Characterization of Unsubstituted and Methylated Polycyclic Aromatic Hydrocarbons and Screening of Potential Organic Compounds in Solid Waste and Environmental Samples by Gas Chromatography–Mass Spectrometry

Concentrations of 19 polycyclic aromatic hydrocarbons (PAHs) and 15 methylated derivatives (Me-PAHs) were determined in different solid waste and environmental samples collected from Japan and Vietnam. Total levels of PAHs and Me-PAHs were the highest in vehicular soot samples (12,000-800,000 ng/g), followed by settled dusts (940-1,700 ng/g), and ash samples (100-270 ng/g). Fingerprint profiles of PAHs and Me-PAHs were characterized for the examined samples: the ash samples were dominated by low-molecular-weight compounds (2-3 rings) while the dust and soot samples exhibited significant proportions of high-molecular-weight PAHs (≧ 4 rings). Our results provide basic information about the occurrence of PAHs in vehicular exhausts (especially gasoline-powered vehicles) and their impacts on environmental contamination levels in a typical developing country as Vietnam. The samples were also screened for potential major organic substances by using GC-MS scan mode, revealing several specific pollutants in each sample type. Based on the analytical results, preliminary discussions about source apportionment and human health risk assessment of organic pollutants were addressed with a focus on PAHs and Me-PAHs. More comprehensive investigations of multiple organic contaminant classes in a wide variety of source-related samples and environmental compartments are needed.