Research Of Determination Of Polybrominated Biphenyls In Soil And Sediment

As a kind of brominated flame retardants(BFRs),polybrominated biphenyls(PBBs),had been widely used in textile,chemical,electronic and electrical industries,These compounds are persistent,bioaccumulative and capacity for long-range transport,etc.Although the commercial PBBs has been discontinued,they still have a lasting impact on human health and the environment.In this study,a method for the determination of polybrominated biphenyls in soil and sediment was developed using gas chromatography-high resolution mass spectrometry(GC-HRMS)and gas chromatography-tandem mass spectrometry(GC-MS/MS).The details are as follows:In the first chapter,the physicochemical properties of polybrominated biphenyl are briefly introduced.The existing pretreatment and instrumental analysis techniques for polybrominated biphenyls in environmental media were discussed.The advantages and disadvantages of various methods were compared.The control standards for PBBs domestic and overseas were introduced to provide guidance for the establishment of methods in this study.In the second chapter,a method for the simultaneous determination of 20 polybrominated biphenyls in soil and sediment by Soxhlet extraction-multilayer silica gel column purification-GC-HRMS was established.Based on previous studies,this study improved the extraction efficiency of different solvents under soxhlet extraction and finally selected 10% acetone-N-hexane mixed solution as soxhlet extraction solution.Sample extract was purified using a multilayer silica gel column,and the elution curve of polybrominated biphenyl under a multilayer silica gel column was plotted.Under optimized sample preparation conditions,an instrumental method for the analysis of PBB was developed and instrument parameters were optimized.The established method was validated by methodology and the results showed that the linear range of 20 PBBs was between 10 pg/?L to 1000 pg/?L,and the relative deviation of the relative response factor(RRF)was between 2.9% to 15.1%.The method detection limits(MDLs)ranged from 2.57 ng/kg to 135 ng/kg,the inter-assay deviation was in the range of 1.0%~15.1%(n=7).Recoveries of the 20 PBBs spiked in soil and sediment samples with low,medium and high levels were 64.8%±5.5%~156%±7.1%.Established method was applied to detect PBBs in 24 soil and standard sediment samples from an e-waste dismantling site in Zhejiang Province.17 of 20 PBBs were detected(BB-30,BB-52,and BB-77 are not detected)ranged from 3 ng/kg to 488 ng/kg,BB-153 was the major isomer detected,and was detected in 8 samples.In the third chapter,a method for simultaneous determination of 20 polybrominated biphenyls in soil and sediment suing Soxhlet extraction-multilayer silica column purification-GC-MS/MS was established.The tandem mass spectrometry instrumental method was established under the optimized sample pretreatment condition,the conditions of collision gas pressure and collision energy were optimized.The established method was validated by methodology and the results showed that the linear range of 20 PBBs was 10 ~ 1000 pg/?L and the relative deviation of the relative response factor(RRF)was 3.10%~20.1%.The method detection limits(MDLs)were 15~847 ng/kg,with an inter-assay deviation in the range of 2.3% ~ 10.9%(n=7).The recoveries of the 20 PBBs spiked in soil and sediment samples with low,medium and high levels were 62.8±1.2% ~150% ± 8.2%.24 samples were analyzed using this method,four isomers were detected at a concentration ranged from 33.1 ng/kg to 609 ng/kg.The method detection limits(MDLs)of this method is slightly higher than that of the GC-HRMS method,but the ion pair information of the tandem mass spectrometry has a specific response to different isomers and can effectively eliminate the interference of the debromination of the polybrominated biphenyls and show a big advantage to analyze the specific polybrominated biphenyl isomers.