Correlation of FT-ICR Mass Spectra with the Chemical and Physical Properties of Associated Crude Oils

Abstract

In this study, the peaks observed using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) were correlated with properties of crude oils. The correlations were statistically analyzed and graphically presented using Circos diagrams. Numerous peaks with statistical significance (p < 0.05) correlated strongly with elemental sulfur, nitrogen, nickel, and vanadium contents. In addition, a number of peaks correlated with properties such as acidity, gravity, and weight percent of residue after atmospheric residue distillation of crude oils. The correlation agreed well with generally accepted ideas, thereby validating this approach. For example, sulfur-containing classes such as S-1, S-2, and NS correlated positively with sulfur content. Positive correlation denotes that the relative abundance of the peaks containing S-1, S-2, and NS heteroatoms increased as bulk concentrations of sulfur in the samples increased. The O-2 and O-4 classes of compounds, presumably with COOH functional groups, had a strong correlation with total acid number. Subsequent analyses showed some correlations had carbon number and double-bond equivalence dependence. This study clearly shows the correlation between the chemical compositions determined using FT-ICR MS and the chemical and physical properties of crude oils.