Tile-based fisher ratio analysis of (3D GC) GC3-TOFMS detection data (Sonia Schöneich, MDCW 2023)

• 🎤 Presenter: Sonia Schöneich¹, Paige Sudol², Robert Synovec¹ (¹University of Washington, Seattle, USA. ²Naval Research Laboratory, Washington D.C., USA)

💡 Book in your calendar: 15th Multidimensional Chromatography Workshop (MDCW) January 2024

15th Multidimensional Chromatography (MDC) Workshop 2024

Abstract

Comprehensive two-dimensional (2D) gas chromatography with time-of-flight mass spectrometry (GC×GC-TOFMS) is an excellent tool for the analysis of complex samples. However, many analytes remain poorly analyzed with GC×GC-TOFMS, so improvements in instrumentation and data analysis methods are warranted. To address this challenge, comprehensive three-dimensional (3D) gas chromatography with TOFMS detection (GC3-TOFMS) has been developed. Specifically, development of total transfer GC3 (100% duty cycle) boasts improvements in both selectivity and sensitivity relative to GC×GC. However, the 4D data obtained with GC3-TOFMS requires data analysis approaches that efficiently mine the data, especially when comparing numerous chromatograms, such as with Fisher ratio (F-ratio) analysis for the discovery of analytes that significantly differ in concentration between classes.

Herein, we report expansion of tile-based F-ratio analysis originally developed for GC×GC-TOFMS data, now for GC3-TOFMS data, whereby both involve tiling and automated redundant hit removal. While tile-based F-ratio analysis of GC×GC-TOFMS data requires 4 grids in a 2D tiling format, F-ratio analysis for GC3-TOFMS data requires eight grids in a 3D “cube” tiling format to capture the analyte signal plus any retention shifting. Implementation is demonstrated on six replicates of a jet fuel spiked with a mixture of compounds at 400 ppm and six neat fuel replicates. F-ratio analysis of the GC3-TOFMS data discovered nearly all spiked analytes leveraging the selectivity of the third dimension. F-ratio analysis of the GC3-TOFMS data improved discoverability of the spiked analytes relative to the F- ratio analysis of the same data in a GC×GC-TOFMS format.