Isolation and characterization of the saturate and aromatic fractions of a Maya crude oil

Group separation of Maya crude oil was achieved by the saturates-aromatics-resins-asphaltenes (SARA) method. The sulfur-containing compounds in the saturate and aromatic fractions were then separated using a ligand exchange chromatography method based on organosulfur affinity for Cu2+ and Pd2+, respectively. The separation into group types is effective asa prelude to the structural characterization of crude oil fractions using elemental analysis, Fourier transform infrared, and both H-1 and C-13 nuclear magnetic resonance spectroscopy. In addition, gel permeation chromatography was compared with atmospheric pressure chemical ionization/mass spectrometry (APCI/MS) in order to determine whether the APCI/MS method could provide a rapid means for the determination of the average molar mass.