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EVALUATION OF METHODOLOGY AND PROTOTYPE TO MEASURE ATMOSPHERIC SULFURIC ACID
Citation:
Snyder, R., T. Reed, AND A. McKissick. EVALUATION OF METHODOLOGY AND PROTOTYPE TO MEASURE ATMOSPHERIC SULFURIC ACID. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/2-77/010.
Description:
A method is being developed to selectively assay ambient sulfuric acid aerosol. The method utilizes the vapor of a volatile amine (or amine derivative) to neutralize the acid as it is collected on a Teflon filter. The amine sulfate thus formed is thermally decomposed at 200C to release sulfur dioxide, or other stoichiometrically related sulfur containing adduct, which is measured by a flame photometric detector. Immediate chemical fixation of the acid lessens the chance of side reactions with other substances on the filter, while the relatively low decomposition temperature eliminates particulate interferences such as ammonium sulfate. Sulfur dioxide is also collected as a reagent complex on the filter but is selectively removed by heating at 100C.