The chemical composition of aerosol particles is a key aspect in determining their impact on the environment. For example, nitrogen (N)-containing particles impact atmospheric chemistry, air quality, and ecological N-deposition. Instruments that measure total reactive nitrogen (N<sub>r</sub> = all nitrogen compounds except for N<sub>2</sub> and N<sub>2</sub>O) focus on gas-phase nitrogen and very few studies directly discuss the instrument capacity to measure the mass of N<sub>r</sub>–containing particles. Here, we investigate the mass quantification of particle-bound nitrogen using a custom N<sub>r</sub> system that involves total conversion to nitric oxide (NO) across platinum and molybdenum catalysts followed by NO-O<sub>3</sub> chemiluminescence detection. We evaluate the particle conversion of the N<sub>r</sub> instrument by comparing to mass derived concentrations of size-selected and counted ammonium sulfate ((NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub>), ammonium nitrate (NH<sub>4</sub>NO<sub>3</sub>), ammonium chloride (NH<sub>4</sub>Cl), sodium nitrate (NaNO<sub>3</sub>), and ammonium oxalate ((NH<sub>4</sub>)<sub>2</sub>C<sub>2</sub>O<sub>4</sub>) particles determined using instruments that measure particle number and size. These measurements demonstrate N<sub>r</sub>-particle conversion across the N<sub>r</sub> catalysts that is independent of particle size with 98 ± 10 % efficiency for 100–600 nm particle diameters. We also show conversion of particle-phase organic carbon species to CO<sub>2</sub> across the instrument’s platinum catalyst followed by a non-dispersive infrared (NDIR) CO<sub>2</sub> detector. We show the N<sub>r</sub> system is an accurate particle mass measurement method and demonstrate its ability to calibrate particle mass measurement instrumentation using single component, laboratory generated, N<sub>r</sub>-containing particles below 2.5 µm in size. In addition we show agreement with mass measurements of an independently calibrated on-line particle-into-liquid sampler directly coupled to the electrospray ionization source of a quadrupole mass spectrometer (PILS-ESI/MS) sampling in the negative ion mode. We obtain excellent correlations (R<sup>2</sup> = 0.99) of particle mass measured as N<sub>r</sub> with PILS-ESI/MS measurements converted to the corresponding particle anion mass (e.g. nitrate, sulfate, and chloride). The N<sub>r</sub> and PILS-ESI/MS are shown to agree to within ~ 6 % for particle mass loadings up to 120 µg m<sup>−3</sup>. Consideration of all the sources of error in the PILS-ESI/MS technique yields an overall uncertainty of ±20 % for these single component particle streams. These results demonstrate the N<sub>r</sub> system is a reliable direct particle mass measurement technique that differs from other particle instrument calibration techniques that rely on knowledge of particle size, shape, density, and refractive index.