Abstract
In order to investigate chemical fingerprints of different combustion sources, polycyclic aromatic hydrocarbons (PAHs) of airborne particulate samples were collected on three different occasions in Beijing (China), Tokyo (Japan) and Malaysia. Total-PAHs concentrations, including methyl- and dimethylphenanthrenes and sulfur containing hetero-aromatics (PASHs), were found to be the highest in Beijing (winter) samples followed by Beijing (summer), Tokyo, and Malaysia with readings of (405, 437), (20.4, 41.1), (8.43-43.1), and (2.64-42.6)ng/m3, respectively. Some of compositional differences observed could be due to the difference in combustion sources among the three countries rather than environmental alterations. Using ratios of benzo[ghi]perylene to benzo [e] pyrene (BghiP/BeP) and dimethylphenanthrenes to fluoranthene (DMP/Flu), Malaysian aerosols were elucidated from Tokyo and Beijing samples, suggesting high BghiP/BeP and DMP/Flu ratios as potential molecular markers of biomass-burning in the tropical region. Retene and 1,7-DMP/2,6-DMP ratio had previously been suggested as molecular markers for wood- or conifer-burning, were found to be useless in tropical region. Although PASHs were expected as molecular markers for the burning of sulfur-rich coal in China, ratios of PASHs to total-PAHs had showed only a slight enrichment in Beijing (winter) samples which was significantly affected by coal-combustion as compared to other samples in this study.
