Evidence for porphyrins bound, via ester bonds, to the Messel oil shale kerogen by selective chemical degradation experiments

Chemical and nanometer-scale structure of kerogen and its change during thermal maturation investigated by advanced solid-state 13C NMR spectroscopy

“…Various analytical methods such as thermal analysis, elemental analysis, degradation methods, FT-IR and solidstate nuclear magnetic resonance (NMR) spectroscopy have been employed to elucidate some aspects of kerogen structures. Chemical and thermal degradation methods may provide biased concepts of kerogen structure (Philp, 1995;Husby and Ocampo, 1997;Gonzalez-Vila et al, 2001) because of structural alterations during analyses. Among nondestructive spectroscopic analyses, NMR spectroscopy is especially suited to provide novel structural insight.…”

Fractionation and speciation of nickel and vanadium in crude oils by size exclusion chromatography-ICP MS and normal phase HPLC-ICP MS

“…9 Knowledge of the size and structure of metal-complexes present is crucial to the choice of porosity of hydrodemetallation catalysts to allow corrective actions during petroleum refining. Most effort has been devoted to the characterisation of porphyrin-type molecules; [10][11][12][13][14] the presence of non-porphyrin molecules in petroleum has been indicated by some authors [15][16][17] but the evidence has been scarce.…”

A case for immunological approaches in detection and investigation of alien life

“…The latter has been shown to be stable at geologically relevant timescales (Huseby & Ocampo 1997), and heme-containing compounds have indeed been identified in fossil remains of a dinosaur (Schweitzer et al 1997). The latter has been shown to be stable at geologically relevant timescales (Huseby & Ocampo 1997), and heme-containing compounds have indeed been identified in fossil remains of a dinosaur (Schweitzer et al 1997).…”