The method of choice for the analysis of PBDE congeners is high-resolution gas chromatography (HRGC) on a capillary column with detection by an electron-capture detector (ECD) or, preferably, selected-ion-monitoring mass spectrometry (SIM-MS) with the electron ionization (EI) and/or electron-capture negative ionization (ECNI) mode and high resolution mass spectrometry (HRMS).There are, however, problems with the trace level congener specific analysis of PBDEs connected with the overlapping of peaks and the very small signal to noise ratio.