• 분석과학
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• 제8권4호
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• pp.821-827
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• 1995

Polychlorodibenzo-p-dioxins(PCDDs) have been prepared by microsacale pyrolysis of trichlorophenates. During the pyrolysis reaction, dechlorinated dibenzo-p-dioxins were also formed by the thermolysis of PCDDs. The dechlorination pathways of PCDDs were suggested in this reaction. The identification of these products was performed using capillary column gas chromatography-mass spectrometry.

• 대한환경공학회지
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• 제28권5호
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• pp.511-521
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• 2006

페놀류 전구물질로부터 형성된 polychlorinated dibenzo-p-dioxins(PCDDs)와 dibenzofurans(PCDFs)의 모든 동족체와 이성질체의 경향을 페놀과 19개의 염화페놀류의 분포를 이용하여 연구하였다. 실험은 $400^{\circ}C$(particle-mediated formation)와 $600{\sim}700^{\circ}C$(gas-phase formation)에서 각각 행하여 졌으며, 운반가스로 사용된 가스의 조성은 92%의 질소와 8%의 산소를 사용하였다. 염소기가 없는 dibenzo-p-dioxin(DD)와 dibenzofuran(DF)를 포함한 모든 종류의 PCDDs와 PCDFs의 동족체와 이성질체들이 20개의 페놀류를 혼합하여 사용한 본 실험으로부터 얻어졌다. 가스상 실험은 PCDFs가 많이 생성하였고, 입자상 실험에서는 PCDDs를 많이 생성 하였다. 가장 많이 생성된 동족체는 각각 DD와 DF였으며, 염소기의 숫자가 증가할수록, 동족체의 생성량은 감소하였다. 하지만 가스상과 입자상 실험에서 얻어진 PCDDs와 PCDFs의 동족체와 이성질체의 분포는 거의 항상 일정하였다. 고농도로 존재하는 페놀과 적은수의 염소기를 가지고 있는 염화 페놀류의 농도가 가스상과 입자상에서 발생하는 PCDDs와 PCDFs의 분포에 아주 중요한 역활을 하였다.

• 한국환경과학회지
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• 제21권4호
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• pp.451-459
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• 2012

PCDDs(Polychlorinated dibenzo-$p$-dioxins) and PCDFs(polychlorinated dibenzofurans) are measured in soil of Yeungju and Sangju on North Gyeongbuk to investigate the risk assessment of dioxins. Dioxins are analyzed by HRGC/HRMS(high resolution gas chromatography - high resolution mass spectrometer). 2,3,7,8-T4CDD and 1,2,3,7,8-Pe5CDD in soil on Yeungju and Sangju are not detected. Also, 2,3,7,8-T4CDF is not detected in soil on Yeungju and Sangju. PCDDs and PCDFs in Yeungju soil are 1.957 pg/g and 0.294 pg/g, respectively. Total of dioxins in Yeungju soil are 2.251 pg/g. PCDDs and PCDFs in Sangju soil are 1.220 pg/g and 0.420 pg/g, respectively. Total of dioxins in Sangju soil are 1.640 pg/g. PCDDs and PCDFs in Yeungju soil are 0.0049 pg WHO-TEQ/g and 0.0123 pg WHO-TEQ/g, respectively. Total of dioxins with PCDDs and PCDFs in Yeungju soil are 0.0172 pg WHO-TEQ/g. PCDDs and PCDFs in Sangju soil are 0.0065 pg WHO-TEQ/g and 0.0213 pg WHO-TEQ/g, respectively. Total of dioxins with PCDDs and PCDFs in Sangju soil are 0.0278 pg WHO-TEQ/g. Amount for pg/g concentration unit of PCDDs is higher than amount of PCDFs in soil. But, WHO-TEQ of PCDFs is higher than WHO-TEQ of PCDDs in soil.

• 한국환경과학회지
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• 제14권7호
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• pp.629-637
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• 2005

Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were investigated in soil and pine needle samples taken from 16 sites of industrial and residential areas in Changwon, Korea to assess their distribution levels and to suggest the influence of industrial activities, PCDDs/DFs levels in the soil samples ranged from 0.57 to 20.79 pg I-TEQ/g dry weight with a mean value of 4.20 pg I-TEQ/g dry weight. PCDDs/DFs levels in the pine needle samples ranged from 0.39 to 8.75 pg I-TEQ/g dry weight with a mean value of 4.09 pg I-TEQ/g dry weight. In both soil and pine needle samples, the PCDDs/DFs concentrations in the industrial area sites were higher than those in the residential area sites. Homologue profiles in pine needle samples showed different patterns compared with soil samples. Based on the results of principal component analysis (PCA), it was confirmed that pine needles reflected a direct influence from local potential sources of PCDDs/DFs, showing a much higher degree of reflection than in soils. Pine needles are very useful as an indicator for monitoring or estimating the contamination of PCDDs/DFs in other areas which have been impacted by point pollution sources.

• Fisheries and Aquatic Sciences
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• 제4권2호
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• pp.51-57
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• 2001

Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) were measured in sediment samples from 19 stations in the coastal areas of Korea from February to July 2000. PCDDs and PCDFs were detected in all sediment samples. The concentrations of these con­taminants ranged from 18.2 to 804.0 pg/g dry weight and I-TEQ concentrations varied from 0.1 to 5.5 pg/g dry weight. Examination of homologue groups showed that octachlorinated dibenzo-p-dioxin (OCDD) was predominant congener in Korean coast. This pattern was similar to homologue profiles of marine sediments in which the main source of PCDDs/DFs was derived from the atmospheric deposition of particulate matters generated from various industrial activities. Grain size and total organic carbon (TOC) distribution are one of the important factors governing PCDDs/DFs concentration in this study.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2003년도 추계학술대회
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• pp.172-173
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• 2003

There are growing concerns about human health effects of dioxin and dioxin like compounds such as polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs). Earlier studies recognized that 2.3.7.8-tetrachloro dibenzo-p-dioxin (TCDD) and structually related dioxin like compounds invoke a number of common toxic responses that are mediated through a high-affinity cytosolic receptor protein, the AhR.(omitted)

• Bulletin of the Korean Chemical Society
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• 제24권6호
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• pp.792-796
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• 2003

Polychlorinated dibenzo-p-dioxins (PCDDs) are extremely toxic and persistent environmental pollutants. Their chemical reactivities and other physicochemical/biological properties show a strong dependence on the chlorination pattern. With increasing the number of chlorines, dioxin congeners become more electronegative and gain higher electron affinities. The vertical electron affinities (VEA) are related with the LUMO energies of neutral molecules. LUMO energies of all PCDD congeners were calculated at the B3LYP/6-31G** level and those of some selected congeners at the level of B3LYP/6-311G**//B3LYP/6-31G** and B3LYP/cc-pvtz/ /B3LYP/6-31G**. The total energies of neutral and anionic species for dibenzo-p-dioxins (DD), 1469-TCDD, 2378-TCDD, and OCDD were calculated at the level of B3LYP/6-31G**, B3LYP/aug-cc-pvdz, and B3LYP/ aug-cc-pvtz//B3LYP/6-31G**. By using the four congeners with D2h symmetry as reference molecules, we could estimate VEA (B3LYP/aug-cc-pvdz) of 75 PCDD congeners based on the linear correlations between LUMO energy and VEA (B3LYP/6-31G**) and between VEA (B3LYP/6-31G**) and VEA (B3LYP/aug-ccpvtz// B3LYP/6-31G**). Results show that all PCDDs with the number of Cl ≥ 3 have positive electron affinities. The PCDD electron affinity values provided in this work can be a useful data set in understanding the congener-specific reactivities of dioxins in various environmental media.

• 한국물환경학회지
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• 제24권6호
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• pp.758-766
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• 2008

먹는물 처리 전후 다이옥신류의 동족체 패턴 및 제거율을 평가하기 위해서 42개의 일본 정수처리장에서 2년간 122개의 시료를 채취해 dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) 및 coplanar polychlorinated biphenyls (Co-PCBs)를 분석하였다. 다이옥신류의 평균 농도와 독성등가값 (toxic equivalent, TEQ)은 원수와 처리수에서 각각 60.24 pg/L (0.14 pg-WHO-TEQ/L), 4.15 pg/L (0.016 pg-WHO-TEQ/L)였다. 먹는물의 다이옥신류 기여 농도는 일일섭취량 (tolerable daily intake (TDI), 4 pg-TEQ/kg/day)의 0.016%이었다. 정수처리에 의한 다이옥신류의 평균 TEQ 제거율은 88% 이상이었다. 그러나 112개의 샘플에서 2, 3, 7, 8-TeCDF (tetrachlorodibenzofuran)의 농도는 17% 증가하였다. 따라서, 2, 3, 7, 8-TeCDF의 농도에 영향을 미치는 공정을 파악하기 위하여 고도정수처리 및 일반정수처리에서의 제거율을 조사하였다. 다이옥신 동족체(congener)인 TeCDF와 non-ortho-PCB는 고도처리 및 표준정수처리에서 염소소독처리 후 TEQ 농도가 증가함을 보여, 먹는물 중 2, 3, 7, 8-TeCDF 농도는 염소소독처리에 의해 상승한 것으로 밝혀졌다.

• 대한수의학회지
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• 제48권1호
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• pp.39-48
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• 2008

Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) are ubiquitous and can contaminate the food chain. A study monitoring PCDD/Fs in imported meat was conducted at the National Veterinary Research and Quarantine Service (NVRQS, Republic of Korea) in order to maintain food safety from the bioaccumulative PCDD/Fs. Seventeen PCDD/Fs with toxic equivalency factors (TEFs) established by World Health Organization (WHO, 1998) were analyzed in imported beef, pork, and chicken by high resolution gas chromatography/mass spectrometry (HR-GC/MS). Results of the monitoring for the last 5 years are presented. The levels of PCDD/Fs were similar to other studies except two unusually high concentrations in pork and beef. Excessive levels greater than the Korean provisional maximum residue limit of PCDD/Fs were found in a sample of pork imported from Chile and a sample of beef imported from U.S, and those products were rejected and returned. There was no obvious trend or differences with respect to time or origin of meat in this study.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2003년도 추계국제학술대회
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• pp.9-9
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• 2003

There are growing concerns about human health effects of dioxin and dioxin like compounds such as polychlorinated dibenzo-p-dioxins (PCDDS), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs), Earlier studies recognized that 2,3,7,8-tetrachloro dibenzo-p-dioxin (TCDD) and structually related dioxin like compounds invoke a number of common toxic responses that are mediated through a high-affinity cytosolic receptor protein, the AhR. Based on studies that Indicate th pivotal role of AhR in mediating most, if not all, of the dioxin toxicity, TCDD equivalency factor (TEF) approach was developed. This approach allowed the expression of toxic potential of a complex mixture as one integrated parameter, the toxic equivalency (TEQ) value.