Determination of Black Carbon in Carbonaceous Particles by Evolved Gas Analysis and Optical Attenuation

摘要: Particulate material collected on filters from ambient air and combustion sources usually appears black because of the presence of light-absorbing graphitic or black carbon (BC). 1 In the atmosphere, the light absorption by these particles can degrade visibility2 and perturb the tropospheric radiation balance. 3, 4 The major climatological changes that have been predicted as a consequence of large-scale urban fires (eg, nuclear winter) are due primarily to light absorption by black carbon. 5 Black carbon may also play a role in atmospheric chemical reactions such as heterogeneous oxidation of S02. 6, 7 Development of accurate and rapid experimental techniques for determination of BC is essential to continue these studies.Most methods for determining of black carbon8 rely on separation of organic carbon (OC) from black carbon by pyrolysis, oxidation, or solvent extraction before determination of BC as CO2 or CH4. In this study, we describe a technique based on temperature-programmed combustion-evolved gas analysis (EGA) of filter samples of carbonaceous particles. This approach is unique in the following