| With the prohibition and phase-out of bromine flame retardants,organophosphate flame retardants are taken as the main substitutes,it's production and usage increased year by year.Organophosphate esters is a kind of main organophosphate flame retardants and plasticizers,they are added mainly to the material with non-chemical bonding,so it increases the chance that these pollutants will transfer into the environment.The available studies found that organophosphate esters had been detected in outdoor atmospheres,indoor dust,surface water,groundwater,sediments and organisms.As a kind of potential persistent organic pollutants,organophosphate esters are attracting more and more attention.At present,the research on the distribution characteristics of organophosphate esters in the environment mainly focuses on the surface water,atmosphere,sediment and other environmental media,but there is less research on environmental dust.Dust is a complex living environment medium,the pollutants attached to the dust may have a direct impact on the human body.Therefore,it is of great significance to study the distribution characteristics of organophosphate esters in environmental dust.This thesis mainly includes the following contents:1.The research background,types,toxicity and pollution status of organophosphorus flame retardants and plasticizers was briefly introduced,and the pretreatment and detection methods f'or organophosphate esters in different environmental media were detailed introduced.2.An effective method was established for the simultaneous determination of ten organophosphate esters in dust by triple quadrupole gas chromatography-mass spectrometer?GC-MS/MS?combined with ultrasound-assisted extraction and solid phase extraction.The conditions of ultrasound-assisted extraction and solid phase extraction,such as variety and dosage of solvents,temperature,time,were optimized in this work.Under the optimal condition,good linearity of ten organophosphate esters can be achievedwhen the analytes are in the corresponding concentration range,and the correlationcoefficients are ranged from 0.9990 to 0.9998,The detection limits of the 10organophosphate esters ranged from 0.44 to 11.08 ng·g-1.The average recoveries of 10organophosphate esters in dust at three spiked concentration levels ranged from 51.4%to123.5%with RSD less than 13.7%.The proposed method had the characteristics of simple operation,high sensitivity and low detection limit made it suitable for the detection of varies organophosphate esters in dust.3.Indoor dust samples collected from several microenvironment,such as office,dormitory,family and archive room,were tested with the optimized analytical method,and the space,time and particle size distribution characteristics of OPEs in microenvironment dust were studied.In different functional microenvironments,there is no obvious regularity in content and distribution,the main influencing factors are the types and quantities of indoor building materials,plastic goods and electrical appliances,the OPEs in the dust will also be affected by environmental factors such as temperature,ventilation and cleaning frequency.In terms of particle size distribution,the dust with particle size range from 25 to 74 ?m accounts for a larger proportion,the amount of OPEs attached to the dust of this unit mass is also higher.4.25 road dust samples were collected from Suzhou,the contamination levels and distribution characteristics of 4 organophosphate esters in the dust samples were analyzed.The exposure to several OPEs and ?OPEs via ingestion and inhalation of dust were also estimated for different population groups,such as average adults,children and professional street sweepers.The experiment results showed that 4 kinds of OPEs were detected in all dust samples with different levels,the concentration of total OPEs ranged from ND to 8901.66 ng·g-1,with a median of 1039.21 ng·g-1.Under a high dust ingestion scenario,the daily intake of ?OPEs via ingestion of dust were 125.68 pg·kg-1 for average adults,915.78 pg·kg-1 for children and 6314.16 pg·kg-1 for professional street sweepers,respectively.Children were found to have 6 times much higher estimated exposure to ?OPEs than average adults.However,the daily intake of OPEs to the dust via inhalation were 3.07E-02?1.89E-02 and 1.54E-01 pg·kg-1 for average adults,children and professional street sweepers,respectively,the gap was small.In general,these findings indicated that the occurrence of OPEs in road dust has greater potential harm to children and professional street sweepers. |
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