| Main Title |
Improved Method for Estimating 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-92/133; |
| Stock Number |
PB92-166685 |
| Additional Subjects |
Volatile organic compounds ;
Molecular weight ;
Spectrum analysis ;
Mass spectroscopy ;
Pattern recognition ;
Expert systems ;
Performance evaluation ;
Air pollution ;
Error analysis ;
Reprints ;
|
| Holdings |
| Library |
Call Number |
Additional Info |
Location |
Last
Modified |
Checkout
Status |
| NTIS |
PB92-166685 |
Some EPA libraries have a fiche copy filed under the call number shown. |
|
07/26/2022 |
|
| Collation |
13p |
| Abstract |
An improved method of estimating molecular weights of volatile organic compounds from their mass spectra has been developed and implemented with an expert system. The method is based on the strong correlation of MAXMASS, the highest mass with an intensity of 5% of the base peak in a mass spectrum, with the true molecular weight. Linear corrections to MAXMASS, which yield molecular weight estimates, were derived empirically using the expert system. The system is based on a sequential modular design with a primary classifier linked to molecular weight estimators for the resulting six classes. These are non-halobenzenes; chlorobenzenes; bromoalkenes/alkenes; mono- and dichloroalkanes/alkenes; tri-, tetra- and pentachloro-alkanes/alkenes; and others. Performance tests were made with the old and improved expert systems 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 27 spectra taken from actual field gas chromatography/mass spectrometry samples. |
| Supplementary Notes |
Pub. in Jnl. Chemometrics and Intelligent Lab. Systems, v12 p189-200 1991. See also PB90-200676 and PB91-242990. |
| NTIS Title Notes |
Journal article. |
| Title Annotations |
Reprint: Improved Method for Estimating 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 |
216423412 |
| Origin |
NTIS |
| Type |
CAT |
