太湖水体及沉积物中羟基化多溴联苯醚的检测及风险评价

Detection and risk assessment of hydroxyl polybrominated diphenyl ethers in surface waters and sediments of Taihu Lake

羟基化多溴联苯醚(OH-PBDEs)作为一种新型有机污染物具有比母体更大的毒性。针对其在环境中长期蓄积,且对生物体产生更大毒性等问题,采用液相色谱-串联质谱技术(HPLC-MS/MS),分析检测太湖地区25个点位,即水样和沉积物中4种典型污染物羟基化多溴联苯醚(2′-OH-BDE-68、3-OH-BDE-47、5-OH-BDE-47、6-OH-BDE-47)的赋存情况。结果表明:太湖25份水样中均未检出OH-PBDEs,而沉积物中却含有多种OH-PBDEs。同时,检测出的3-OH-BDE-47和5-OH-BDE-47含量较高,最高浓度分别为119 pg·g^(-1)和92.2 pg·g^(-1)。而6-OH-BDE-47检出浓度最低。沉积物中的OH-PBDEs与TOC呈显著正相关,即TOC含量高对OH-PBDEs具有更强的吸附作用。同时,采用风险熵值法开展OH-PBDEs生态风险评价,4种OH-PBDEs在太湖中均为低风险。

As the third largest freshwater lake in China,Taihu Lake plays a decisive role in China′s economic and social development.In view of the existing status of hydroxyl polybrominated diphenyl ethers in the environment,the occurrence of four typical pollutants(2′-OH-BDE-68,3-OH-BDE-47,5-OH-BDE-47,6-OH-BDE-47)in water samples and sediments at 25 points in Taihu Lake was analyzed and detected by liquid chromatography-tandem mass spectrometry(HPLC-MS/MS).The results show that OH-PBDEs were not detected in the 25 water samples of Taihu Lake,but there were many kinds of OH-PBDEs in the sediments.Meanwhile,the contents of 3-OH-BDE-47 and 5-OH-BDE-47 were relatively high,and the highest concentrations were 119 pg·g^(-1) and 92.2 pg·g^(-1),respectively.The detection concentration of 6-OH-BDE-47 was the lowest.The experimental results showed that there was a significant positive correlation between OH-PBDES and TOC in sediments;that is,the high CONTENT of TOC suggested that OH-PBDEs might have a stronger adsorption effect on OH-PBDEs.At the same time,the ecological risk assessment of OH-PBDES was carried out by the risk entropy method,and the results showed that the four OH-PBDEs were of low risk in Taihu Lake.