FTICR Organic Matter Characterization

Un-targeted FTICR-MS analysis yields a substantial amount of raw data. The spectra are analyzed to determine possible molecular formulae and these data visualized in Kendrick mass defect plots, Van Krevelen diagrams, and mapped to KEGG metabolic pathways. The visualizations are all interactive, allowing the user to select features to display, zoom in and out, and hover over data points to view the underlying information.

Kendrick Plot

Kendrick mass defect plots distinguish homologous compounds that differ by a number of base units. Ions of the same homologous series have the same Kendrick mass defect but different nominal Kendrick mass and are positioned along a horizontal line on the plot.

Kendrick Plot

Van Krevelen Diagram

Van Krevelen diagrams plot the H:C vs. O:C ratios of the molecular formulae, thus representing a sample’s composition and showing the localization of metabolite classes.

Van Krevelen diagram

KEGG Pathway Maps

The molecular formulae that map to KEGG compounds are displayed in the context of KEGG pathway modules.