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IDENTIFICATION OF UNANTICIPATED COMPOUNDS BY HIGH RESOLUTION MASS SPECTROMETRY
Citation:
Grange, A H. AND G W. Sovocool. IDENTIFICATION OF UNANTICIPATED COMPOUNDS BY HIGH RESOLUTION MASS SPECTROMETRY. SPECTROSCOPY LETTERS 18(5):12-24, (2003).
Impact/Purpose:
Provide state-of-the-science sampling, analysis, separation, and detection methods to allow rapid, accurate field and laboratory analyses of contaminated soils, sediments, biota, and groundwater to support Superfund clean-up decisions. Apply state-of-the-science methods in chemical analysis and data interpretation (e.g., mass spectral interpretation) to actual problems of OSWER, the Regions, and the States, in cooperation with the Las Vegas Technical Support Center as well as by direct contacts with Regional and State employees. Provide technical advice and guidance to OSWER using the environmental chemistry expertise (e.g., mass spectrometry, analytical methods development, clean-up methodology, inorganics, organometallics, volatile organics, non-volatile organics, semi-volatile organics, separation technologies, etc.) found within the branch.
Technical research support for various projects initiated either by Regions/Program Offices or ECB scientists. While these efforts will support the Regions and Program Offices, they cannot be predicted or planned in advance, and may serve multiple duty (e.g., solve real-world problems, serve to ground-truth analytical approaches that ECB is developing, transfer new technology). Many of the activities in this task support requests involving enforcement decisions and therefore are categorized as "environmental forensics".
Description:
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.