Environmental analysis of chlorinated and brominated polycyclic aromatic hydrocarbons by comprehensive two-dimensional gas chromatography coupled to high-resolution time-of-flight mass spectrometry

Abstract

A method for the analysis of chlorinated and brominated polycyclic aromatic hydrocarbon (Cl-/Br-PAHs) congeners in environmental samples, such as a soil extract, by comprehensive two-dimensional gas chromatography coupled to a high resolution time-of-flight mass spectrometry (GC × GC–HRTOF-MS) is described. The GC × GC–HRTOF-MS method allowed highly selective group type analysis in the two-dimensional (2D) mass chromatograms with a very narrow mass window (e.g. 0.02 Da), accurate mass measurements for the full mass range ( m/ z 35–600) in GC × GC mode, and the calculation of the elemental composition for the detected Cl-/Br-PAH congeners in the real-world sample. Thirty Cl-/Br-PAHs including higher chlorinated 10 PAHs (e.g. penta, hexa and hepta substitution) and ClBr-PAHs (without analytical standards) were identified with high probability in the soil extract. To our knowledge, highly chlorinated PAHs, such as C 14H 3Cl 7 and C 16H 3Cl 7, and ClBr-PAHs, such as C 14H 7Cl 2Br and C 16H 8ClBr, were found in the environmental samples for the first time. Other organohalogen compounds; e.g. polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), and polychlorinated dibenzofurans (PCDFs) were also detected. This technique provides exhaustive analysis and powerful identification for the unknown and unconfirmed Cl-/Br-PAH congeners in environmental samples.