Photodegradation Of Decabromodiphenyl Ether And Cytotoxicity Analysis

BFR (brominated flame retardant) is an additive widely used in textiles and electronic items. In 2010, the total production of flame-retardants will reach 2.0×105 t in China. The greatest demand for PBDEs in the market is BDE209 (DeBDE). After dumped into environment, BDE209 produces low-brominated biphenyl ethers and is transformed into PBDD and PBDF after photolysis, pyrolysis, biological and microbiological degradation. The degradation products will get easier access entering into organisms and may cause heavier toxicity.The research consists of two parts:Part 1:The analysis of photochemical reaction of BDE209. On the basis of assertion of the BDE209 and its main photochemical primary products under the testing condition of the pure methanol as the mobile phase and the detection wavelength of 254nm, HPLC method to test the BDE209 and the three primary products is established. Through the photochemical degradation studies of BDE209 in four different solvents (degradation rate:chloroform>DMSO>normal hexane>acetone), all the four degradation processes follow the first-order kinetics; after observation of BDE209 added normal reagent, new synthetic nano-material copper oxide, new synthetic nano-material cuprous oxide and nano-material copper oxide and nano-material cuprous oxide after a time of deposit, the results show that copper oxide and cuprous oxide could accelerate BDE209 degradation rate, and all degradation processes follow first-order kinetics. The acceleration effects of nano-materials on BDE209 are obviously better than the ordinary copper oxide. The acceleration rates of different photosensitizers in the same concentration are:double layer nano-cuprous oxide> single layer nano-cuprous oxide>copper oxide>cuprous oxide. With time increasing of nano-materials'settlement, their degradation effect on BDE209 will weaken gradually.Part 2:BDE209 Cytotoxicity research. First the study sets a proper SCGE condition, choosing OliveTailMoment as primary evaluation indicator and other indicators as subsidiary indicators. Then the study explores cytotoxicity of BDE209 and its photodegradation product through SCGE method. The results show that toxicity and concentration of BDE 209 exist certain dose-response relationship:the longer photodissociation time is, the apparently greater genetic toxicity is. Therefore the study can preliminarily infer that BDE209 photodissociation produces intermediate products with greater genetic toxicity. To ensure the toxicity of BDE209,the study contrasting the results of BDE209 and anthracene SCGE outcome shows they both have genetic toxicity and dose-response relationship, but the cytotoxicity of BDE209 is far lower than anthracene in the same concentration.