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Title: Vehicle-related hydrocarbon source compositions from ambient data. The GRACE/SAFER method

Journal Article · · Environmental Science and Technology; (United States)
DOI:https://doi.org/10.1021/es00054a013· OSTI ID:7105471
;  [1];  [2]
  1. Univ. of South California, Los Angeles, CA (United States)
  2. Environmental Protection Agency, Research Triangle Park, NC (United States)

The composition of three volatile hydrocarbon sources (emissions from vehicles in motion, evaporation of whole gasoline, and gasoline headspace vapor) have been derived from 550 ambient, hourly concentration measurements of 37 C[sub 2]-C[sub 9] volatile organic compounds (VOC). The measurements were made by automated gas chromatograph in Atlanta, GA, during the summertime of 1990. The source compositions were obtained by a novel combination of graphical analysis and multivariate receptor modeling methodologies: GRACE (Graphical Ratio Analysis for Composition Estimates) and SAFER (Source Apportionment by Factors with Explicit Restrictions). For the relatively unreactive hydrocarbon species, the ambient-derived source compositions were in good agreement with direct source measurements made in Atlanta concurrent with the ambient measurements. The prominence of the whole gasoline profile in the ambient data was an unexpected result. The GRACE/SAFER method may provide a cost-effective alternative to the usual direct source measurement of profiles. 22 refs., 3 figs., 5 tabs.

OSTI ID:
7105471
Journal Information:
Environmental Science and Technology; (United States), Vol. 28:5; ISSN 0013-936X
Country of Publication:
United States
Language:
English