Abstract: The contents of 6 PCBs in river water at Toudaoguai section of the Yellow River were analyzed by GC-ECD. The total contents of PCBs ranged from 1.61 ng·L^-1 to 5.12 ng·L^-1 with an average value of 3.38 ng·L^-1. The main compositions were the low-chloride compounds, and the detectable ratio of PCB29 and PCB98 was 100%. The highest and lowest contents of PCBs occurred in August and October respectively. Holistically, the contents of PCBs were high in spring and summer but low in autumn and winter. Moreover, a primary study on the influences of surrounding factors, such as temperature, pH value, ion intensity and organic matter content on desorption was carried out. The results showed that the contents of PCBs were positively correlated with temperature, pH value and ion intensity, and they were obviously affected by organic matter content in suspended sediment. It was found that there was a positive correlation among the PCBs congeners (PCB5, PCB29 and PCB47), which indicated that the sources of pollutants were the same and stable. Compared with the EPA and the national surface water environment quality criteria (GB3838-2002), the contents of PCBs at Toudaoguai section of the Yellow River were lower than the criteria.

Key words: water body, polychlorinated biphenyls (PCBs), temporal distribution, Toudaoguai section, the Yellow River