Study On The Analytical Method And Pollution Characterization Of Brominated Flame Reta Dants In Soil From Yellow River Delta

In this study, the former researches about the analytical methods, advanced progress of BFRs in environmental and organism matrix, source apportionment approaches and distribution trends in soils were reviewed comprehensively. The factors influencing recovery were investigated and optimized systematically, an rapid and accurate analytical method for determination of TBBPA and HBCDs in environmental water samples by liquid dispersive microextraction prior to with liquid chromatography coupled with tandem quadrupole mass spectrometry was developed; Another rousted analytical approach for determination of PBDEs, TBBPA and HBCDs in environmental soil was proposed based on the matrix solid phase dispersive technique; The sampling scheme was instituted, and the compositions, distribution trends, pollution levels and spatial distribution of PBDEs, HBCDs and TBBPA in soil from Yellow River Delta were investigated in detail and obtained; The source apportionment of BFRs in soil was carried out by correlation analyses, hierarchical cluster analysis and principal component analysis; The influences of the soil characteristics parameters to distribution of BFRs in soil was studied and the controlling factor was founded out by correction analysis. The study provided a method and theory basis for the research on the mechanism of transportation, transformation and fating of BFRs in soil. This dissertation included the following contents and conclusions:(1).Based on temperature controlled ionic liquid dispersive liquid phase microextraction coupled with liquid chromatography tandem quadrupole mass spectrometry (TCILDLME-LC-MS-MS), two rapid, simple, environmental, sensitive analytical methods for determination of TBBPA and HBCDs were established.①The final optimum conditions for determination of TBBPA are70μL[C6mim][PF6], extraction temperature60℃, extraction time15min, solution pH4and0%salt content. Under above condtions, excellent linearity of TBBPA was obtained in the range of0.5-50μg/L with correlative coefficient (R)0.9987. The limit of detection of TBBPA was0.05μg/L and the relative standard deviation (RSD) was7.70%(n=6). The satisfactory of TBBPA spiked recoveries were in the range of92.4-103.9%and RSDs were in the range of3.31-8.68%.②The final optimum conditions for determination of HBCDs are70μL [C6mim][PF6], extraction temperature75℃, extraction time30min, solution pH6and0%salt content. Under above condtions, good linear relationship, sensitivity and reproducibility of HBCDs were obtained. All the limits of detection for the three diastereomers were10ng/L. The linear range was obtained in the range of1-100μg/L for the total amount of three HBCD diastereomers. It was satisfactory to analyze real environmental water samples with the recoveries ranging from77.2%to99.3%.The advantages of TCILDLME-LC-MS-MS are low cost, avoiding environmental pollution, decreasing the amount of sample, saving the pretreatment time of sample and lessening the heavy labour intensity through the hundreds milliliters organic solvent replaced by several microlitres IL. The results from analysis of the real water samples demonstrated that the proposed methods are high precision, good accuracy and lower level of detection, and can be used widely in environmental monitoring and research.(2).Based on the matrix solid phase dispersive using bamboo charcoal as dispersive sorbent prior to gas chromatography coupled with negative chemical ionic source mass spectrometry (MSPD-GC-NCI-MS), a rapid and sensitive method for determination of PBDEs in soil was developed, and several factors influencing the recovery were investigated and optimized in detailed. Under the optimum condiciotns, the spiked recovery of the PBDEs was in the range71.7-05.9%, and the limits of detection varied from10to80ng/kg (dry weight). Excellent linearity with correlation coefficients (R2) of0.9992-0.9999was obtained over the concentration range of0.10-500μg/kg, except for BDE209, for which the effective concentration range was1.0-5000μg/kg. The results demonstrated that this method can satisfied the requirements of USPEA method1614.(3) An analytical method for determination of TBBPA and HBCD diastereoisomers in soil by MSPD isotopic dilution prior to liquid chromatography coupled with tandem quadrupole mass spectrometry (MSDP-ISD-LC-MS-MS) was proposed. Under the final conditions, the spiked recovery at4,20,80μg/kg level for TBBPA, α-、β-and γ-HBCD were in the range72.8-98.0%,76.8-96.4%,101.9-102.2%and78.1-100%, respectively. The limits of detection were11,75,10,4ng/kg (dry weight) for TBBPA, α-、β-and γ-HBCD, respectively. Excellent linearity with correlation coefficients (R2) of0.996-0.999was obtained over the concentration range of0.80-80μg/kg. The developed method was successfully applied for determination of real soil samples from Laizhou Bay and Yellow River Delta. The results from real samples indicated that the method is sensitive and accurate and suitable for routine analysis.MSPD technique has many merits, including the rapidness, simplicity, low cost and easy operation. The pretreatment time decreased from several hours in conventional method to twenty minutes, to save time and diminish the labour intensity. The isotopic dilution technique can avoid the matrix effects satisfactorily. These methods can be used widely in routine environmental monitor and research in the future.(4).Through a brief analysis of the geography situation, the natural environment, social and economic development of Yellow River Delta, sampling scheme of regional soil was worked out. After analysis of BFRs in soil samplesusing the proposed analytical method, the composition characteristics of BFRs in the surface soil from Yellow River Delta were obtained and as follows:①PBDEs concentration was0.944μg/kg; the concentration of BDE209was0.775μg/kg, accounting for72.5%of the total PBDEs, and is the dominant congener which indicated that PBDEs pollution mainly comes from Deca-BDE; Low brominated biphenyl ether, including BDE28,47,99,153and BDE183, was on behalf of penta-BDE and octa-BDE contributions to the research area of PBDEs. Patterns of penta-BDE in soil are similar with literatures, but slightly different. In this study, the ratio of BDE47and BDE99and Great lake DE-71commodity ratio is closer, which illustrated that the use of Great Lake DE-71industrial products or similar products may be an important source of soils in the Yellow River Delta.②The concentration of TBBPA in soil in the Yellow River Delta is0.601μg/kg; HBCDs concentration was3.734μg/kg with α-and γ-HBCD simultaneity detection. The concentrations of two diastereoisomers showed the correlation although γ-HBCD as the major isomer with accounting for58.21%of HBCDs. Composition of HBCDs diasteroisomers indicated the emission source of HBCDs industrial products in the study area, however, the degradation, transformation or other environmental change maybe exist in the specific sampling sites.(5) Spatial distribution characteristics of BFRs in soils from Yellow River Delta:the concentrations of PBDEs and HBCDs in longitude increased with latitude decreasing gradually, but the increasing trend of TBBPA is not obvious, indicating that PBDEs and HBCDs in the Yellow River Delta mainly sourced from the southern Laizhou Bay BFRs production pollution source by long air routine transfer (LART). TBBPA may come from the sampling point local direct release. The concentrations of BFRs in soil from Yellow River Delta in the horizontal flow with the Yellow River gradually decreased, however, the specific changes of three kinds of BFRs are not completely consistent, which illustrated the transformation efficiency of BFRs source air-soil or input pathways existed differently. Regarding the vertical profile of BFRs, with the increase of soil depth, the concentration of BFRs decreased gradually. Specially, the abundance of low brominated BDE congeners increased, and the composition of HBCD isomers did not significantly change.(6).The pollution level was compared with other researches reported. The concentration of BFRs in Yellow River Delta is close to the similar in neighboring region and many non-point source area in China, and much lower than several regions with obviously BFRs pollution in the world. The pollution levels of TBBPA is lower than in the sediment in Netherland and other foreign river, and also lower than in Wuhan City landfill, however, it is comparable with the lake sediments in American and Norway. The pollution level of HBCDs in soil from Yellow River Delta is close to the urban and farmland soil in Harbin and Guangzhou in China. The overall conclusions are that the BFRs burden in soil of Yellow River Delta is low and comparable with other cities in China and foreign background, and less than USEPA recommended limited standards.(7).The accumulation and inventory of PBDEs, BDE209, TBBPA and HBCDs in soil from Yellow River delta were15.29t,12.55t,9.73t and60.49t, respectively. The results show that inventory of BFRs has reached a certain level. Therefore, the proposal of the corresponding control must to bring forward as early as possible, and early warning and mitigation techniques should be carried out to reduce the environmental hazards caused by BFRs to a minimum.(8).Through the correlation analysis, cluster analysis and principal component analysis, the following conclusions were obtained and as follows:②Deca-BDE and HBCDs have greater contribution to the pollution of BFRs in soil from Yellow River Delta, however, the debrominated transformation of Deca-BDE in the environment with natural light or biodegradable as source cannot be ignored;②Regarding PBDEs source contribution, Deca-BDE has the predomination of PBDEs. Regardingow(BDEs), penta-BDE has domination contribution, otherwise, octa-BDE has second contribution onow (BDEs).③LRAT mode of TBBPA has the smaller contribution, and the main source of TBBPA in research area is the directly releasing from the neighboring production activities.④The migration path of HBCDs and deca-BDE may be the atmospheric near distance transportation to deposit in the surface soil, including the production area of BFRs in Laizhou Bay. However,∑low (BDEs) should be deriving from the long distance input.(9).From the correlation analysis between soil properties and BFRs pollution distribution, the results are that TOC has a significant positive correlation with∑low(BDEs), including BDE28, BDE47, BDE153, and a weak positive correlation with PBDEs, TBBPA and HBCDs. Soil dissolved salt is negatively correlated with BFRs, and no obvious correlation on pH value and sulfur content with BFRs. Therefore, TOC content in soil is the main factors influencing the distribution of BFRs.