| Research background and purpose:Tetrabromobisphenol A(TBBPA)and Hexabromocyclododecane(HBCDs)are the most commonly used organic flame retardants in industrial production.They are concerned as a new type of persistent organic pollutants for that both of them have neurotoxicity,developmental toxicity,endocrine toxicity and other effects on human health.They were generally detected in the air,water,river mud and other natural media.However,there is little research on soil,especially in agricultural soil.This study investigated and established the sample pretreatment and instrument detection methods of TBBPA and three isomers(a-HBCD,p-HBCD,γ-HBCD)of HBCDs in soil.Then,agricultural soil in Guangdong Province was sampled and tested to detect the content,distribution,storage and accumulation situation of these two compounds.Research methods:1.Methods for the extraction and determination of TBBPA and three isomers(a-HBCD,β-HBCD,γ-HBCD)in HBCDs by HPLC-MS-MS were established and identified.2.Sampling of agricultural soil in Guangdong Province.3.The samples were tested by HPLC-MS-MS.4.SPSS software was used to analyze the test results.Results and discussion:1.A rapid,and stable method for the detection of TBBPA and HBCDs in soils by HPLC-MS-MS was establishedand and identified.The detection limits of TBBPA and α-HBCD,β-HBCD and y-HBCD were 0.01,0.02,0.01,0.03 ng·g-1dw respectively,and the recoveries were between 85%and 115%.2.360 soil samples were collected from 18 counties and districts from eastern Guangdong,eastern Guangdong,western Guangdong and the pearl river delta region.3.The concentrations of TBBPA and ∑HBCDs(the sum of a-HBCD,β-HBCD and y-HBCD)ranged from ND to 7.43 and ND to 3.84 ng·g-1dw,with a mean value of 0.608 and 0.68 ng·g-1dw.4.In the 6 cities involved in sampling,the rank of average content of TBBPA was Foshan(0.91 ng·g-1dw)>Zhanjiang(0.90 ng·g-1dw)>Shantou(0.82 ng·g-1dw)>Zhaoqing(0.44 ng·g-1dw)>Huizhou(0.34 ng·g-1dw)>Shaoguan(0.24 ng·g-1dw).According to the average content of∑HBCDs,the rank was Shantou(0.98 ng·g-1dw)>Huizhou(0.97ng·g-1 dw)>Foshan(0.77 ng·g-1dw)>Zhanjiang(0.72 ng·g-1dw)>Zhaoqing(0.35 ng·g-1dw)>Shaoguan(0.28 ng·g-1dw).The above results showed that the concentrations of TBBPA and HBCDs in agricultural soils from the Pearl River delta regions were significantly higher than the mountain areas of North Guangdong province(P<0.001).The spearman correlation coefficient revealed that there was positive correlation between the local annual output value of flame retardants related industry and the content of EHBCDs in agricultural soils(P=0.021,Spearman correlation coefficient = 0.829).5.The average abundance of a-HBCD,β-HBCD,γ-HBCD in the agricultural soils of Guangdong province was 36.1%,9.0%and54.9%,which was different from the proportion of them in industrial products.The result indicated that HBCDs were transformed and rearranged during environmental accumulation.6.The accumulation of TBBPA and HBCDs in the soils was 4.57 t and 5.10 t respectively,which indicated that these two compounds had accumulated to a certain degree in the agricultural soils of Guangdong Province.Analysis conclusion:1.TBBPA and HBCDs are widely detected in farming soils of Guangdong Province.Their concentration is higher than the industrial underdeveloped areas.But the volume of TBBPA and HBCDs has not reached the level of PBDEs yet.2.The distribution of TBBPA and HBCDs has significant regional differences.The concentration of HBCDs is positively correlated with the annual output of flame retardants related industries.3.The three isomers of HBCDs are transformed in the environment. |
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