Main Title |
Expert System for Estimates of Molecular Weights of Volatile Organic Compounds from Low-Resolution Mass Spectra. |
Author |
Scott, D. R. ;
|
CORP Author |
Environmental Protection Agency, Research Triangle Park, NC. Atmospheric Research and Exposure Assessment Lab. |
Publisher |
c1991 |
Year Published |
1991 |
Report Number |
EPA/600/J-91/207; |
Stock Number |
PB91-242990 |
Additional Subjects |
Mass spectroscopy ;
Volatile organic compounds ;
Molecular weight ;
Spectrum analysis ;
Pattern recognition ;
Gas chromatography ;
Toxic substances ;
Molecular structure ;
Performance evaluation ;
Reprints ;
Expert systems ;
Reference spectra
|
Holdings |
Library |
Call Number |
Additional Info |
Location |
Last Modified |
Checkout Status |
NTIS |
PB91-242990 |
Some EPA libraries have a fiche copy filed under the call number shown. |
|
07/26/2022 |
|
Collation |
15p |
Abstract |
MAXMASS, the highest mass with an intensity of 5% of the base peak in a low resolution mass spectrum, has been found to be linearly correlated with the true molecular weights of 400 randomly selected spectra, yielding a family of parellel lines. A simple expert system using MAXMASS has been developed to estimate molecular weights of unknown volatile compounds from their mass spectra. This is an empirical rule-based system which will run on a personal computer. It consists of a classification module chained to separate molecular weight prediction modules for six classes. These are benzenes; chlorobenzenes; bromoalkenes/alkenes; mono- and dichloroalkanes/alkenes; tri-, tetra- and pentachloroalkanes/alkenes; and unknown (other) classes. The rules were derived from National Institute of Standards and Technology (NIST) reference spectra of 75 target toxic compounds from the first five classes and 32 from the unknown class. Performance tests of molecular weight predictions were made with the expert system and the Self Training interpretive and Retrieval System (STIRS) on NIST reference spectra of the 107 training compounds; on a set of 32 test NIST reference spectra of other compounds found in air samples; on a set of 100 randomly selected NIST reference spectra; and on 30 spectra taken from actual field gas chromatography/mass spectrometry samples. (Copyright (c) 1991 - Elsevier Science Publishers B.V.) |
Supplementary Notes |
Pub. in Analytica Chimica Acta 246, p391-403 1991. |
NTIS Title Notes |
Journal article. |
Title Annotations |
Reprint: Expert System for Estimates of Molecular Weights of Volatile Organic Compounds from Low-Resolution Mass Spectra. |
Category Codes |
99A; 68A |
NTIS Prices |
PC A03/MF A01 |
Primary Description |
600/09 |
Document Type |
NT |
Cataloging Source |
NTIS/MT |
Control Number |
131122015 |
Origin |
NTIS |
Type |
CAT |