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A novel TOF-SIMS apparatus was designed and constructed aiming at single small particle analysis. The apparatus consisted of high lateral resolution TOF-SIMS part and SEM function for seeking analytical target. A pulsed Ga-focused ion beam (FIB) was also newly developed for this purpose based on state-of-the art ion optics. Secondary ion yield of Al was 1.8 × 10−2 which is high enough small area analysis, and mass resolution was also acceptable for element analysis. The most prominent feature, lateral resolution, was demonstrated to be 40 nm in actual mapping of an IC cross-section. As an application aerosol particles were analyzed individually.

A portable aerosol sampler was developed by modifying a commercial filter-type sampler. A tandem sampler head was made in order to remove coarse particles in the first stage, and enhance the linear velocity of the air flow in the second stage. Proper collection plate was also discussed by comparing three kinds of materials (Ag plate, ITO glass and Si wafer). Results on SEM observation concluded that Si wafer was appropriate. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) analysis was performed for a particle collected on Si wafer. It was shown that TOF-SIMS analysis was successful and Si + signal from the substrate caused little problem.

Size segregated atmospheric aerosol samples collected from the summer 2000 Montana forest fires, from Hawaiian sea salt, and from an Asian Dust event reaching Salt Lake City, Utah, in April 2001 have been studied. Multivariate statistical analysis has been used to extract information from the SIMS images. Images of the particles have been separated from the image background, which significantly improved our ability to acquire the composition of individual aerosol particles. Montana forest fire aerosol was predominantly submicrometer, well within the respirable range (PM2.5), and had a characteristic surface composition identified as the amides of stearic acid and palmitic acid. Sea salt showed a layered structure of organic compounds on the surface of aqueous NaCl. The Asian Dust event could be clearly distinguished from normal Salt Lake City particulate pollution.