ELEMENTAL ANALYSIS OF AIR PARTICULATE MATTER AND APPLICATION TO SOURCE FINGERPRINTING

摘要

Ion beam analysis (IBA) technique, namely proton induced X-ray emission (PIXE) in conjunction with proton induced gamma emission (PIGE) technique has been used to measure about 20 different elements present in coarse (PM_(10-2.2)) and fine (PM_(2.2)) particles in atmospheric air samples. PIXE provided data for selective elements from Al to U while PIGE provided information on elements lighter than Al such as F and Na. These elements cover the most commonly occurring compounds in coarse and fine atmospheric particles at concentration levels above about 1 ng/m~3 of air sampled. Detection limits for the ion beam techniques on polycarbonate filters were typically between 0.02 and 0.2 mg/cm~2 for a 10 minutes of irradiation time. The multi-element capability of PIXE coupled with PIGE enabled to use these elemental concentration measurements for fingerprinting of various coarse and fine particle sources. Principal component analysis method was applied to find out the fingerprint of different sources, responsible for polluting the atmospheric air. These fingerprints included anthropogenic sources such as motor vehicles, biomass burning/brick kiln as well as natural sources such as sea spray and soil dust.