title: X-ray Raman spectroscopy of carbon in asphaltene: light element characterization with bulk sensitivity.
abstract: X-ray Raman spectra of the carbon K-edge have been recorded using 6.461 keV radiation for a petroleum asphaltene. By comparison with coronene, graphite, and paraffin standards, the asphaltene spectrum is seen to be composed of contributions from saturated and aromatic carbon species. The information contained in the carbon K-edge was extracted with bulk (approximately 1 mm) sensitivity, because the Raman method used hard X-rays. This helps alleviate concerns about surface artifacts that frequently occur with soft X-ray spectroscopy of light elements. X-ray Raman spectroscopy shows great potential for characterization of light elements in fuels, catalysts, and other complex materials under chemically relevant conditions.
authors.affiliation: Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: U
authors.initials: U
authors.lastname: Bergmann
authors.forename: O C
authors.initials: OC
authors.lastname: Mullins
authors.forename: S P
authors.initials: SP
authors.lastname: Cramer
mesh_terms: D002244:Carbon / Q000737:chemistry*; D006841:Hydrocarbons, Aromatic / Q000737:chemistry*; D010578:Petroleum; D013059:Spectrum Analysis, Raman; D014965:X-Rays
chemical_list: D006841:Hydrocarbons, Aromatic; D010578:Petroleum; D002244:Carbon