Determination of sulfates in diesel particulates
Analytical techniques for the determination of total sulfates in diesel particulates are described utilizing the techniques of total combustion/nondispersive infrared (NDIR) detection and modified extraction/barium perchlorate-thorin titration (BPT). The combustion technique utilizes a commercially available sulfur analyzer (LECO-IR32) that requires less than 15 min for triplicate analysis and has a precision and accuracy of better than +- 5% for filter samples containing from 100 to 10,000 ..mu..g of sulfate. The combustion technique measures soluble and insoluble sulfate such as BaSO/sub 4/ and is not affected by the presence of large quantities of carbon in the particulate sample. The extraction efficiency for sulfates in diesel particulates using standard procedures was found to average 67% for samples containing only trace quantities of anions and 59% for samples containing stoichiometric levels of barium. These procedures have been modified to include ultrasonication with 2-proponal/water in order to overcome the problem of incomplete sulfate extraction. Extracted sulfate samples are then analyzed by using the BPT method. The extraction/BPT method showed an average recovery of 1.02 +- 0.12 (1 sigma) when compared to the combustion technique. ESCA studies showed that the chemical state of the surface sulfur species for the diesel particulates average 93 +- 3% sulfate and 7 +- 3% elemental sulfur.
- Research Organization:
- Ford Motor Co., Dearborn, MI
- OSTI ID:
- 6397167
- Journal Information:
- Anal. Chem.; (United States), Journal Name: Anal. Chem.; (United States) Vol. 53:6; ISSN ANCHA
- Country of Publication:
- United States
- Language:
- English
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54 ENVIRONMENTAL SCIENCES
ALKALINE EARTH METAL COMPOUNDS
BARIUM COMPOUNDS
BARIUM PERCHLORATES
BARIUM SULFATES
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMICAL STATE
CHLORINE COMPOUNDS
COMBUSTION PRODUCTS
DIESEL FUELS
ELECTROMAGNETIC RADIATION
ELECTRON SPECTROSCOPY
EXTRACTION
FILTERS
HALOGEN COMPOUNDS
INFRARED SPECTRA
IONIZING RADIATIONS
OXIDES
OXYGEN COMPOUNDS
PARTICLES
PERCHLORATES
PETROLEUM PRODUCTS
PHOTOELECTRON SPECTROSCOPY
QUANTITATIVE CHEMICAL ANALYSIS
RADIATIONS
SAMPLING
SEPARATION PROCESSES
SPECTRA
SPECTROSCOPY
SULFATES
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES
TITRATION
X RADIATION