Complete chemical analysis of aerosol particles in real-time

摘要

Real-time mass spectrometry of individual aerosol particles using an ion trap mass spectrometer is described. The microparticles are sampled directly from the air by a particle inlet system into the vacuum chamber. An incoming particle is detected as it passes through two CW laser beams and a pulsed laser is triggered to intercept the particle for laser ablation ionization at the center of the ion trap. The produced ions are analyzed by the ion trap mass spectrometer. Ions of interest are selected and dissociated through collision with buffer gas atoms for further fragmentation analysis. Real-time chemical analyses of inorganic, organic, and bacterial aerosol articles have been demonstrated. It has been confirmed that the velocity and the size of the incoming particles highly correlate to each other. The performance of the inlet system, particle detection, and preliminary results are discussed.