SUPERCRITICAL FLUID CHROMATOGRAPHY COUPLED WITH
ION MOBILITY-MASS SPECTROMETRY: A NOVEL APPROACH
FOR PROFILING OF PETROLEUM SAMPLES
Eleanor Riches1, Yunju Cho2, Sunghwan Kim2
1
Waters Corporation, Stamford Avenue, Altrincham Road, Wilmslow, Cheshire, SK9 4AX, UK. 2Department of Chemistry,
Kyungpook National University, Daegu, South Korea
INTRODUCTION
Oil and petroleum samples present some of the
most complex analytical challenges encountered
by today’s scientists. Typically, high resolving
power mass spectrometers such as FTICR-MS1
are used for comprehensive characterisation
studies at the molecular level; however, recent
work has shown ion mobility-mass spectrometry
(IM-MS) to be a potentially complementary
approach,2,3,4 which enables the acquisition of
information about the distribution of sizes and
shapes of molecules within a sample.
Furthermore, various chromatographic techniques
are well
established for petroleum analyses,5 which can
help to separate complex samples into different
classes or groups depending on the technique
used. The ability to reduce the complexity of a
petroleum sample prior to its introduction into
the mass spectrometer enables greater coverage
of the multifarious components present and
increases the overall peak capacity of the system.
The sequential coupling of chromatography with
ion mobility separation and high resolution mass
detection potentially affords the greatest amount
of total resolution due to the different separation
mechanisms employed by each technique.
METHODS
SYNAPT G2-Si HDMS conditions:
Ionization mode :
Capillary voltage (ESI):
Repeller voltage (APPI):
Cone voltage:
Desolvation temperature:
Desolvation gas flow:
Cone gas flow:
IMS Wave velocity:
IMS Wave height:
IMS cell pressure:
ESI+ or APPI+
3.0 kV
1.0 kV
80 V
450 °C
800 L/Hr
10 L/Hr
1000 m/s (fixed)
40 V
3.3 mbar
Sample:
Arabian Heavy oil, maltenes fraction, 5 mg/mL in Hexane
Data Acquisition and Processing:
Data were acquired using MassLynx v4.1 and processed using
MassLynx v4.1, DriftScope v2.8, and PetroOrg S-8.4.46
ACQUITY UPC2 (SFC) conditions:
Mobile phase A:
Mobile phase B:
Injection volume:
Columns used:
In this work, we couple supercritical fluid
chromatography (SFC) to IM-MS to investigate
the benefits of a multidimensional separation
approach to petroleum characterisation.
Column Temperature:
Gradient:
Dopant for APPI:
TO DOWNLOAD A COPY OF THIS POSTER NOTE, VISIT WWW.WATERS.COM/POSTERS
Carbon Dioxide
1:1 Toluene:MeOH or 100% Toluene
5 μL
ACQUITY UPC2 Torus 1-AA, 1.7 μm,
2.1 mm x 100 mm
ACQUITY UPC2 Torus DEA, 1.7 μm,
2.1 mm x 100 mm
ACQUITY UPC2 HSS C18 SB, 1.7 μm,
3.0 mm x 100 mm
ACQUITY UPC2 BEH C18, 1.7 μm, 3.0
mm x 100 mm
40 °C (column evaluation), 60 °C
(further work)
see Table 1 (column evaluation), see
Table 2 (further work)
1:1 Toluene:MeOH + 500 pg/μL
Leucine Enkephalin, introduced via
the Isocratic Solvent Manager (ISM),
flow rate 0.3 mL/min
1
METHOD
Table 1. UPC2 gradient for column evaluation (B = 1:1 Toluene:MeOH)
Table 2. UPC2 gradient for further work (B = 100% Toluene)
Figure 1. Mass chromatograms for the ions m/z 422.4203 (black), m/z 422.3305 (red), m/z 422.2362 (blue),
m/z 422.1420 (green) using four different UPC2 column chemistries with APPI
Supercritical Fluid Chromatography Coupled with Ion Mobility-Mass Spectrometry: A
Novel Approach for Profiling of Petroleum Samples
2
RESULTS AND DISCUSSION
Four different UPC2 column chemistries were evaluated
with ESI and APPI to find the best column for optimal
separation of components of an Arabian heavy oil,
maltenes fraction.
Measured accurate mass chromatograms were generated
for the ions seen at nominal m/z 422 for APPI data, and
nominal m/z 412 for ESI data. Figures 1 and 2 show the
resulting mass chromatograms.
Figure 3. Mass spectra generated at different time
points across the chromatogram showing the
distribution of masses across the chromatogram
Figure 2. Mass chromatograms for the ions m/z 412.4216
(black lower trace), m/z 412.3950 (red), m/z 412.3240
(blue), m/z 412.297 (green), m/z 412.2353 (pink), m/z
412.1288 (black upper trace) using four different UPC2
column chemistries with ESI
The Torus 1-AA column was chosen for further
investigation. Two 2.1 x 100 mm, 1.7 μm Torus 1-AA
columns were coupled together for enhanced resolution.
Figure 3 shows resulting spectra at different time points
from the gradient shown in Table 2 and two 1-AA
columns in series, using APPI with ion mobility-MS.
Clear separations were observed, with heavier
components eluting later in the acquisition. In addition,
lower mass defect ions also eluted later while higher
mass defect ions eluted earlier — this can be seen in
Figure 4, and was also observed in the column
evaluation data (Figures 1 and 2). This gives possible
insights into class or composition as hydrogen atoms
have a positive mass defect whereas nitrogen, oxygen
and sulfur atoms have negative mass defects. This
suggests that species rich in hydrogen would have higher
total mass defects, while species rich in heteroatoms, or
deficient in hydrogen, are more likely to have lower mass
defects.
Figure 4. Zoomed view of the mass spectra generated at
different time points across the chromatogram showing the
change in mass defect across the chromatogram
Supercritical Fluid Chromatography Coupled with Ion Mobility-Mass Spectrometry: A
Novel Approach for Profiling of Petroleum Samples
3
Ion mobility data were examined in DriftScope software, where the same time points as those used in
MassLynx were investigated to observe the effects of separation in both the chromatographic and ion
mobility dimensions. Figure 5 shows DriftScope processing of the same data file as shown in Figures 3 and
4. In Figure 5, chromatograms are shown in the upper images; “mobilograms”, with m/z on the x-axis and
drift time in milliseconds on the y-axis, are shown in the middle images; and corresponding mass spectra
are shown in the lower images.
Figure 5. [A] Mobilogram and mass spectrum combined across the full chromatogram; [B] Mobilogram and full mass
spectrum peak detected; [C] Time 4.0—4.5 min. selected on the chromatogram and the mobilogram and mass
spectrum simplified accordingly; [D] Peak detection of the chromatographically simplified spectrum reveals detail it
was previously hard to see.
CONCLUSION
 Supercritical fluid chromatography is easily
coupled to ion mobility-mass spectrometry
to provide complementary, orthogonal
dimensions of separation and resolution for
complex samples such as petroleum
 Separations occurred based on mass, size,
Figure 6. PetroOrg software images for hydrocarbon
radical cations showing three different time points across
the chromatogram.
By using PetroOrg software, ion mobility data can be
further processed to reveal compositional
information about the sample. Figure 6 shows an
illustration of the potential for this approach. Here
different time points were selected and processed
within PetroOrg to gain maximum specificity and
resolution. In this case we are able to observe how
the distribution and intensity of the hydrocarbon
radical cation species changes with chromatographic
separation.
©2015 Waters Corporation
chemistry, and m/z
 Viewing and interrogation of data was
made easier by DriftScope and PetroOrg
software packages
 This multidimensional approach offers
great potential for detailed studies of highly
complex heavy oil samples
References
1. Podgorski, D.C.; Corilo, Y.E.; Nyadong, L.; Lobodin,
V.V.; Robbins,W.K.; McKenna, A.M.; Marshall, A.G.;
Rodgers, R.P., Energy & Fuels 2013, 27, 1268-1276.
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Pudenzi, M.A.; Pereira, R.C.L.; Bastos, W.; Daroda,
R.J.; Eberlin, M.N., Energy & Fuels 2013, 27, 72777286.
3. Ponthus, J.; Riches, E., Int J Ion Mobil Spec 2013, 19.
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A.M.; Rodgers, R.P., Energy & Fuels 2015, DOI:
10.1021/acs.energyfuels.5b00503.
5. Barman, B.N.; Cebolla, V.L.; Membrado, L., Crit Rev
Anal Chem 2000, 30 (2-3), 75-120.
6. Yuri E. Corilo, © PetroOrg Software, Florida State
University, All rights reserved, http://
software.petroorg.com
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