Record Display for the EPA National Library Catalog


Main Title Computer interpretation of pollutant mass spectra /
Author McLafferty, Fred W.,
CORP Author Cornell Univ., Ithaca, N.Y. Dept. of Chemistry.;Environmental Research Lab., Athens, Ga.
Publisher Environmental Research Laboratory, Office of Research and Development, Environmental Research Laboratory, For sale by the National Technical Information Service.
Year Published 1976
Report Number EPA-600/4-76-046; EPA-R-801106
Stock Number PB-262 341
OCLC Number 02730438
ISBN pbk.
Subjects Algorithms ; Information storage and retrieval systems ; Mass spectrometry ; Computer programming ; Information Systems ; Spectrum Analysis, Mass ; Programming (Electronic computers) ; Information Retrieval Systems
Additional Subjects Mass spectra ; Water pollution ; Water analysis ; Soil analysis ; Data retrieval ; Chemical analysis ; Gas chromatography ; Mass spectrometers ; Information retrieval ; Systems analysis ; Algorithms ; STIRS(Self-training interpretive and retrieval system) ; Self training interpretive and retrieval system
Internet Access
Description Access URL
Library Call Number Additional Info Location Last
EJBD ARCHIVE EPA 600/4-76-046 Headquarters Library/Washington,DC 03/25/2014
EJBD  EPA 600/4-76-046 c.1 Headquarters Library/Washington,DC 03/25/2014
EKBD  EPA-600/4-76-046 Research Triangle Park Library/RTP, NC 07/25/2003
ELBD  EPA 600-4-76-046 AWBERC Library/Cincinnati,OH 04/25/1998
ESAD  EPA 600-4-76-046 Region 10 Library/Seattle,WA 03/23/2010
NTIS  PB-262 341 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation viii, 59 pages : illustrations, graphs ; 28 cm.
The objective of this research was to improve systems for computer examination of the mass spectra of unknown pollutants. For this we have developed a new probability based matching (PBM) system for the retrieval of mass spectra from a large data base, and have substantially improved the interpretation of unknown mass spectra using the self-training interpretive and retrieval system (STIRS). PBM was designed as a prefilter to STIRS; if an unknown mass spectrum can be identified with a sufficiently high confidence by PBM, interpretation of the spectrum using STIRS is not necessary. The PBM system provides more efficient retrieval than presently accepted systems; it incorporates a 'reverse search' algorithm, and through the use of weighted mass and abundance data provides a statistically valid prediction of the confidence of the matches found. STIRS has been improved to give a confidence-level prediction of the presence of approximately equal to 200 particular substructural features in the unknown molecule. Extensive studies have been made to improve the data selection for most data classes used by STIRS, resulting in a much higher level of overall system performance. Operation efficiencies of both PBM and STIRS have been improved dramatically so that both require less than 1 minute on a laboratory PDP-11/45 computer. STIRS has been made available for outside use by long-distance phone connections to this PDP-11/45, and recently both PBM and STIRS have been made operational on the Cornell IBM-370/168 so that these are available internationally over the TYMNET computer network system.
"October 1976." Includes bibliographical references (pages 56-58). Prepared by Cornell University, Ithaca, New York, under grant no. Contract Number: R-801106.