Laser mass spectrometric analysis of organic atmospheric aerosols. 1. Characterization of emission sources

Carbonaceous aerosol particles stemming from combustion processes play a ke y role in air pollution. Major emission sources include Diesel vehicles, ga soline vehicles, residential heating, wood fires, and cigarettes. The chemi cal characterization of the particles is essential to the identification of their origin. This task can be accomplished using two-step laser mass spec trometry (L2MS). Only small sample quantities are necessary, and the measur ements can be performed within minutes. L2MS was found to be a valuable alt ernative to more laborious chemical analysis techniques that often require extensive sample preparation. Tracer mass spectral patterns were identified , notably based on specific polycyclic aromatic hydrocarbons (PAHs) and oth er polycyclic aromatic compounds (PACs). Their specificity allows the ident ification of different particle emission sources at sites of exposure.