摘要
六溴环十二烷(HBCDs)是一种被广泛用于建筑业、纺织业和电子产业的溴代阻燃剂。为了比较六溴环十二烷在土壤中的污染特征,采用高效液相色谱-电喷雾串联质谱联用技术同时测定天津污灌区农田土壤与电子产品拆解区土壤HBCDs的异构体和对映体,对其总浓度、异构体组成和对映体选择性进行了分析。电子产品拆解区土壤中HBCDs的浓度范围为1.57～3.76ng·g-1干重,污灌区农田土壤中的浓度范围是9.33～44.6ng·g-1干重,大沽排污河污灌导致农田土壤中HBCDs的浓度明显高于电子产品拆解区土壤。电子产品拆解区土壤中HBCDs异构体组成与工业品中的HBCDs呈现出明显的差异,α-HBCD的比例明显升高,发生了异构体转化;而污灌区农田土壤中HBCDs与工业品中异构体组成类似。HBCDs各异构体的对映体选择性没有明显的规律,而对于β-HBCD,污灌区农田土壤对(+)-HBCD具有选择性,电子产品拆解区则呈现出相反的现象。
Hexabromocyclododecanes（HBCDs）,one of additive brominated flame retardants,are extensively applied in building,textiles and electronics.The distribution and fate of HBCDs in the environment has drawn much attention.In the present study,soils in farmland in a sewage irrigation area and from an electronic product recycling district in Tianjin were sampled.The samples were extracted with 1：1 hexane-acetone in a Soxhlet device for 24 h and cleaned up with concentrated sulfuric acid and silica column.The extracts were analyzed with LC-MS/MS,and HBCD concentration,diastereomer and enantiomer profiles were further analyzed.The concentration of HBCDs in soils from electronic product recycling district ranged between from 1.57 ng·g-1 to 3.76 ng·g-1 dw;and 9.33 ng·g-1 to 44.6 ng·g-1 dw in farmland from agricultural district.The concentration of HBCDs in sewage sludge from the two districts exhibited the same trend.The unexpected higher HBCD concentration in farmland as compared with those from electronic product recycling district could be due to the sewage irrigation from Dagu Drainage Canal.On other aspect,this suggested that HBCDs were not widely used in electric products in China.Diastereomer-specific selectivity occurred in soil from electronic product recycling district with higher α-HBCD ratio as compared to those in technical products with higher γ-HBCD ratio,indicating the transformation between HBCD diastereomers;while this phenomenon was not observed in soils from agricultural district.There was no uniform tendency of enantiomeric selectivity in soils,indicating that the enantiomeric selectivity is determined by multiple processes controlled by variable factors.As for β-HBCD,agricultural soils exhibited enantiomeric selectivity of（＋）-HBCD and vice versa in soils from electronic product recycling district.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2013年第1期63-68,共6页
Journal of Agro-Environment Science
基金
国家自然科学基金(41073087)
