CHARACTERIZATION OF BROMINATED AND BROMO CHLORO DIBENZO-(P)UNDER-BAR-DIOXINS AND DIBENZOFURANS BY GAS-CHROMATOGRAPHY MATRIX ISOLATION-INFRARED SPECTROMETRY

Reference matrix isolation-infrared (MI-IR) spectra of selected tetrabrominated dibenzo-p-dioxins (DDs), tetrabrominated dibenzofurans (DFs), and mixed bromo/chloro DDs and DFs were recorded and compared to MI-IR spectra of the corresponding fully chlorinated DDs and DFs. The MI-IR absorption bands for the fully brominated and mixed bromo/chloro DDs and DFs exhibit changes in relative intensity and in some cases shift to lower frequencies compared to their fully chlorinated analogs. The capabilities of MI-IR spectrometry for discriminating between positional isomers, which are often difficult to separate chromatographically and to distinguish by high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS), are also demonstrated.