通过"实验三号"开放航次在南海北部采集了32个大气样品,用气相色谱/质谱联用仪分析了样品中的多溴联苯醚(PBDEs)同系物,并对其含量、组成特征、空间分布及主要来源进行了研究.结果表明,南海北部大气中7种PBDEs总浓度为0.07~35.9 pg.m-3,四溴(BDE-47)和五溴(BDE-99和-100)化合物为主要组成,分别约占PBDEs总量的51.5%和36.9%,显示工业五溴联苯醚的使用是其主要来源;中国东南沿海和菲律宾附近PBDEs浓度较高,南海靠近越南中部海域大气PBDEs含量较低.后推气流轨迹分析指出:我国东南沿海,特别是珠江三角洲,以及我国台湾和菲律宾等地区陆源污染物的外溢是引起南海北部地区PBDEs浓度较高的主要原因.
A total of 32 air samples collected during a Shiyan Ⅲ voyage over the northern South China Sea(SCS) were analyzed for polybrominated diphenyl ethers(PBDEs) by gas chromatography/mass spectrometry.The concentrations of ∑7PBDEs ranged from 0.07 to 35.9 pg·m-3.The ∑7PBDEs were dominated by tetra-(BDE-47) and penta-(BDE-99 and-100) components,which accounted for 51.5% and 36.9%,respectively.This result indicated that the widely used commercial penta-BDE product was the original source.The higher concentrations of PBDEs were monitored close to the coastline of the South China and Philippine,while the lower concentrations were found over the SCS adjacent to central coast of Vietnam.Back trajectory analysis showed that the high PBDE concentrations observed in air over the northern SCS may be related to the continental pollutant outflows from the southeast coast of China,especially the Pearl River Delta,Taiwan and Philippine,by prevailing northeast wind transport.