Complex mixture analysis by Fourier transform ion cyclotron resonance Mass Spectrometry: Petrochemical, environmental, and forensic applications

The high mass resolution, high mass accuracy, and tandem mass spectrometry (MSn) capabilities makes Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) an ideal analytical tool for the analysis of complex mixtures.; Several examples that take advantage of these FT-ICR MS performance characteristics are presented within. An instrument's design and construction considerations are introduced and optimized for complex volatile mixture analysis. The first application of the instrument was the analysis of both raw and processed (via hydrodesulfurization) diesel fuels. The high resolution attainable in FT-ICR MS analysis allowed the resolution of multiple peaks at a single nominal mass. Accurate mass measurements of these resolved isobaric species over the entire mass range of interest (50–300 Da), enabled molecular formulas (elemental compositions) to be assigned for all peaks in the broadband mass spectrum. Samples analyzed included gasoline, jet fuels, and the before mentioned diesel fuels.; Research into the modification of hydrocarbon contaminants once released into the environment led to the analysis of bioremediation. Unequivocal evidence of contaminant bioremediation was proven through the use of an 13C uniformly, isotopically labeled food source, and the observation of complete incorporation of these isotopes into all structural components of the cellular lipids.; Lastly, a forensic application of the identification of arson accelerants is presented. An analysis of seven neat arson accelerants and their weathered analogs identified compositional changes useful in their identification in fire debris because the state of the accelerant after prolonged combustion is similar to that of prolonged weathering. A series of test fires were conducted, accelerated with a number of the seven common accelerants analyzed. Mass spectra from the solvent extraction of fire debris collected from two of the test fires were compared to the mass spectral library constructed from the analysis of the seven neat/weathered standards in an effort to identify the accelerant. From the comparison, the accelerants were positively (and correctly) identified despite the presence of hundreds of matrix mass spectral peaks.