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AUTOMATED ELEMENTAL COMPOSITION DETERMINATION AND CORRELATION OF PRECURSOR WITH PRODUCT IONS BASED ON ORTHOGONAL ACCELERATION, TIME-OF-FLIGHT MASS SPECTRA
Citation:
SOVOCOOL, G., M. C. ZUMWALT, AND A. H. GRANGE. AUTOMATED ELEMENTAL COMPOSITION DETERMINATION AND CORRELATION OF PRECURSOR WITH PRODUCT IONS BASED ON ORTHOGONAL ACCELERATION, TIME-OF-FLIGHT MASS SPECTRA. Presented at 54th American Society for Mass Spectrometry Annual Meeting, Seattle, WA, May 28 - June 01, 2006.
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:
For more than a decade in our laboratory, elemental compositions of ions in mass spectra havebeen routinely determined by measuring exact masses and relative isotopic abundances of ions in isotopicclusters using a GC coupled to a double focusing mass spectrometer.1 HPLC interfaced to both an accuratemass triple quadrupole and orthogonal acceleration, time-of-flight (oa-TOF) mass spectrometers provide largermass and/or RIA errors than a double focusing mass spectrometer.2,3 To compensate, an Ion CorrelationProgram (ICP) was developed to provide molecular ion or precursor ion compositions, despite the largermeasurement errors. In references 2 and 3, the ICP successfully correlated product and precursor ions andprovided their compositions. In addition, the ICP provided ion non-correlations, so that a simulated compositemass spectrum could be deconvoluted.3 Manual input into the ICP of exact masses, RIAs, and error levels wererequired. This poster reports on an automated ICP that imports ASCII files of m/z ratios and ion chromatogrampeak areas to yield ion compositions and to deconvolute mass spectra.