珠江三角洲沉积物钻孔中多溴联苯醚的垂直变化规律研究

Vertical distributions of polybrominated diphenyl ethers of sediment core in the Pearl River Delta

采用GC/MS分析方法测定了珠江三角洲水体5个钻孔(分别采自东江东莞段、珠江广州段、北江中段、西江入海口和顺德段)80个样品中10种多溴联苯醚(PBDEs,BDE209和∑9BDEs)的含量,对其沉积规律进行研究和探讨.∑9BDEs含量范围为1.54~94.8 ng·g-1,平均值为15.4 ng·g-1.BDE209含量范围为14.4~588 ng·g-1,平均值为136 ng·g-1,占总PBDEs含量的70%以上.钻孔中PBDEs含量从底部到表层呈现上升趋势,表明近年来珠江三角洲PBDEs环境排放仍在增加.5个钻孔中低溴代∑9BDEs从表层至底部逐渐增加,而高溴代∑9BDEs逐渐减少,意味着钻孔中可能存在脱溴降解行为.

To investigate the temporal distribution of polybrominated diphenyl ethers( PBDEs) in the Pearl River Delta,five sediment cores from Pearl River were collected and 10 PBDE congeners were measured using GC /MS. ∑9BDEs( sum of PBDE congeners excluded BDE209) concentrations in the sediment cores were in the range of 1.54 ~ 94.8 ng·g-1with the average of 15.4 ng·g-1. Concentrations of BDE209 were between 14.4 ng·g-1and 588ng·g-1with the average of 136 ng·g-1. BDE209 was the predominant congener accounting for more than 70% of total PBDEs. Increasing trends for PBDE concentration along with the decrease of sediment core depth were observed for all sediment cores,especially in Dongguan reach,indicating an increased emission of PBDEs in study area in recent years. The relative abundance of high brominated PBDEs decreased whereas abundance of low brominated PBDEs increased from top to bottom of sediment cores,which implied a debromination degradation of PBDEs in sediment cores.