Abstract
Atmospheric aerosols and particulate matter from a wide variety of emissions sources measurements are conventionally performed by recording PM mass. The ambient standards are written in terms of mass concentrations, and emission regulations are based on mass rates. However, in order to understand better the nature of the mobile source contribution to ambient PM, many research groups are currently extending their investigations to include measurements of the speciation of particles in automotive exhaust.
Usually, organic fraction of automotive exhaust particles are concentrated to 1 mL by Kuderna-Danish concentrator after extracted into dichloromethane by soxhlet extraction. Then, these extracts are analyzed by GC/MS. In this time, it need long time to get analytical results although we can get precise results.
Progress in understanding and mitigating these problems is limited by the ability of existing instruments to provide real-time, size-resolved, quantitative measurements of aerosol mass and chemical composition. A number of measurement techniques possessing some of the required aerosol analysis capabilities have emerged recently. Real-time aerosol mass spectrometers aim to provide information on chemical composition of particle ensembles. Most of these instruments also provide information on particle size.
An Aerosol Mass Spectrometer (AMS) developed at Aerodyne Research, which has been designed to provide real-time quantitative information on size-resolved mass loadings for semi-volatile chemical components present on ambient aerosol particles. In this study, semi-volatile chemical composition of automotive exhaust particles are continuously measured by improved aerosol mass spectrometer. In this result, it is found out that diesel exhaust particles semi-volatile size resolved chemical compositions are changed according to driving condition.
Keywords:Automotive exhaust particle, Speciation, Aerosol mass spectrometry, Diesel exhaust, Continuous measurement