Absorption And Transformation Of Tetrabromobisphenol A And 2,4-Dibromophenol In Aqueous By Plants

Brominated phenolic pollutants are a group of typical pollutants which have attracted the attention of environmental scientists due to their potential bioaccumulation and biological toxicity.Dietary intake is an important way for population exposure to pollutants.Research on the bioaccumulation,translocation,metabolism of brominated phenolic pollutants in plant aided to understand the environmental behavior of brominated phenolic pollutants and to evaluate the population potential exposure risk to the pollutants.This work investigated the concentration of TBBPA and 2,4-DBP in commercially available radish and distribution of pollutants in different tissues of carrot spiked with the two pollutants.The bioaccumulation,translocation and metabolism processes of pollutants in cells and plants were also studied,The results provide the basic data for evaluating the bioaccumulation,translocation,metabolism and ingestion of brominated phenols pollutants through edible plants.(1)The plant and nutrient solution sample pretreatment method was optimized.The sample was filtered through the membrane of 0.22 ?m without column purification.The average recovery ratio was 93%.The target compound was not detected in the method blank.Compared with the traditional five steps pretreatment,the method had the advantages of saving time and high recovery.(2)The average content of TBBPA were 3.0 ng/g,5.5 ng/g,2.8 ng/g in commercially available Daucus carota,Turnip,Red Raphanus sativus,respectively.For 2,4-DBP,they were 0.46 ng/g,0.56 ng/g,0.37 ng/g,respectively.The detection ratios of TBBPA and 2,4-DBP were 88.9% and 72.2%,respectively.The results showed that the commercially available vegetables were generally contaminated by these two compounds.(3)Short term exposure test showed that the ratio between TBBPA in the root and that in stem was about 5:1,and the bioconcentration factor(BCF)of root was0.40;the ratio between 2,4-DBP in the root and that in stem was about 1:1,and the BCF of root was 0.66.Long term exposure experiments indicated that the percentages of pollutants metabolites in the tissue and/or bonding residues were 97.7% and 99.3%in the carrot cells,and 95.9%,93.6% in the carrot plants and 97.1%,90.9% in the Arabidopsis for TBBPA and 2,4-DBP,respectively.(4)In attempt to quality metabolites of 2,4-DBP in plant,2,4-Dibromophenylglucopyranoside was synthesized by 2,4-dibromophenol and2,3,4,6-tetra-o-acetylglucopyranosyl bromide.The structures of the target compound and intermediates were characterized by 1H NMR and IR.The yield was 42.9%.(5)The glycosylation experiment showed that the content of2,4-Dibromophenylglucopyranoside in plant cells rapidly increased from 0 to 57 ng within 2 hours,and then was gradually raised to 153 ng at the end point of 120 hours.Metabolite qualitative analysis showed that 2,4-DBP produced three glycosylation metabolites and two amino metabolites and TBBPA produced two glycosylation metabolites,two amino metabolites and the sulfone metabolite.