• Analytical Science and Technology
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• v.24 no.6
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• pp.484-492
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• 2011

Bioaccumulation status and distribution characteristics of PCDDs, PCDFs and DL-PCBs in cruian carp collected from the four representative sites of major river systems in Korea were investigated. The recovery rates of PCDDs and PCDFs ranged from 50.6% to 88.3%, and those of DL-PCBs ranged from 52.3% to 93.2%. The mean, median and concentration range of ${\sum}$dioxins, which represents the total concentratons of PCDDs, PCDFs and DL-PCBs accumulated in the muscle of crucian carp, were 0.39, 0.14 and 0.047-1.0 pg TEQ/g wet wt., respectively. DL-PCBs were detected above the detection limit from all the samples, whereas PCDDs and PCDFs were detected from limited crucian samples. The relative contribution of DL-PCBs to ${\sum}$dioxins was remarkably larger than those for PCDDs and PCDFs. The percent contribution was 83.6% for DL-PCBs, and followed by 12.7% and 3.7% for PCDFs and PCDDs, respectively.

• Journal of Environmental Science International
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• v.21 no.4
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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.

• Analytical Science and Technology
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• v.13 no.6
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• pp.789-801
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• 2000

This analysis was conducted for PCDDs/PCDFs in sediment by isotope dilution HRGC/HRMS method. From the result, the mean recovery of surrogate standard was in the range of 70.1-80.8%. Among the distribution of 2, 3, 7, 8-substituted isomers, the concentration of OCDD represented almost 40.6-78.5% of total concentration and that of OCDF showed 6.6-14.7% and 1, 2, 3, 4, 6, 7, 8-HpCDD showed 5.1-7.7%. The portion of PCDDs represented 62.4-86.9% of total PCDDs/PCDFs. In the TEQ concentration 1, 2, 3, 4, 7, 8-PeCDF concentration represented 22.7-35.6 % of total TEQ concentration.

• Analytical Science and Technology
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• v.20 no.1
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• pp.10-16
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• 2007

This research was designed to investigate the formations of hazardous air pollutants in the MSWs pyrolysis-gasification-melting process. In this survey, PCDDs/PCDFs (polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofuran) were investigated in the two facilities (A and B facilities). In A facility, the PCDDs/DFs concentrations were 0.88, 2.29, 0.16 ng I-TEQ/$m^3$ respectively on the secondary incinerator, boiler and stack. In B facility, the PCDDs/PCDFs concentrations were 0.22, 0.05 ng I-TEQ/$m^3$ respectively on the pyrolysis-gasification-melting furnace and stack. The concentrations of PCDDs/PCDFs increased due to resynthesis during cooling process in the both facilities. High concentrations of PCDDs/PCDFs isomers were founded as 2, 3, 4, 7, 8-PeCDF, 2, 3, 4, 6, 7, 8-HxCDF and 1, 2, 3, 6, 7, 8-HxCDF orderly in A facility, and 2, 3, 4, 7, 8-PeCDF, 1, 2, 3, 7, 8-PeCDD and 2, 3, 4, 6, 7, 8-HxCDF orderly in B facility.

• Journal of Environmental Science International
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• v.14 no.7
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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.

• Journal of Environmental Health Sciences
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• v.33 no.1 s.94
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• pp.11-15
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• 2007

This study was performed to evaluate the congeners of polychlorinated dibenzo-p-dioxins(PCDDS) and polychlorinated dibenzofurans(PCDFs) in Korean foods among children in Korea, in comparison with the findings in their mothers. The PCDDs and PCDFs intakes of 24-h diet duplicates were estimated from the previous Korean reports. In Korean children and their mothers of this study, major sources of lipid intake were plant-based foods(62% for children, 66% for their mothers). The women took 34% of lipid from animal sources, among which meats were leading sources of animal lipids(30%). Fish and shellfish were accounted for 4% in total lipid intake. Daily intake of PCDDs and PCDFs in the children md their mothers were 0.002-3.188 and 0.002-2.717 pg WHO-TEQ/day in animal sources and ND-0.283 and ND-0.296 pg WHO-TEQ/day in plant sources, respectively. PCDDs/PCDFs intake from animal origin was the major exposure source for both children and their mothers in Korea. Among the 17 PCDD/Fs congeners, 2,3,4,7,8-pentachlorodibenzofuran was assumed to be the effective exposure marker for diet intake.

• Bulletin of the Korean Chemical Society
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• v.20 no.6
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• pp.689-695
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• 1999

Supercritical fluid extraction (SFE), ultrasonic extraction (USE), and accelerated solvent extraction (ASE) were compared with the well known Soxhlet extraction for the extraction of polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins(PCDDs) from the XAD-2 resin which was used to adsorb PCDDs in the atmosphere. XAD-2 resin spiked with five PCDDs was chosen as a sample. The optimum conditions for the extraction of PCDDs by SFE were turned out to be the use of CO2 modified with 10% toluene at 100 ℃ and 350 atm, with 5 min static extraction followed by 20 min dynamic extraction. SFE gave a good extraction rate with good reproducibility for PCDDs ranging from 68 to 98%. The ultrasonic extraction of PCDDs from XAD-2 was investigated and compared with other extractions. A probe type method was compared with a bath type. Two extraction solvents, toluene and acetone were compared with their mixture. The use of their mixture in probe type, with 9 minutes of extraction time, was found to be the optimum condition. The average recovery of the five PCDDs for USE was 82-93%. Accelerated solvent extraction (ASE) with a liquid solvent, a new technique for sample preparation, was performed under elevated temperatures and pressures. The effect of tem-perature on the efficiency of ASE was investigated. The extraction time for a 10 g sample was less than 15 min, when the organic solvent was n-hexaneacetone mixture (1 : 1, v/v). Using ASE, the average recoveries of five PCDDs ranged from 90 to 103%. SFE, USE, and ASE were faster and less laborious than Soxhlet extraction. The former three methods required less solvent than Soxhlet extraction. SFE required no concentration of the solvent extracts. SFE and ASE failed to perform simultaneous parallel extractions because of instrumental limitations.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.2
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• pp.125-131
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• 2009

Reductive dechlorination of polychlorinated dibenzo-p-dioxins (PCDDs) and its toxicity change were predicted by the linear free energy relationship (LFER) model to assess the zero-valent iron (ZVI) and anaerobic dechlorinating bacteria (ADB) as electron donors in PCDDs dechlorination. Reductive dechlorination of PCDDs involves 256 reactions linking 76 congeners with highly variable toxicities, so is challenging to assess the overall effect of this process on the environmental impact of PCDD contamination. The Gibbs free energies of PCDDs in aqueous solution were updated to density functional theory (DFT) calculation level from thermodynamic results of literatures. All of dechlorination kinetics of PCDDs was evaluated from the linear correlation between the experimental dechlorination kinetics of PCDDs and the calculated thermodynamics of PCDDs. As a result, it was predicted that over 100 years would be taken for the complete dechlorination of octachlorinated dibenzo-p-dioxin (OCDD) to non-chlorinated compound (dibenzo-p-dioxin, DD), and the toxic equivalent quantity (TEQ) of PCDDs could increase to 10 times larger from initial TEQ with the dechlorination process. The results imply that the single reductive dechlorination using ZVI or ADB is not suitable for the treatment strategy of PCDDs contaminated soil, sediment and fly ash. This LFER approach is applicable for the prediction of dechlorination process for organohalogen compounds and for the assessment of electron donating system for treatment strategies.

• Analytical Science and Technology
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• v.18 no.1
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• pp.13-22
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• 2005

The elution patterns of seventeen 2,3,7,8-substituted PCDDs/Fs and 12 dioxin-like PCBs were studied by both manual open columns and automatic parallel LC columns in cleanup procedure. PCDDs/Fs and non-ortho-PCBs from other mono-ortho-PCBs were separated on automatic LC column, whereas they were not separated on an open manual column. The elution study on two cleanup methods was carried out using the PAR solution of unlabeled congeners and checked the recovery of each congener. Total recoveries of cleanup fractionation were ranged between 61.9 ~ 96.0% for PCDDs/Fs and 70.4 ~ 79.0% for PCBs by manual open columns and 71.8 ~ 104.5% for PCDDs/Fs and 61.3-120.3% for PCBs by automatic parallel LC columns, respectively. Unfortunately, #169-HxCB and 1,2,3,7,8-PeCDD were not separated on DB-5MS capillary column. The ions of 1,2,3,7,8-PeCDD were selected at M/M+2 instead of M+2/M+4 suggested by EPA method 1613. It is possible to discriminate 1,2,3,7,8-PeCDD and PCB #169 in HRGC/HRMS analysis.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.7
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• pp.1345-1355
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• 2000

The main route of exposure of the human population to polychlorinated dibenzop-dioxins(PCDDs) and polychlorinated dibenzofurans(PCDFs) is through the diet. However in Korea, there are few studies on PCDDs/PCDFs levels in environmental samples and foods. The purpose of this study is to analyze concentration of PCDDs/PCDFs in Korean retail foods and to estimate dietary daily intake of them. 9 samples from animal food and 10 samples from plant food were analysed for PCDDs/PCDFs. Concentrations of PCDDs/PCDFs ranged from 0.02(milk) to 5.39(anchovy)pg/g. TEQ levels appeared in order of fish/shellfish, meat, vegetable, cereal, fruit and milk, and these values ranged from 0.0008 to 0.3153pgTEQ/g. The daily intake of PCDDs/PCDFs via food was calculated to be about 37.7pgTEQ/day and these values are equivalent to 0.75 pgTEQ/kg b.w./day, under consideration of 50kg for body weight. The daily intake of PCDDs/PCDFs via food was lower than that in other countries. From these results, it is important to note that fish/shellfish intake is one of the main sources of PCDDs/PCDFs exposure in Korea.