title: Hexabromocyclododecanes in surface sediments from Shanghai, China: spatial distribution, seasonal variation and diastereoisomer-specific profiles.
abstract: The concentrations, spatial distribution, diastereoisomer-specific profiles of hexabromocyclododecanes (HBCDs) in surface sediments from three major rivers in Shanghai as well as the seasonal variation of HBCDs were investigated. The concentrations of total HBCD diastereoisomers ranged from 0.05 to 6.87ngg(-1)dw. Significant spatial distribution of total HBCDs concentrations were observed. The mean concentration of total HBCDs followed the order of Suzhou Creek (2.00ngg(-1))>Huangpu River (1.59ngg(-1))>Yunzao Creek (0.77ngg(-1)). The concentration was a relatively low HBCDs level compared to levels measured in domestic and other parts of the world. The proportions of α-HBCD in sediment samples were generally higher than that of commercial formulations. This might be due to thermal isomerization from γ-HBCD to α-HBCD and slower degradation rate of α-HBCD compared to γ-HBCD in anaerobic conditions. The concentrations of ΣHBCD in the summer were significantly higher than those in the winter (paired t test, p<0.01). This seasonal variation could probably be attributed to a combined effect of temperature and wet deposition. Moreover, a poor and no significant correlation between ΣHBCD levels and TOC content in sediments was observed, suggesting that the spatial distributions of HBCDs were not constrained by the TOC in sediments of Shanghai.
authors.affiliation: Institute of Applied Radiation of Shanghai, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, PR China.
authors.forename: Ming-Hong
authors.initials: MH
authors.lastname: Wu
authors.affiliation: Institute of Applied Radiation of Shanghai, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, PR China.
authors.forename: Jian-Yao
authors.initials: JY
authors.lastname: Zhu
authors.affiliation: Institute of Applied Radiation of Shanghai, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, PR China.
authors.forename: Liang
authors.initials: L
authors.lastname: Tang
authors.affiliation: Institute of Applied Radiation of Shanghai, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, PR China.
authors.forename: Ning
authors.initials: N
authors.lastname: Liu
authors.affiliation: Institute of Applied Radiation of Shanghai, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, PR China.
authors.forename: Bing-Quan
authors.initials: BQ
authors.lastname: Peng
authors.affiliation: Institute of Applied Radiation of Shanghai, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, PR China.
authors.forename: Rui
authors.initials: R
authors.lastname: Sun
authors.affiliation: Institute of Applied Radiation of Shanghai, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, PR China. Electronic address: xugang@shu.edu.cn.
authors.forename: Gang
authors.initials: G
authors.lastname: Xu
mesh_terms: D005591:Chemical Fractionation; D002681:China; D002851:Chromatography, High Pressure Liquid; D056148:Chromatography, Reverse-Phase; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000032:analysis / Q000737:chemistry*; D006842:Hydrocarbons, Brominated / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification; D045483:Rivers / Q000737:chemistry; D012621:Seasons; D021241:Spectrometry, Mass, Electrospray Ionization; D013237:Stereoisomerism; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D006842:Hydrocarbons, Brominated; D014874:Water Pollutants, Chemical; C089796:hexabromocyclododecane
keywords: Diastereoisomer profiles; Hexabromocyclododecanes; Seasonal variation; Sediment; Shanghai; Spatial distribution