Source apportionment of VOCs, IVOCs and SVOCs by positive matrix factorization in suburban Livermore, California

Abstract. Gas- and particle-phase molecular markers provide highly specific information about the sources atmospheric processes that contribute to air pollution. In urban areas, major of pollution are changing as regulation selectively mitigates some climate change impacts surrounding environment. this study, a comprehensive thermal desorption aerosol gas chromatograph (cTAG) was used measure volatile, intermediate-volatility semivolatile every other hour over 10 d period from 11 21 April 2018 in suburban Livermore, California. Source apportionment via positive matrix factorization (PMF) performed identify The PMF analysis identified 13 components, including emissions gasoline, consumer products, biomass burning, secondary oxidation, aged regional transport several factors associated with single compounds or events unique compositions. gasoline factor had distinct morning peak concentration but lacked corresponding evening peak, suggesting commute-related traffic dominated by cold starts residential areas. More monoterpene monoterpenoid mass assigned product than biogenic sources, underscoring increasing importance volatile chemical products emissions. Daytime isoprene concentrations were controlled sunlight- temperature-dependent processes, mediated strong midday mixing, found be dominant likely only source at night. Biomass burning indicated wood activity remained an important even springtime. This study demonstrates high-time-resolution marker measurements across wide range volatility enable more profiles narrower would allow.