Semi-continuous mass closure of the major components of fine particulate matter in Riverside, CA

The application of newly developed semi-continuous aerosol monitors allows for the measurement of all the major species of PM2.5 on a 1-h time basis. Temporal resolution of both non-volatile and semi-volatile species is possible. A suite of instruments to measure the major chemical species of PM2.5 allows for semi-continuous mass closure. A newly developed dual-oven Sunset carbon monitor is used to measure non-volatile organic carbon, semi-volatile organic carbon and elemental carbon. Inorganic species, including sulfate and nitrate, can be measured with an ion chromatograph based sampler. Comparison of the sum of the major chemical species in an urban aerosol with mass measured by an FDMS resulted in excellent agreement. Linear regression analysis resulted in a zero-intercept slope of 0.98±0.01 with an R2=0.86. One-hour temporal resolution of the major species of PM2.5 may reduce the uncertainty in receptor based source apportionment modeling, will allow for better forecasting of PM2.5 episodes, and may lead to increased understanding of related health effects.