Record Display for the EPA National Library Catalog


Main Title Pattern Recognition/Expert System for Mass Spectra of Volatile Toxic and Other Organic Compounds.
Author Scott, D. R. ;
CORP Author Environmental Protection Agency, Research Triangle Park, NC. Atmospheric Research and Exposure Assessment Lab.
Publisher c1992
Year Published 1992
Report Number EPA/600/J-93/322;
Stock Number PB93-229425
Additional Subjects Air pollution detection ; Pattern recognition ; Expert systems ; Toxic substances ; Volatile organic compounds ; Environmental monitoring ; Computer aided analysis ; Concentration(Composition) ; Mass spectroscopy ; Chemical analysis ; Performance evaluation ; Classification ; Design criteria ; Quality assurance ; Molecular weight ; Reprints ;
Library Call Number Additional Info Location Last
NTIS  PB93-229425 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 14p
A system based on principles of pattern recognition has been developed for identifying toxic and other volatile organic pollutants in complex environmental samples. It interprets the most commonly used monitoring data, mass spectral data, and produces a class designation, an estimate of the molecular weight and, if possible, a target pollutant identity. The system was developed and implemented with a very user friendly expert system which operates by asking questions of the user. The system was designed for samples with low concentrations of pollutants, e.g. ambient air samples. The mass spectra of 74 target and 31 other compounds were used to establish the five target and the one unknown classes. The target classes were nonhalobenzenes; chlorobenzenes; bromo- and bromochloro-alkanes/alkenes; mono- and dichloroalkanes/alkenes; and tri-, tetra- and pentachloro-alkanes/alkenes. The molecular weight is very important in eliminating possible identities for unknown pollutants. This system was extensively tested with mass spectra of potential air pollutants, randomly selected compounds, field gas chromatography/mass spectral air pollutant data and with 54,000 other spectra. Classification and identification accuracies from these tests were 90-100% and 96-100%, respectively. The resulting system runs on a personal computer and is very fast.