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Identification of Unanticipated Compounds By High Resolution Mass Spectrometry

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Abstract:Localized outbreaks of acute illness could result from deliberate addition of unanticipated
compounds into water, air, or food. Cancer clusters resulting from long-term exposure to trace-
levels of compounds are more difficult to detect, but can be revealed by epidemiological studies
To find the causative agents in either case, the compounds in sample extracts must be identified
before any contribution they make toward the observed malady can be assessed. Most trace-level
compounds will pose little or no risk. However, all compounds unique to the locality should be
identified, quantified, and classified by their toxicity to ensure that no toxic compounds have
been overlooked.

Sample extracts are often complex mixtures. Separation of components in time by gas
chromatography followed by mass selection of ions using mass spectrometry (GC/MS) provides
distinctive mass spectra for many organic compounds. Mass spectrometer data systems permit
automated searches of mass spectral libraries for each compound's mass spectrum When a
single good match is found, a standard can be purchased, and its mass spectrum and retention
time on the column can be compared with those of the analyte to confirm its identity. But two
problems with this strategy often occur: multiple library matches may provide several candidate
compounds, (1) or worse yet, no matches may be found, since mass spectra for most compounds
are absent from the libraries.
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Citation:Grange, A. H., and G. W. Sovocool. Identification of Unanticipated Compounds By High Resolution Mass Spectrometry. SPECTROSCOPY LETTERS 18(5):12-24, (2003).
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Contact: Chris Siebert - (702) 798-2234 or siebert.christopher@epa.gov
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Division: Environmental Sciences Division
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Branch: Environmental Chemistry Branch
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Product Type: Journal
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Published: 09/02/2003
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Related Entries:
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Bullet Item Advances in Sampling, Separation, Detection and Identification That Address Unmet Needs of Oswer and the Regions
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Last Updated on Monday, October 22, 2007
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