Levels, distributions and isomer profiles of hexabromocyclododecanes in the riverine sediments of the Laizhou Bay area, North China
LIU Yi-kai;WANG Jing-zhi;TANG Jian-hui;YU Zhi-qiang;ZHANG Gan;Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research,Chinese Academy of Sciences, Shandong Provincial Key Laboratory of Coastal Zone Environmental Processes;University of Chinese Academy of Sciences;Guangzhou Institute of Geochemistry,Chinese Academy of Sciences;
Thirty-six surface sediment samples were collected from nearly ten rivers or distributaries in the Laizhou Bay area. Three diastereoisomers of hexabromocyclododecanes(HBCDs) were analyzed by high performance liquid chromatograph, coupled to a triple quadrupole mass spectrometer(HPLC-MS/MS). The concentrations of HBCDs ranged from 0.03 to 20.17 ng/g dw, with a mean vale of 2.14 ng/g dw. The study area is less contaminated by HBCDs in comparison with other riverine regions around the world. HBCD diastereoisomer profiles differed among the sediment samples, and γ-HBCD(52.3%–97.3%, mean 72.4%) was the dominant isomer(except one sample), whereas α-HBCD contributions were relatively high in sediments from the rural areas. Higher concentrations occurred mostly at industry areas, indicating the sources of HBCD was direct discharge from local factories; however, in the less industrial areas, including urban areas and rural areas, sources of HBCDs were from atmospheric transport and deposition. Moreover, relatively strong correlation between TOC and HBCD concentrations suggested that TOC is the control factor for HBCD distribution in the less industrial areas.