不同类型土壤中六溴环十二烷的浓度调查及分布特征比较

Concentration levels and compositional characteristics of hexabromocyclododecane in soils of different areas

六溴环十二烷是一种使用量较高的溴代阻燃剂,具有持久性、生物富集性、半挥发性和高毒性,可在沉积物、水体、土壤和尘埃以及生物体内广泛检出.目前对土壤中六溴环十二烷的分布及浓度的研究主要集中在电子废弃物拆解地等典型高浓度地,而对工业区、养殖区的研究相对较少.实验采用UPLC-MS/MS法检测工业区、养殖区土壤中六溴环十二烷异构体的分布,旨在探明六溴环十二烷在不同类型环境土壤中的浓度及异构体分布差异,以促进对环境中六溴环十二烷的生态危害性的有效评价.结果显示,六溴环十二烷具有较高的检出率(82.00%),工业区土壤中∑HBCDs(α-,β-,γ-HBCD之和)浓度为ND^2.057 8ng·g^(-1)·dw.除去浓度最高点(6.925 8ng·g^(-1)·dw),养殖区土壤中∑HBCDs浓度为ND^1.859 4ng·g^(-1)·dw,普遍低于工业区.养殖区和工业区土壤∑HBCDs浓度均值分别为0.684 6和0.644 8ng·g^(-1)·dw.六溴环十二烷异构体以γ-HBCD为主,与工业品组成相似.部分样品成分分布与工业品组成有差异.

Hexabromocyclododecane(known as HBCDs)is a universal additive brominated flame retardant featuring persistence,bioaccumulation,semi-volatility and high toxicity.Currently,HBCDs has been widely detected in sediments,water,soil,dust and organisms.It enters the environment by a number of different pathways,and then has detrimental effect on the biosphere and even humanity through the material cycle.At present,there are few studies on HBCDs in soil.To investigate the distribution of hexabromocyclododecane in different types of soils,the soils form industrial area and culture area are selected as the object of investigation.This work detects the distribution of hexabromocyclododecane isomers in the soil by UPLC-MS/MS and triple quadrupole low-resolution mass spectrometry.The distributions of hexabromocyclododecane in different types of environmental soils and their isomer’s composition characteristics are obtained.It will promote the effective assessment of the ecological hazards of hexabromocyclododecane in the environment.Our experimental results indicates that the detection frequency of HBCDs is 82%in 50 detected soil samples,and the total HBCDs concentrations in the soils of industrial area and agricultural area range from ND to 2.05 78 ng·g-1·dw and ND to 1.859 4 ng·g-1·dw,respectively.There is a sampling point in the agricultural area whose HBCD concentration is 6.925 8 ng·g-1·dw,but it is not representative.The average concentrations of HBCDs in industrial area and agricultural area are 0.684 6 and 0.644 8 ng·g-1·dw,respectively.Our investigation indicates that HBCDs are common pollutants in different types of soils and there is a significant difference of the contamination of HBCDs in different areas.Compared with the highly-polluted areas such as electronic dismantling plants,the pollution degree of industrial areas and agricultural areas are at relatively low level.The average HBCDs concentration of the industrial area is higher than that of the agricultural area,but the difference is not significant.In the soils the isomeric profiles of HBCDs is similar to commercial HBCD formulations,with theγ-HBCD being the most abundant isomer.The composition of HBCDs in some soil samples is different from that of commercial products.