Classification of Atmospheric Individual Aerosol Particles Sampled by Time-of-flight Mass Spectrometry Using Self-Organizing Map
Large amount of data including chemical composition and size information of individual particles would be generated in the measurement of aerosol particles using atmospheric aerosol time-of-flight mass spectrometry( ATOFMS). Our home-made ATOFMS was used to measure the indoor individual aerosol particles in real-time for 24 h,and the obtained mass spectrometric data were clustering analysis by selforganizing map( SOM) because of its ability of vector quantization and data dimensionality reduction. 20classification results were got which included " Calcium-Containing", " Salt+Secondary particles", " Secondary particles", " Organic Amines", " K+-Rich Organics" and " Soil" particles,etc. Compared with previous mass spectrometric methods,SOM is a natural visualization tool,more classification results can be obtained. This classification information would be useful to assess the response and toxicity of atmospheric aerosol particles and identify the origin of atmospheric aerosol particles.