Gi Ho Jeong

Distribution characteristics of PCBs in the sediments of the lower Nakdong River, Korea.

The objective of this study is to investigate the distribution characteristics of polychlorinated biphenyl (PCB) congeners in sediments of the lower Nakdong River of Korea. The sediments were collected using a grab sampler in May 1999. PCBs were extracted in the Soxhlet extractor and cleaned by using adsorption chromatographic techniques and concentrated sulfuric acid. A HP6890 gas chromatograph equipped with an electron capture detector was used for quantification. The results of congener specific analysis showed that the total concentration is ranged over 1.1-141 ng/g dry weight. The levels of PCB congeners are significantly correlated with the total organic carbons (TOC) in the sediments. The major fractions of PCBs in these sediments are congeners containing 4, 5 or 6 chlorine atoms per biphenyl molecule.

Hexabromocyclododecanes in crucian carp and sediment from the major rivers in Korea.

The concentration of hexabromocyclododecanes (HBCDs) was measured in crucian carp muscles and eggs and in surrounding sediments collected from the 3 major rivers in Korea. HBCDs were detected in all carp and sediment samples, indicating widespread contamination of this area by HBCD flame retardants. The ∑HBCD (sum of α-, β-, and γ-HBCDs) concentrations ranged from 0.19 to 13 ng g(-1)dry wt in sediments, 1.7 to 7.2 ng g(-1)lipid wt in carp eggs, and 4.8 to 6.6 ng g(-1)lipid wt in the muscle of carp. The α-diastereomer predominated in the crucian carp and γ-diastereomer predominated in sediments, accounting for 76% and 77% to the ∑HBCD, respectively. The ∑HBCD concentrations in carp and sediment samples collected along the rivers were higher than those in samples collected from an isolated pond, suggesting that the rivers are likely contaminated by HBCDs from the upstream or the environment surrounding the rivers. The diastereomer ratios in carp were different from those in commercial mixtures due to the enrichment of α-diastereomer in carp. The origin of this transition, however, is yet not known, since various transformation processes can lead to a change from the diastereomer ratio in commercial mixtures to that observed in the environment.

Polychlorinated dibenzo-p-dioxins, dibenzofurans and biphenyls in crucian carp (Carassius auratus) from rivers in Korea during 2000–2004

Concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were analyzed in freshwater fish (crucian carp) taken from 16 locations in nine rivers and a wetland in Korea, during 2000-2004. Dioxin-like polychlorinated biphenyls (DL-PCBs) were also analyzed in the same samples but over shorter period (2002-2004). Concentrations on a wet weight basis for 3 years (2002-2004) ranged from below the detection limit (DL) to 0.36 pg TEQ g(-1) wet wt. for PCDDs, below the DL to 2.0 for PCDFs, and from 0.02 to 1.9 for DL-PCBs, with a mean of 0.07, 0.33 and 0.83 pg TEQ g(-1) wet wt., respectively. The proportions of PCDDs, PCDFs and DL-PCBs in the total dioxin TEQ for 2002-2004 were 7%, 26% and 67%, respectively. While the temporal trend showed a significant decrease in PCDDs/DFs concentrations over the 5-year study period, DL-PCBs did not show significant change in concentration over the 3-year period. The results suggest that DL-PCBs concentrations should be determined when total dioxin TEQ is analyzed in freshwater fish.

Distribution characteristics of perfluorinated compounds in major river water and sediment

We have developed analysis method of PFCs in river water and sediment, and determined seven species of PFCs such as PFBS, PFHxS, PFOS, PFHpA, PFOA, PFNA and PFDA. Water and sediment samples were collected from 21 and 13 different sites along the Nakdong, Seomjin and Nam River, respectively. The water samples were pretreated with HLB cartridge and sediment samples were concentrated after extracted by sonication, and the levels of PFCs were determined by LC-MS/MS. The coefficient of determination (R) values of calibration curves were higher than 0.99. The method detection limits ranged 0.09~0.63 ng/L in water and 0.013~0.020 ng/g in sediment. The recovery rates of PFCs was found to be 74~98% for water and 87~111% for sediment. PFOA was the major species in water samples and followed by PFHpA and PFOS. In sediment, PFOA, PFOS and PFDA showed similar levels. Both water and sediment samples collected from the Nakdong River showed the highest concentrations of PFCs among the three rivers. 요 약: 본 연구에서는 perfluorobutanesulfonate (PFBS), perfluorohexanesulfonate (PFHxS), perfluorooctanesulfonate (PFOS), perfluoroheptanoate (PFHpA), perfluorooctanoate (PFOA), perfluorononanoate (PFNA) 및 perfluorodecanoate (PFDA) 등 과불화화합물 7 종의 분석방법을 정립하고 우리나라 주요 하천 수 및 퇴적토에 대한 과불화합물의 축적 정도를 분석하고 그 특성을 살펴보았다. 낙동강, 섬진강, 남강을 따라 총 21 개 지점에서 물 시료를, 13 개 지점에서 퇴적토 시료를 채취하였다. 물 시료는 HLB 카트리 지를 이용하여 전처리하였고, 퇴적토 시료는 초음파 추출을 거친 후 농축하였으며 모두 LC-MS/MS로 분 석하였다. 검정곡선의 결정계수(R)는 0.99 이상, MDL은 물 시료에서 0.09~0.63 ng/L, 퇴적토 시료에서 0.013~0.020 ng/g을 얻었고, 회수율은 물 시료에서 74~98%, 퇴적토 시료에서 87~111%로 나타났다. 하천 수에서는 PFOA가 가장 높은 농도를 나타내었고 PFHpA, PFOS가 그 다음으로 높은 농도를 나타냈으며, 퇴적토에서는 PFOA, PFOS 및 PFDA가 비슷한 수준으로 검출되었다. 하천수와 퇴적토 모두 낙동강에서 채취한 시료에서 PFCs의 농도가 가장 높게 나타났다.

Analysis of 2,3,7,8-substituted PCDDs, PCDFs, and DL-PCBs in muscle of crucian carp (Carassius auratus and Carassius cuvieri) from major rivers and lakes

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 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 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.