title: Application of pyrolysis-mass spectrometry and pyrolysis-gas chromatography-mass spectrometry with electron-ionization or resonance-enhanced-multi-photon ionization for characterization of crude oils.
abstract: A novel analytical system for gas-chromatographic investigation of complex samples has been developed, that combines the advantages of several analytical principles to enhance the analytical information. Decomposition of high molecular weight structures is achieved by pyrolysis and a high separation capacity due to the chromatographic step provides both an universal as well as a selective and sensitive substance detection. The latter is achieved by simultaneously applying electron ionization quadrupole mass spectrometry (EI-QMS) for structural elucidation and [1+1]-resonance-enhanced-multi-photon ionization (REMPI) combined with time-of-flight mass spectrometry (ToFMS). The system has been evaluated and tested with polycyclic aromatic hydrocarbon (PAH) standards. It was applied to crude oil samples for the first time. In such highly complex samples several thousands of compounds are present and the identification especially of low concentrated chemical species such as PAH or their polycyclic aromatic sulfur containing heterocyclic (PASH) derivatives is often difficult. Detection of unalkylated and alkylated PAH together with PASH is considerably enhanced by REMPI-ToFMS, at times revealing aromatic structures which are not observable by EI-QMS due to their low abundance. On the other hand, the databased structure proposals of the EI-QMS analysis are needed to confirm structural information and isomers distinction. The technique allows a complex structure analysis as well as selective assessment of aromatic substances in one measurement. Information about the content of sulfur containing compounds plays a significant role for the increase of efficiency in the processing of petroleum.
authors.affiliation: Joint Mass Spectrometry Centre, Chair of Analytical Chemistry, Institute of Chemistry, University of Rostock, 18059 Rostock, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Otto
authors.affiliation: Joint Mass Spectrometry Centre, Chair of Analytical Chemistry, Institute of Chemistry, University of Rostock, 18059 Rostock, Germany; Joint Mass Spectrometry Centre, Cooperation Group Comprehensive Molecular Analytics, Institute of Ecological Chemistry, Helmholtz Zentrum München-German Research Center of Environmental Health (GmbH), Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany. Electronic address: thorsten.streibel@uni-rostock.de.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Streibel
authors.affiliation: Joint Mass Spectrometry Centre, Chair of Analytical Chemistry, Institute of Chemistry, University of Rostock, 18059 Rostock, Germany.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Erdmann
authors.affiliation: Joint Mass Spectrometry Centre, Chair of Analytical Chemistry, Institute of Chemistry, University of Rostock, 18059 Rostock, Germany; Joint Mass Spectrometry Centre, Cooperation Group Comprehensive Molecular Analytics, Institute of Ecological Chemistry, Helmholtz Zentrum München-German Research Center of Environmental Health (GmbH), Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Sklorz
authors.affiliation: Marine Chemistry, Leibniz Institute for Baltic Sea Research, Warnemünde, Seestrasse 15, 18119 Rostock, Germany.
authors.forename: Detlef
authors.initials: D
authors.lastname: Schulz-Bull
authors.affiliation: Joint Mass Spectrometry Centre, Chair of Analytical Chemistry, Institute of Chemistry, University of Rostock, 18059 Rostock, Germany; Joint Mass Spectrometry Centre, Cooperation Group Comprehensive Molecular Analytics, Institute of Ecological Chemistry, Helmholtz Zentrum München-German Research Center of Environmental Health (GmbH), Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Zimmermann
keywords: Crude oil; Electron ionization; Polycyclic aromatic hydrocarbons; Pyrolysis–GC/MS; Resonance enhanced multi-photon ionization