珠江三角洲流域土壤多溴联苯醚(PBDEs)的分布及环境行为

The distribution and the environmental fate of polybrominated diphenyl ethers in watershed soils of Pearl River Delta

用索式抽提、复合硅胶/氧化铝层析柱分离纯化、GC-MS分析方法分析了珠江三角洲流域土壤中10种多溴联苯醚(BDE-28、-47、-66、-99、-100、-153、-154、-138、-183、-209)在土壤中的质量分数和组成分布。∑9PBDEs(不包括BDE209)的质量分数从0.133ng·g-1干物质量到3.81ng·g-1干物质量,平均质量分数为1.02ng·g-1干物质量,BDE-209的质量分数从2.38ng·g-1干物质量到66.6ng·g-1干物质量,平均质量分数为13.8ng·g-1干物质量,与欧洲背景土壤中PBDEs的质量分数水平相当。同系物的组成分布说明珠江三角洲土壤中多溴联苯醚的污染来源主要是五溴、八溴及十溴产品的使用。土壤中∑9PBDEs和各同系物的含量与土壤总有机碳(TOC)的含量呈现显著的正相关。有机碳均一化后BDEs单体含量的对数与其logKow正相关(除-47,r2=0.89),表明土壤有机质的吸附决定着PBDEs在环境中的分布和迁移。

The concentrations and distributions of 10 PBDE congeners （BDE-28, -47, -66, -100, -99, -154, -153, -138, -183, and -209） in watershed soils of Pearl River Delta were analyzed sequentially by Soxhlet extraction, multilayer silica/alumina chromatography column purification and GC-MS determination. The contents of ∑9 PBDEs （excluded BDE-209） and BDE-209 in soils ranged from 0.133 ng·g-1 dry weight （dw） to 3.81 ng·g-1 dw, with a mean value of 1.02 ng·g-1 dw, and 2.38 ng·g-1 dw to 66.6 ng·g-1 dw, with a mean value of 13.8 ng·g-1 dw, respectively, which were at the same level as those in background soils in Europe. The compositional profiles indicated that the main sources of PBDEs in PRD were the usage of penta- octa- and deca-BDEs. ∑9 PBDEs or each BDE congener had a significant correlation with the total organic carbons （TOC） of the soils. In addition, a good regression （except for -47） between the logarithms of TOC-normalized BDE average contents and their log Kow was also obtained （r2=0.89）, indicating that the sorption of PBDEs on soil organic matter governed their spatial distribution, and transportation in the soils.