Chemical characterization of size-selected nanoparticles emitted by a gasoline direct injection engine: Impact of a catalytic stripper

•Catalytic stripper: volatile phase remover in particle emission measurement systems.•Gas phase, polydisperse and size-selected particle chemical characterization.•Laser desorption/laser ionization/mass spectrometry/statistical data processing.•Lowest-size (10–32nm) nanoparticles carry the highest surface organic fraction.•Excellent agreement with real-time in-situ aerodynamic-mass-mobility measurements.