PM2.5 Inorganic Aerosol Composition

A Particle-into-Liquid Sampler (PILS) coupled to a dual anion/cation ion chromatograph (IC) will be deployed to make semi-continuous measurements of aerosol inorganic components. A PM2.5 µm impactor will be used to select particles smaller than 2.5 µm. Acidic and basic denuders are employed to remove potentially interfering gases (HCl, HNO3, SO2, NH3). The PILS-IC will be run continuously with 20-minute sample integration times, producing 3 samples/hr and 70 samples/day after accounting for the time allocated to daily dynamic blank and calibration measurements. The species measured will include aerosol sodium (Na+), ammonium (NH4+), potassium (K+), magnesium (Mg2+), calcium (Ca2+), chloride (Cl-), nitrate (NO3-), and sulfate (SO42-). The oxalate ion (C2O42-, from either oxalic acid or organic salts) will also be measured. Detection limits for all compounds are nominally 0.01 µg m-3.