You are here:
ION COMPOSITION ELUCIDATION (ICE)
Citation:
Grange, A H. AND G W. Sovocool. ION COMPOSITION ELUCIDATION (ICE). Presented at The 17th Asilomar Conference, Pacific Grove, CA, October 19-23, 2001.
Impact/Purpose:
The overall goals of the task are to apply NERL's core capability in advanced chemical science and technology for maximum benefit in estimating exposures of ecosystems and humans to chemical stressors and to identify emerging pollution concerns, in particular long-range airborne transport of contaminants. This task comprises several subtasks, each with individual objectives:
Subtask 1: screen exposures of National Park PRIMENet ecosystems to chemical stressors, identifying indications of exposure requiring further evaluation, and use these samples evaluate new analytical methods as replacements for standard methods in future assessments of ecosystem contaminant exposures.
Subtask 2: evaluate a new mercury analytical approach with superior performance on complex solid matrices such as biological tissues, and apply the approach to estimating exposure of ecosystems and humans to mercury.
Subtask 3: determine distribution patterns of chemical contaminants in the southern Sierra Nevada Range of California, investigate topographic and weather factors that may influence the distributions, and determine if a correlation exists between contaminant distributions and extirpation patterns of the mountain yellow-legged frog.
Subtask 4: provide analytical methods to measure a number of inorganic and organic arsenic species in a variety of environmental matrices, elucidate the environmental transformations undergone by organoarsenic animal-feed additives, and determine if the potential exists for substantially increased exposure of humans and aquatic organisms to arsenic.
Description:
Ion Composition Elucidation (ICE) utilizes selected ion recording with a double focusing mass spectrometer to simultaneously determine exact masses and relative isotopic abundances from mass peak profiles. These can be determined more accurately and at higher sensitivity than with high resolution employing conventional scanning mass spectrometry. The technique can be applied to trace concentrations of analytes eluting from complex environmental mixtures. ICE has two facets: Mass Peak Profiling from Selected Ion Recording Data (MPPSIRD) for data acquisition and a Profile Generation Model (PGM) for automated composition assignment. MPPSIRD and the PGM will be described and a number of applications of ICE to the structural identification of "unknowns" will be shown. Environmental forensics can benefit greatly from expedited identification of "mystery" pollutants and biomarkers of exposure/effects.