Characterization of a catalyst-based conversion technique to measure total particulate nitrogen and organic carbon and comparison to a particle mass measurement instrument

摘要: Abstract. The chemical composition of aerosol particles is a key aspect in determining their impact on the environment. For example, nitrogen-containing impact atmospheric chemistry, air quality, and ecological N deposition. Instruments that measure total reactive nitrogen ( Nr = all compounds except for N2 N2O ) focus on gas-phase and very few studies directly discuss instrument capacity to mass of -containing particles. Here, we investigate mass quantification particle-bound using custom system that involves conversion nitric oxide (NO) across platinum and molybdenum catalysts followed by NO−O3 chemiluminescence detection. We evaluate particle by comparing mass-derived concentrations size-selected counted ammonium sulfate (NH4)2SO4 ), ammonium nitrate ( NH4NO3 chloride NH4Cl sodium NaNO3 oxalate (NH4)2C2O4 ) particles determined instruments that number size. These measurements demonstrate -particle the independent size with 98  ±  10 % efficiency 100–600 nm diameters. We also show efficient particle-phase organic carbon species to CO2 instrument's catalyst a nondispersive infrared (NDIR) detector. However, the application this method atmosphere presents challenge due the small signal above background at high ambient levels common gas-phase carbon compounds (e.g., ). show system an accurate mass measurement its ability to calibrate instrumentation single-component, laboratory-generated, below 2.5  µ m size. In addition agreement with mass measurements an independently calibrated online particle-into-liquid sampler coupled electrospray ionization source a quadrupole spectrometer (PILS–ESI/MS) sampling negative-ion mode. We obtain excellent correlations R2  0.99) mass measured as PILS–ESI/MS converted the corresponding anion nitrate, sulfate, chloride). The are shown agree within ∼  6 % for loadings up 120  g m −3 . Consideration of sources error technique yields overall uncertainty 20 % these single-component streams. These results reliable direct particle differs from other particle instrument calibration techniques rely knowledge size, shape, density, refractive index.