Chemical characterization of emissions from vegetable oil processing and their contribution to aerosol mass using the organic molecular markers approach

The organic fraction of aerosol emitted from a vegetable oil processing pla nt was studied to investigate the contribution of emissions to ambient part icles in the surrounding area. Solvent-soluble particulate organic compound s emitted from the plant accounted for 10% of total suspended particles. Th is percentage was lower in the receptor sites (less than 6% of total aeroso l mass). Nonpolar, moderate polar, polar, and acidic compounds were detecte d in both emitted and ambient aerosol samples. The processing and combustio n of olive pits yielded a source with strong biogenic characteristics, such as the high values of the carbon preference index (CPI) for all compound c lasses. Polycyclic aromatic hydrocarbons (PAHs) detected in emissions were associated with both olive pits and diesel combustion. The chromatographic profile of dimethyl-phenanthrenes (DMPs) was characteristic of olive pit co mbustion. Organic aerosols collected in two receptor sites provided a diffe rent pattern. The significant contribution of vehicular emissions was identified by CPI v alues (similar to1) of n-alkanes and the presence of the unresolved complex mixture (UCM). In addition, PAH concentration diagnostic ratios indicated that emissions from catalyst and noncatalyst automobiles and heavy trucks w ere significant. The strong even-to-odd predominance of n-alkanols, n-alkan oic acids, and their salts indicated the contribution of a source with biog enic characteristics. However, the profile of DMPs at receptor sites was si milar to that observed for diesel particulates. These differences indicated that the contribution of vegetable oil processing emissions to the atmosph ere was negligible.