Optimisation and application of polybrominated diphenyl ethers extraction method

The optimal conditions for the extraction of eight polybrominated diphenyl ethers (PBDEs) were determined using 32 factorial design of experiments (DOE). The independent variables were coded at three levels and their actual values were selected on the basis of the preliminary experimental results. DOE consisted of nine runs with three replicates at the central point. A second-order polynomial model was used for predicting the response. After the optimization of the duration of extraction, the ratio of solvents and purification and instrumental parameters, the optimized conditions were applied on the samples taken from the surface layer of soil from 24 potentially contaminated locations (landfills, ex marshalling yard, dump of secondary raw materials and automotive waste). The gas chromatographic analysis with electron capture detection (GC-ECD) was used for the determination of PBDEs. The recovery values of BDE congeners at five concentration levels ranged between 80% and 115%. The total PBDEs concentrations ranged from 4.4 to 729 ?g kg-1 of absolutely dry soil. The suitability of the experiment was proved by comparing the experimental and predicted values of the variable parameters.