Recent advances in petroleum characterization by GC field ionization time-of-flight high-resolution mass spectrometry

Although mass spectrometry has been studied extensively in the past 50 years for analysis of petroleum and other fossil fuels, comprehensive characterization of total petroleum composition across a wide boiling range remains a challenge. In this work, we report our efforts in combining GC separation, field Ionization, and time-of-flight high-resolution mass spectrometry (GC-FI-TOF HRMS) for detailed analyses of petroleum products with a carbon number range of C6-C44. GC separates hydrocarbon molecules by boiling points. FI generates intact molecular ions for both aromatic and saturate petroleum molecules eluting from the GC. The elemental compositions of these molecular ions are consequently resolved and identified by TOF HRMS with a mass resolving power up to 7000 (M/deltaMfwhm) and mass accuracy of +/-3 mDa, which in turn yields chemical information (heteroatomic content, number of rings plus double bond, and carbon number) for the petroleum molecules. The ability to resolve sulfur-containing hydrocarbons is greatly enhanced because of the unique combination.