A fast sample pretreatment method was developed to determine polybrominated diphenyl ethers (PBDEs) in polymers from waste electrical and electronic equipment (WEEE). Polymers were firstly prepared into "polymer film" to facilitate a complete Soxtec extraction. Then, three extraction parameters (including hot plate temperature, boiling time, and rinsing time) were optimized based on the recovery of target in reference polymer samples. The proposed method was successfully applied to the analysis of PBDEs in standard plastic materials from WEEE and the extraction yields of PBDEs ranged from 78.9% to 91.3%. The detection limits of PBDEs were 0.05–0.10 µg/g, indicating this method can be used as a quality assurance and quality control procedure of PBDEs in the production of electrical and electronic equipment.

Health risk from exposure of perfluorochemicals to wildlife and human has been a subject of concern in many fields such as environmental ecology, toxicology, pathology and life sciences. The interactions of perfluorooctanoic acid (PFOA) with DNA were investigated by equilibrium dialysis, circular dichroism and isothermal titration calorimetry techniques under normal physiological conditions in vitro. The binding of PFOA to DNA was a non-covalent interaction and corresponded to the Langmuir adsorption isotherm in a two-step binding model, in which PFOA climbed along the backbones of DNA and then interacted with the homolateral bases via hydrophobic interactions. The saturation number of PFOA was calculated to be 0.64 per base-pair of DNA. Such an interaction caused the enhancement of circular dichroism spectra of DNA at both 245 and 275 nm, indicating the change of DNA conformation. The acidic media, low electrolyte and temperature ≦35°C are comparatively more favorable for PFOA binding to DNA. This work provides a useful experimental strategy for studying the interactions of perfluorochemicals with biomacromolecules, aiming at a better understanding of the gene toxicity mechanism of perfluorochemicals.