role in the formation of smog, and their suspected role in destruction of stratospheric ozone. Present study evaluated the exposures to selected VOCs in three microenvironments: 2 chlorinated and 5 aromatic VOCs in the indoor and outdoor air, and 5 aromatic VOCs in the breathing zone air of gas-service station attendants. With permissible Quality Assurance and Quality Control performances VOC concentrations were measured 1) to be higher in indoor air than in outdoor air, 2) to be higher in two Taegu residential areas than in a residential area of Hayang, and 3) to be higher in the nighttime than in the daytime. Among five aromatics, Benzene and Toluene were two most highly measured VOCs in breathing zone air of service station attendants. Based on the sum of VOC concentrations, the VOC exposure during refueling was estimated to be about 10% of indoor and outdoor exposures. For Benzene only, the exposure during refueling was estimated to cause about 52% of indoor and outdoor exposure. The time used to calculate the exposures was 2 minutes for refueling and 24 hours for indoor and outdoor exposures.