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CHARACTERIZATION OF AROMATICS IN PETROLEUM BY COMBINATION
OF COMPREHENSIVE 2D GAS CHROMATOGRAPH, APPI QUADRUPOLE
ORBITRAP AND FT-ICR MASS SPECTROMETRY
Yunju Cho1 and Sunghwan Kim1*
Kyungpook National University, Chemistry Dept., 80 Daehak-ro, Buk-gu, Daegu,
702-701 Republic of Korea
Abstract
In this study, comprehensive 2D Gas Chromatograph (GC) and atmospheric
pressure photo ionization (APPI) qudrapole orbitrap and Fourier transform ion
cyclotron resonance mass spectrometry (FT-ICR MS) were used to study polyaromatic hydrocarbons (PAHs) in crude oils. Generally, ultrahigh resolution mass
spectrometry (FT-ICR MS) has been used to understand and predict the behavior of
petroleum. However, with FT-ICR MS, detection of chemical compounds in lower
mass range (m/z < 200) is difficult because of limitations in time-of-flight (TOF)
effect. This can result in loss of lighter ions. 2D GC is a powerful technique by which
several thousands of compounds can be identified. 2D GC is basically one of the GC
techniques and has the limitation in detecting high molecular weight compounds.
Therefore, the data provided by 2D GC and FT-ICR MS can be complimentary to
each other. However, combining data obtained with FT-ICR MS and 2D GC MS is
not trivial because of lack of overlapping m/z regions. Orbitrap MS is another high
resolution mass spectrometry that can detect ions higher than 50 m/z and has
enough resolution (140 000 [m/Δm0.5] at 200 m/z) for lighter ions. Therefore, data
obtained from Orbitrap MS can be used to bridge data between 2D GC MS and FTICR MS. There is a correlation observed between distributions of PAHs which were
measured by 2D GC, orbitrap and FT-ICR MS for aromatic fractions of crude and
shale oil samples. By use of this correlation, the structures identified by GC electron
ionization (EI) spectra could be extended to help to understand the structures of oil
compounds identified by orbitrap and FT-ICR MS. Therefore, this study clearly
shows that the three techniques were complementary to each other and the data can
be combined for more complete understanding of petroleums.