Isolation and Characterization of the Saturate and Aromatic Fractions of a Maya Crude Oil

Abstract

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 as a prelude to the structural characterization of crude oil fractions using elemental analysis, Fourier transform infrared, and both 1H and 13C 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.