Ruthenium tetroxide oxidation of immature sulfur-rich kerogens from the Nördlinger Ries (southern Germany)

► We use RuO4 oxidation for structural investigation of sulfur-rich kerogens. ► Alkyl-aryl ether groups are present in the kerogen. ► A scarcely reported series of 2-methyl n-alkanoic acid is identified. ► Some of the bound lipids were contributed by sulfate-reducing bacteria.