ADVANCED SAMPLING AND ANALYSIS OF FINE PARTICULATES. Final Topical Report which includes semiannual for the period of January 1, 1998 - June 30, 1998

Sampling tests indicated that the polycarbonate filters were marginally acceptable for in-stack fine-particle collection because of their 230 F melting point as well as requiring carbon coating to reduce charging effects. Vitreous carbon substrates, although not porous, have acceptable thermal stability as well as acceptable levels of charging. A porous silver membrane filter is also being considered for future testing. Pure reference samples of secondary aerosols have been successfully been collected on vitreous carbon substrates with good dispersion and found suitable for direct examination by scanning electron microscope (SEM) without prior coating or preparation. These samples will be used to develop optimum SEM measurement and quantification techniques related to the analysis of fine secondary aerosols