Quantification of PCBs using GC-ECD and Cost-effective Estimation of Dioxin-like PCBs in the Sediment of Urban Streams in Seoul, Korea

Abstract

In this study, the concentration of polychlorinated biphenyls (PCBs) remaining in the sediment of Han River and its 4 tributaries was investigated in a cost-effective method using gas chromatography-electron capture detector (GC-ECD). The concentration of total PCBs was calculated by summing up the individual Aroclor concentration quantified using specific congeners of each Aroclor. By quantifying individual Aroclors, the concentration of dioxin-like PCBs (dl-PCBs) and toxicity equivalency quotient (TEQ) for sediment samples could be estimated using simple formulae derived from the information of dl-PCBs content in individual Aroclors. Although it was not possible to compare the estimated concentration of dl-PCBs with the concentration analyzed by high-resolution mass spectrometry (HRMS) for the same sample, acceptable results were obtained through comparison with the concentration of sediment samples at adjacent points in previous studies. As a result, PCB concentration remaining in the sediments in the urban stream was relatively high in the sediments near the industrial area. In the case of the two tributaries adjacent to the industrial area, the concentrations of PCBs in most sediment samples exceeded the effective range low (ERL) value and at certain points exceeded the effective range median (ERM) value. In addition, most high concentrations of PCBs were commonly detected at the junction of the river and its tributary where the flow rate slowed noticeably. Therefore, it is necessary to consider the junction of rivers as an important sampling point when investigating PCBs in sediments. Key Words: PCBs, Aroclor, GC-ECD, dl-PCBs, Sediment, SQGs