Compositional Characterization of Acidic Petroleum Constituents Using Negative Ion Mode Electrospray Ionization Coupled with Fourier Transform-Ion Cyclotron Resonance Mass Spectrometry
Direct infusion Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS) is an emerging tool in the characterization of complex mixtures of organic compounds such as petroleum fluids. Ultra-high mass resolution is achieved based on the extremely precise determination of cyclotron frequencies of ions forced on orbits in an ion trap by a high homogenous magnetic field. The achievable mass resolution depends on the strength of the magnetic field. In this protocol we present a method for compositional characterization of acidic petroleum constituents using negative ion mode electrospray ionization coupled with FT-ICR MS. The protocol describes sample preparation, measurement, and data evaluation and presents some examples for the visualization of the complex data sets obtained. We do so by comparing results for two crude oil samples from offshore Norway, one of which has experienced in-reservoir biodegradation while the other has not. Pitfalls of the used methodology and alternative ionization methods are briefly addressed.
Keywords:Acidic petroleum constituents Biodegradation Compositional characterization Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry
We would like to thank the Norwegian Petroleum Directorate for providing the crude oil samples analyzed in the study.
- 2.Brown L, Ulrich A (2015) Protocols for measurement of naphthenic acids in aqueous samples. In: McGenity TJ, Timmis KN, Nogales B (eds) Hydrocarbon and lipid microbiology protocols. Springer protocols handbooks. doi: 10.1007/8623_2015_88
- 6.Marshall AG, Rodgers RP (2004) Petroleomics: the next grand challenge for chemical analysis. Acc Chem Res 37:53–59Google Scholar
- 9.Bae E, Na J-G, Chung SH, Kim HS, Kim S (2010) Identification of about 30,000 chemical components in shale oils by electrospray ionization (ESI) and atmospheric pressure photoionization (APPI) coupled with 15 T Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) and a comparison to conventional oil. Energy Fuels 24:2563–2569CrossRefGoogle Scholar
- 10.Klein CG, Angstrom A, Rodgers RP, Marshall AG (2006) Use of saturates/aromatics/resins/asphaltenes (SARA) fractionation to determine matrix effects in crude oil analysis by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. Energy Fuels 20:668–672CrossRefGoogle Scholar
- 11.Pakarinen JMH, Teravainen MJ, Pirskanen A, Wickstrom K, Vainiotalo P (2007) A positive-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry study of Russian and North Sea crude oils and their six distillation fractions. Energy Fuels 21:3369–3374Google Scholar
- 13.Cho Y, Na J-G, Nho N-S, Kim S, Kim S (2012) Application of saturates, aromatics, resins, and asphaltenes crude oil fractionation for detailed chemical characterization of heavy crude oils by Fourier transform ion cyclotron resonance mass spectrometry equipped with atmospheric pressure photoionization. Energy Fuels 26:2558–2565CrossRefGoogle Scholar
- 15.Smith DF, Rahimi P, Teclemariam A, Rodgers RP, Marshall AG (2008) Characterization of Athabasca bitumen heavy vacuum gas oil distillation cuts by negative/positive electrospray ionization and automated liquid injection field desorption ionization Fourier transform ion cyclotron resonance mass spectrometry. Energy Fuels 22:3118–3125CrossRefGoogle Scholar
- 19.Panda SK, Brockmann KJ, Benter T, Schrader W (2011) Atmospheric pressure laser ionization (APLI) coupled with Fourier transform ion cyclotron resonance mass spectrometry applied to petroleum samples analysis: comparison with electrospray ionization and atmospheric pressure photoionization methods. Rapid Commun Mass Spectrom 25:2317–2326CrossRefPubMedGoogle Scholar
- 24.Shipkova PA, Heimark L, Bartner PL, Chen GD, Pramanik BN, Ganguly AK, Cody RB, Kusai A (2000) High-resolution LC/MS for analysis of minor components in complex mixtures: negative ion ESI for identification of impurities and degradation products of a novel oligosaccharide antibiotic. J Mass Spectrom 35:1252–1258CrossRefPubMedGoogle Scholar
- 29.Kendrick E (1963) A mass scale based on CH2 = 14.0000 for high resolution mass spectrometry of organic compounds. Anal Chem 35:2146–2154Google Scholar