Total Dietary Exposure Assessment Of Emerging Brominated Flame Retardants In Beijing

Because increasing production and use of emerging brominated flame retardants (EBFRs), as well as a potential risk to the environment and human health, they have caused worldwide concern. The dietary exposure is the main route of exposure for general population. But there is still a lack of information about EBFRs in China. Therefore, in this paper, analytical methodology for determining 2,3,5,6-tetrabromo-p-xylene (pTBX), pentabromotoluene (PBT), 1,2,3,4,5-pentabromo-6-ethylbenzene (PBEB), hexabromobenzene (HBB), hexachlorocyclopentadienyl-dibromocyclooctane (DBHCTD) and 1,2-bis(2,4,6-tribromo phenoxy)ethane (BTBPE) in dietary food was established. The exposure level in total dietary samples from Beijing of these compounds was assessed, as well as contaminated level from seven other provinces in China. The main work is as follows:1、First, an analytical method was developed for the simultaneous analysis of pTBX, PBT, PBEB, HBB, DBHCTD and BTBPE in dietary food with atmospheric pressure gas chromatography-tandem mass spectrometry (APGC-MS/MS). Target analytes were extracted by accelerated solvent extraction, purified by silica-alumina column and analyzed by APGC-MS/MS in positive mode. The chromatographic peak tailing aimed at high boiling point compounds was improved by connecting a 70cm unpackaged column at the end of analytical column. The method limit of quantification (MLOQ) was lower than 8 pg/g (wet weight). And the recovery studies were performed at three levels ranged from 80.2% to 119.8% with relative standard deviation (RSD) less than 19.6%(n=6);2、Later, dietary exposure assessment of pTBX, PBT, PBEB, HBB, DBHCTD and BTBPE was performed by analyzing the occurrence of them in dietary samples from Beijing. The results indicated that the PBT, PBEB, HBB and BTBPE were detected and the detection rates of HBB and BTBPE in animal-origin samples were higher than those in plant-origin samples with significant differences (P<0.05). The main sources of dietary intake were meats, vegetables, seafood and milk. The exposure level of Beijing residents to six EBFRs were 187.2-397.9 pg/ (kg·BW·d) which indicated low human risk of the six compounds via dietary exposure.3、Lastly, the method was applied to investigated the concentration of EBFRs in animal-origin dietary samples from Jilin, Henan, Sichuan, Jiangsu, Shanghai, Fujian and Guangdong provinces in China. The results indicate that the concentration of EBFRs in sea food from Fujian and Guangdong provinces were relative higher than other provinces. It should be focused on them in later investigation.