| Orthogonal test, genetic algorithm neural network and single factor experiment were used to optimize detection method of decabrominated diphenyl ether (BDE-209) based on dispersive liquid-liquid microextraction (DLLME) method in this paper. Distribution of polybrominated diphenyl ethers (PBDEs) on components of surficial sediments from Songhua River of Jilin City was investigated using selective extraction, sequential extraction, factor analysis and multiple linear regressions. Sequential extraction, sorption dynamics, sorption thermodynamics experiments and linear regression were used to investigate sorption behavior and sorption mechanism of BDE-209onto surficial sediments. Toxity of PBDEs was studied by luminous bacteria, Hartree-Fock metod and multiple linear stepwise regressions. The results of research of this paper were shown as follow:Ionic strength had significant effect on the enrichment factor (EF) and extraction recovery (ER) of BDE-209. In addition, volume of extraction solvents affected the EF of BDE-209as well as ionic strength. The optimum conditions of DLLME was to use10μL of tetrachloroethylene,0.71mL of acetone, pH=5,2.00%of NaCl and5min of extraction time. The ER and peak area of dispersive liquid-liquid microextraction based on the solidification of floating organic drop coupled with ultrasonic-assisted extraction (UAE-DLLME-SFO) was affected by volume of acetone. The optimum UAE-DLLME-SFO was to use1.00g of sediment sample,3mL of acetone,10min of UAE,0.59mL of disperser solvents,20.5μL of undecanol,20%of NaCl,10min of DLLME.PBDEs concentration of sediment samples from downstream sample locations of Songhua River (Jilin City) was higher than samples collected from upstream. BDE-209was principal component of PBDEs in all the sediment samples mentioned above. Commercial deca-BDEs was the primary source of PBDEs in Songhua River (Jilin City), followed by penta-BDEs and octa-BDEs. Sorption ability of BDE-209on components of sediment is higher than the ability of other PBDEs. Interaction of Mn oxides with other sediments components on sorption of PBDEs was inhibition. While the interaction between Fe oxides and organic matters contributed to sorption of PBDEs. The inhibition between Mn oxides and other components of sediments may due to the oxidation of Mn oxides.The BDE-209sorption onto sediments reached maximum after48h of sorption dynamics experement. Elovich model achieved relatively good simulating effect on the dynamics of BDE-209sorption. The predicting effect of Freundlich model on sorption thermodynamic of BDE-209was the best among the3models. Contents of organic matters in sediments were related with the maximum sorption capacitys of sediments to BDE-209. Fe oxides, Mn oxides and organic matters in sediments all showed sorption capacity to BDE-209in water. When the concentration was low, the sorption of BDE-209by sediments was mainly adsorption action. However, the sorption of BDE-209was mainly patitioned into organic matters by the action of patitioning when the BDE-209concentration up to the maximum sorption amounts of sediments to BDE-209can be achieved.Luminous intensity of luminous bacteria decreased and then went steadily after been exposed to BDE-209solution. Weibull model and Logit model are used to fit dose-effect curve of BDE-209to luminous bacteria. Interaction of dimethyl sulfoxide (cosolvent) with BDE-209promoted the toxicity of BDE-209to luminous bacteria. Interaction of BDE-209with Cu or Zn on luminous bacteria was inhibition. The relative binding affinities (RBAs) to aryl hydro carbon receptor (AhR) of PBDEs were mainly explained by polarizabilities and hyperpolarizabilities of PBDEs calculated by Hartree-Fock analysis. The optimized regression model was selected through Adj R2and F. The optimized quantitative structure-activity relationships (QSAR) model included αyz,△a, βyzz, βxxy and αxx. Multi-collinearity among the variables was not found in this model. |
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