Observation of a-pinenene oligomers in ambient wood smoke aerosol particulate

Accurate source apportionment of aerosols requires the identification of markers that are specific for each source. A-pinene oligomers have been proposed as markers for wood combustion. Forest fires and wood combustion contribute significantly to the aerosol burden in the Central Valley of California during the Fall and Winter months. Aerosol samples were collected for 40 days in the Fall of 2004 in the Yosemite National Park to test the validity of a-pinene polymers as a marker to detect and quantify the wood smoke contribution to the ambient aerosol. During the sampling period there were multiple days of smoke influence due to major fires influencing the Central Valley. Analysis was performed using time-of-flight mass spectroscopy and LC/MS/MS spectrometry. Unique peaks were observed in the mass spectra during the fire period. The unique masses observed correlate to the fragmentation of a pinene oligomer and represent a marker for wood smoke in aerosol particles.