ON THE PERFORMANCE OF AN ONLINE TIME-OF-FLIGHT MASS-SPECTROMETER FOR AEROSOLS

An instrument has been developed to analyze the size and chemical comp osition of individual, air-borne particles. The particles are introduc ed into the vacuum chamber of a time-of-flight mass spectrometer where they are detected and sized using an aerodynamic principle. After siz ing, the particles are vaporized by an excimer laser and the resulting ions are analyzed. Experiments have shown that polystyrene particles 1 mu m in diameter are not fully vaporized by the laser pulse. The ins trument has been characterized and some examples of measurements on am bient and artificial aerosols are presented. Coyright (C) 1996 Elsevie r Science Ltd