Accurate measurement of individual particle atomic composition by aerosol mass spectrometry

Advances in instrumentation used for particle compositional analysis have enabled real-time identification and classification of individual particles. However, precise quantitation of individual particle compositions has been elusive. Here we demonstrate that real-time quantitative single-particle compositional analysis is possible. This is illustrated for individual particles of sodium chloride (70 nm), ammonium sulfate (70 nm), and silica (40 - 2000 nm) using a real-time aerosol mass spectrometer. Atomic fractions for major components (>1% concentration) of individual multi-component particles have been measured within -+ 20% accuracy. Trace element detection limits of 20 ppm are also demonstrated when individual particle compositions are ensemble averaged.