Molecular analysis of sulfate species in environmental aerosols using chemical ionization mass spectrometry
Speciation of sulfurous acid, sulfuric acid and ammonium sulfate collected from the aerosol phase on a Fluoropore filter has been readily accomplished using techniques of chemical ionization mass spectrometry combined with thermal separation. Thermal separation of ammonium hydrogen sulfate from ammonium sulfate was not possible. Spectral separation of these species by selective ionization is proposed. Analysis of sulfate aerosols collected from ambient air and catalyzed vehicle emissions is described. It was found that sulfuric acid aerosol was rapidly converted to ammonium sulfate or ammonium hydrogen sulfate in the presence of ambient concentrations of ammonia. Ambient samples collected in the Detroit metropolitan area have been found to contain only trace quantities of sulfuric acid. Sulfate samples collected from a dilution tube into which catalyzed vehicle exhaust was injected were found to contain significant quantities of ammonium sulfate in addition to sulfuric acid. The rate of sulfate specie volatilization from the filter media was found to be markedly affected by the ammonium sulfate particle size on the filter, thus necessitating the generation of appropriate standards. Impregnation of the collection filter with an appropriate material that will convert sulfuric acid upon collection to a species which is unaffected by ambient ammonia concentrations can permit subsequent quantitation of ambient H/sub 2/SO/sub 4/ by mass spectrometry.
- OSTI ID:
- 7292523
- Report Number(s):
- CONF-770205-48
- Resource Relation:
- Conference: Conference of the SAE International Automotive Engineering Congress and Exposition, Detroit, MI, USA, 28 Feb 1977; Related Information: SAE Paper 770063
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
AIR POLLUTION
MONITORING
SULFATES
MASS SPECTROSCOPY
AEROSOLS
AMMONIUM SULFATES
AUTOMOBILES
CATALYTIC CONVERTERS
EXHAUST GASES
SULFURIC ACID
AMMONIUM COMPOUNDS
COLLOIDS
DISPERSIONS
EQUIPMENT
GASEOUS WASTES
HYDROGEN COMPOUNDS
INORGANIC ACIDS
OXYGEN COMPOUNDS
POLLUTION
POLLUTION CONTROL EQUIPMENT
SOLS
SPECTROSCOPY
SULFUR COMPOUNDS
VEHICLES
WASTES
500200* - Environment
Atmospheric- Chemicals Monitoring & Transport- (-1989)
400102 - Chemical & Spectral Procedures