Online Coupling of Liquid Chromatography with Fourier Transform Ion Cyclotron Resonance Mass Spectrometry at 21 T Provides Fast and Unique Insight into Crude Oil Composition

Abstract

High magnetic field Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry provides the highest mass resolving power and mass measurement accuracy for detailed characterization of complex chemical mixtures. Here, we report the coupling of online liquid chromatography of complex mixtures with a 21 tesla FT-ICR mass spectrometer. The high magnetic field enables large ion populations to be analyzed for each spectrum for a high dynamic range, with 3.2 million mass resolving power at m/z 400 (6.2 s transient duration) or 1.6 million (3.1 s transient duration) while maintaining high mass accuracy for molecular formula assignment (root-mean-square assignment error < 0.150 ppm). Thousands of unique elemental compositions are assigned per mass spectrum, which can be grouped by the heteroatom class, double bond equivalents (the number of rings and double bonds to carbon), and carbon number. Figures of merit are discussed, as well as characterization of an Arabian heavy vacuum gas oil in terms of the ring number, compound class, double bond equivalents, and ion type. Consideration of elemental composition and retention order provides additional structural information.

Lessons Learned from a Decade-Long Assessment of Asphaltenes by Ultrahigh-Resolution Mass Spectrometry and Implications for Complex Mixture Analysis

“…These features make possible MS data collection with chromatographic resolution while maintaining a high mass accuracy (RMS < 0.150 ppm). Figure a presents a single transient mass spectrum for the HPLC APPI 21 T FT-ICR MS analysis of an Arabian heavy distillate . The HPLC method was an aromatic ring separation that provided six major elution ranges: saturates, 1-ring, 2-ring, 3-ring, 4-ring, 5-ring plus “polar” compounds, and sulfides as shown in the extracted ion chromatogram (Figure b) …”

“…The dotted lines indicate the various fractions and highlight the elution points where the fractions should be collected for direct infusion experiments. [Reproduced with permission from ref . Copyright 2021, American Chemical Society, Washington, DC.…”

Revealing the Reactivity of Individual Chemical Entities in Complex Mixtures: the Chemistry Behind Bio-Oil Upgrading

“…To separate isomeric species, mass spectrometric techniques are typically coupled with chromatographic systems such as ultra-high performance supercritical fluid chromatography (SFC), 14 GC, 15 − 18 ion mobility spectrometry, 19 SFC, 20 , 21 and liquid chromatography. 22 …”

2021 Pioneers in Energy Research: Alan Marshall

“…With the introduction of MagLab’s 21 T FT-ICR mass spectrometer in 2015, petroleum characterization entered a new era, in which online liquid chromatography methods are now coupled to ultrahigh-resolution FT-ICR MS and the most complex mixtures are analyzed . Such performance on a chromatographic time scale was unimaginable in the early days of petroleum research at the MagLab and is poised to make future contributions to petroleum science.…”

“…In a series of publications since 2010, 27−31 36 petroleum characterization entered a new era, in which online liquid chromatography methods are now coupled to ultrahigh-resolution FT-ICR MS and the most complex mixtures are analyzed. 37 Such performance on a chromatographic time scale 38 was unimaginable in the early days of petroleum research at the MagLab and is poised to make future contributions to petroleum science. One of Alan Marshall's greatest contributions to the field is his inspiring vision that instrumentation advances were the key, one shared by a Seminole alumnus and great chemist Mark Wrighton in his Ullyot lecture: "Those who have the highestresolution tools in science can ask the most important questions, and those that have such tools first can answer the important questions first.…”