Development and Application of Improvements to the Tile-based Fisher Ratio Method and Fundamental Instrument Considerations for Non-targeted Analysis using Two-dimensional Gas Chromatography

Abstract

Comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry GC×GC–TOFMS has arguably made possible the largest increase in gas chromatograph performance since the innovation of the wall-coated open tubular (WCOT) capillary analytical column in 1979. As with the adoption of capillary columns, taking advantage of the performance possible with GC×GC–TOFMS has required the carefully study of fundamental chromatographic parameters and the development of new data analysis strategies and software to leverage the data rich output of the platform for meaningful discovery in complex chemical matrices. This dissertation presents a thorough account the development and validation of the tile-based Fisher ratio software, which aims to provide a robust and efficient method for non-targeted analysis in experiments comprised of classes of GC×GC–TOFMS chromatograms. Additionally, the software is further developed and demonstrated in a unique application to a challenging problem of forensic interest: the chemical characterization of the illicit acid alteration of diesel fuel. Finally, the chromatographic methods used in the development, validation, and demonstration of the software are carefully examined in the context of instrument performance, and compared to alternative instrumental configurations that have the potential to further increase performance.