REAL-TIME ANALYSIS OF INDIVIDUAL ATMOSPHERIC AEROSOL-PARTICLES - DESIGN AND PERFORMANCE OF A PORTABLE ATOFMS

Two portable aerosol time-of-flight mass spectrometers (ATOFMS) of ide ntical design are described, These instruments are powerful new tools for providing temporal and spatial information on the origin, reactivi ty, and fate of atmospheric aerosols, Each is capable of analyzing the size and composition of individual particles from a polydisperse aero sol in real-time, Particles are introduced into the instrument through a particle beam interface, sized by measuring the delay time between two scattering lasers, and compositionally analyzed using a dual-polar ity laser desorption/ionization time-of-flight mass spectrometer, Thes e are the first dual-ion TOFMS instruments to utilize a dual reflectro n design, The instruments measure 72 in. long x 28 in. wide x 60 in. h igh and weigh similar to 500 Ib. Pneumatic tires allow them to be tran sported through standard doorways, elevators, and handicap ramps, gran ting access to virtually any location. Furthermore, because of rugged construction they will be able to operate during transport by automobi le, boat, or aircraft.