Analysis Of The Distribution And Reserves Of New Brominated Flame Retardants In The Sediments Of The Yellow River Delta

There are more and more serious environmental problems with large usages of persistent organic pollutants(POPs).Some countries and international organizations began to eliminate or restrict the use and production such as polybrominated diphenyl ethers(PBDEs)and polychlorinated biphenyls(PCBs).However,new brominated flame retardants(BFRs)included tris(2,3-dibromopropyl)isocyanurate(TBC),hexabromocyclododecanes(HBCDs)and tetrabromobisphenol A(TBBPA)have been widely used in petroleum chemical industry,machinery manufacturing,electrical and electronic products manufacturing industry.Researches shows that they have similar Persistent organic pollutants(POPs)properties,and ubiquitous present in the environment.In this study,Yellow River delta wetland was used as environment model to study the pollution level,constitution characters,the correlation between with TOC,reserves estimation and risk for exposure to TBC and HBCDs.The main content and results of this research were summarized as follows.1.In this experiment optimized pretreatment and detection method of TBC and HBCDs.The pretreatment for the samples was included freeze drying,soxhlet extraction,composite silica gel chromatography,rotary evaporation and nitrogen blow enrichment.Finally,UPLC-MS-MS were used to analysis the sediment samples.The sample standard addition recovery experiments were conduct to ensure the experimental accuracy.[13C12]-α-,β-,γ-HBCD were served as the recovery standard in all sediments and the recovery rates were 88-102%,93-107%,83-98%,respectively.The range of relative standard deviation(RSD)was 4.73-9.11%.2.The experimental results indicated that the detection rate of TBC was 100%,the content was 0.20-29.03 ng·g-1and the average content was 6.88 ng·g-1.The detection rates of α-,β-,γ-HBCD were 75%,71%,96%,respectively.The mean content were 0.69 ng·g-1,0.42 ng·g-1,5.20 ng·g-1and the percentage were 10.1%(5.7–17.0%),6.1%(3.0–12.1%),83.8%(73.2–100.0%)for α-,β-,γ-HBCD.3.The average content of HBCDs(10.46 ng·g-1)was relatively high in river estuary sampling,and the content of TBC and HBCDs were lower along the Yellow River course sampling.The reason might be the pollution from the upstream of Yellow River didn’t flow through the old course of Yellow River,and it could not deposited along with the sediment runoff.In addition,old course of the Yellow River was protected by the government.Moreover,long-range transport for air was one way of TBC and HBCDs migration,however,contamination sources was the mainly way.4.Correlation analysis for detected results was carried out by SPSS 17.0.The correlation analysis of TBC and HBCDs shows that among the three isomers of HBCDs were significant correlation,but TBC with α-,β-,γ-HBCD were weakly correlation.This result indicated that the pollution sources of TBC and HBCDs might be different.There were weakly positive correlation in TOC and TBC,HBCDs.The correlation coefficients of TOC with BFRs were r=0.154(p=0.473),r=0.138(p=0.522),r=0.023(p=0.917),r=0.295(p=0.162),r=0.275(p=0.194)for TBC,α-HBCD,β-HBCD,γ-HBCD,ΣHBCDs.This result shows that the total organic carbon(TOC)in the sediment was one of the factors affecting the distribution of BFRs.Reserve estimates of TBC,α-,β-,γ-HBCD and ΣHBCDs were conducted in Yellow River Delta wetland sediments.In addition,exposure ways of TBC and HBCDs were analyzed including occupational exposure and amateur exposure(skin absorbing exposure,absorbing exposure,diet intake,etc).In order to further understand the levels of TBC and HBCDs in the Yellow River delta wetland sediments,compare with the Jiaozhou Bay wetland.The result indicated that TBC content was nearly two times higher than the Jiaozhou Bay.Compared with other areas of the world the Yellow River Delta wetland HBCDs content was(8.40ng?g-1)in the medium level.