Ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry has recently revealed that petroleum crude oil contains heteroatom-containing (N,O,S) organic components having more than 20 000 distinct elemental compositions (CcHhNnOoSs). It is therefore now possible to contemplate the ultimate characterization of all of the chemical constituents of petroleum, along with their interactions and reactivity, a concept we denote as “petroleomics”. Such knowledge has already proved capable of distinguishing petroleum and its distillates according to their geochemical origin and maturity, distillation cut, extraction method, catalytic processing, etc. The key features that have opened up this new field have been (a) ultrahigh-resolution FT-ICR mass analysis, specifically, the capability to resolve species differing in elemental composition by C3 vs SH4 (i.e., 0.0034 Da); (b) higher magnetic field to cover the whole mass range at once; (c) dynamic range extension by external mass filtering; and ...

Petroleomics: The Next Grand Challenge for Chemical Analysis

Mass spectrometry is well-suited for complex mixture analysis, because unlike other types of spectroscopy, the number of mass spectral peaks per analyte is of order one. Here, we extend significantly the upper limit for the number of chemically distinct components resolved and identified in a single step. Specifically, electrospray selectively ionizes only the basic compounds (i.e., a small fraction of the entire chemical composition) in a sample of South American crude oil. Nevertheless, their positive ion Fourier transform ion cyclotron resonance mass spectrum (average mass resolving power of ∼350 000 from 225 to 1000 Da) contains more than 11 100 resolved peaks, of which >75% may be assigned to a unique elemental composition (CcHhOoNnSs). Mass scale expansion and graphical representations reveal increased heteroatom diversity, aromatic rings, and alkyl substitution with increased mass. These results set a new standard and illustrate the potential of high-resolution mass spectrometry for analysis of com...

Resolution of 11 000 Compositionally Distinct Components in a Single Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrum of Crude Oil

Although crude acids are minor constituents in petroleum, they have significant implications for crude oil geochemistry, corrosion, and commerce. We have previously demonstrated that a single positive-ion electrospray ionization (ESI) high-field Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) experiment can resolve and identify 3000 chemically different elemental compositions of bases (basic nitrogen compounds) in a crude oil. Here, we show that negative-ion ESI high-field FT-ICR MS can selectively ionize and identify naphthenic acids without interference from the hydrocarbon background. When combined with prechromatographic separation, ESI FT-ICR MS reveals an even more detailed acid composition. An average mass resolving power, m/Δm50% ≥ 80 000 (Δm50% is mass spectral peak full width at half-maximum peak height) across a wide mass range (200 < m/z < 1000), distinguishes as many as 15 distinct chemical formulas within a 0.26 Da mass window. Collectively, more than 3000 chemically ...

Resolution and identification of elemental compositions for more than 3000 crude acids in heavy petroleum by negative-ion microelectrospray high-field Fourier transform ion cyclotron resonance mass spectrometry

. The present paper is the result of a workshop sponsored by the DFG Research Center/Cluster of Excellence MARUM "The Ocean in the Earth System", the International Graduate College EUROPROX, and the Alfred Wegener Institute for Polar and Marine Research. The workshop brought together specialists on organic matter degradation and on proxy-based environmental reconstruction. The paper deals with the main theme of the workshop, understanding the impact of selective degradation/preservation of organic matter (OM) in marine sediments on the interpretation of the fossil record. Special attention is paid to (A) the influence of the molecular composition of OM in relation to the biological and physical depositional environment, including new methods for determining complex organic biomolecules, (B) the impact of selective OM preservation on the interpretation of proxies for marine palaeoceanographic and palaeoclimatic reconstruction, and (C) past marine productivity and selective preservation in sediments. It appears that most of the factors influencing OM preservation have been identified, but many of the mechanisms by which they operate are partly, or even fragmentarily, understood. Some factors have not even been taken carefully into consideration. This incomplete understanding of OM breakdown hampers proper assessment of the present and past carbon cycle as well as the interpretation of OM based proxies and proxies affected by OM breakdown. To arrive at better proxy-based reconstructions "deformation functions" are needed, taking into account the transport and diagenesis-related molecular and atomic modifications following proxy formation. Some emerging proxies for OM degradation may shed light on such deformation functions. The use of palynomorph concentrations and selective changes in assemblage composition as models for production and preservation of OM may correct for bias due to selective degradation. Such quantitative assessment of OM degradation may lead to more accurate reconstruction of past productivity and bottom water oxygenation. Given the cost and effort associated with programs to recover sediment cores for paleoclimatological studies, as well as with generating proxy records, it would seem wise to develop a detailed sedimentological and diagenetic context for interpretation of these records. With respect to the latter, parallel acquisition of data that inform on the fidelity of the proxy signatures and reveal potential diagenetic biases would be of clear value.

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Selective preservation of organic matter in marine environments; processes and impact on the sedimentary record

Ultrahigh-resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry has resolved and identified the elemental compositions of over 10 000 organic constituents of coal and petroleum crude oil. A plot of Kendrick mass defect versus Kendrick nominal mass sorts compounds into homologous series according to compound class (i.e., numbers of N, O, and S heteroatoms), type (number of rings plus double bonds), and degree of alkylation (number of CH2 groups), to yield unique elemental assignments from ultrahigh-resolution mass measurements in the 200−900 Da range. Interpretation of such a vast compilation requires a simple (preferably graphical) means to differentiate between complex organic mixtures of different origin or processing. In an extension of the recently revived van Krevelen plot, each elemental composition is projected onto two or three axes according to its H/C, O/C, and/or N/C atomic ratios. The H/C ratio separates compounds according to degree of saturation, wher...

Two- and Three-Dimensional van Krevelen Diagrams: A Graphical Analysis Complementary to the Kendrick Mass Plot for Sorting Elemental Compositions of Complex Organic Mixtures Based on Ultrahigh-Resolution Broadband Fourier Transform Ion Cyclotron Resonance Mass Measurements

Petroporphyrin compositional analysis of a heavy crude oil has been realized by isolation and subsequent ESI-FT-ICR mass spectrometric analysis of the porphyrin-containing fractions. Vanadium octae...

Mark Greaney

Papers

Molecular characterization of petroporphyrins in crude oil by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry