Exhaustive determination of hydrocarbon compound type distributions by high resolution mass spectrometry

Abstract

The need to obtain detailed chemical information about heavy petroleum fractions, where the usefulness of chromatographic separation techniques is limited, has been addressed by using high resolution mass spectrometry (HRMS). A magnetic sector mass spectrometer was used for the experiments. The instrument meets the mass and dynamic range criteria for the analysis of compounds in complex hydrocarbon fractions, but not the resolving power needs for the separation of overlapping mass doublets. A simple and fast method has been developed that permits the calculation of the relative amounts of the ion species in overlapping mass doublets by consideration of the unresolved peak abundance and the difference between the theoretical and measured masses. The exhaustive determination of hydrocarbon compound type distributions is achieved by the sequential comparison of the theoretical masses of compounds with a given formula against those measured in the mass spectrum.

Mass spectrometric characterization of naphthenic acids in environmental samples: A review

“…hydrogen deficiency. Figure 5 shows an example of a bar chart (Roussis, 1999), listing the hydrocarbon compound classes within a complex mixture.…”

“…One form of data analysis, associated with the study of petroleum-related complex mixtures and which has become increasingly common in recent years, is the use of plots based upon the Kendrick mass scale. First developed by Kendrick (1963), the mass scale was used by Hsu, Qian, and Chen (1992) and later by Roussis (1999). The International Union of Pure and Applied Chemistry (IUPAC) mass scale defines 12 C as having a mass of exactly 12 Da.…”

“…Example of the use of a bar chart to illustrate hydrocarbon compound classes within a complex mixture. Reprinted with permission from Roussis (1999) Ions of the same family (i.e., hydrogen deficiency and heteroatom content) will have an identical Kendrick mass defect, although their Kendrick masses will be different. This phenomenon can be utilized when visualizing data.…”

Nonpolar Compositional Analysis of Vacuum Gas Oil Distillation Fractions by Electron Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

“…38 In conventional EI, 70 eV electron beam energy typically generates extensive fragmentation, which is undesirable for separation and identification of components of mixtures. Lowvoltage (10-18 eV) electron ionization coupled with low and medium resolution mass spectrometers 18,39,40 to analysis of aromatic compounds in petroleum-derived materials ranging from gasoline to heavy crude oil since its first introduction by Field and Hastings 41 in 1956. Hsu et al 23 and Guan et al 24 first applied internal low-voltage EI FT-ICR MS to accurate mass measurement of a heavy petroleum distillate (atmospheric pressure boiling range of 343-566 °C).…”

Atmospheric pressure ionization time-of-flight mass spectrometry coupled with fast liquid chromatography for quantitation and accurate mass measurement of five pharmaceutical drugs in human plasma

“…Accurate mass measurement is another important feature provided by API‐TOF techniques. Accurate mass measurements have been determined classically with magnetic sector instruments9 or more recently Fourier transform ion cyclotron resonance MS 10. Recently, TOF systems coupled with API have become popular for mass spectrometers with relatively high resolution and lower cost 11, 12…”