PETROLEOMICS
M A R K P. B A R R OW
OVERVIEW
Mass spectrometry, with focus upon FTICR MS
Introduction to petroleum, famous names, and the supply of petroleum
Petroleomics
Data analysis and visualization
Athabasca oil sands
Case study: comparing sources of water from the Athabasca region
Summary
MASS SPECTROMETRY
MASS SPECTROMETRY
Must vaporize and ionize the sample
Measure mass-to-charge ratio (“m/z”) of ions, not mass directly
From the data, can determine composition of an ion
(e.g. H2O, CO2, C6H5OH, etc.)
Can analyze pure compounds or mixtures
J. J. THOMSON, 1906
F. W. ASTON, 1922
W. PAUL, 1989
H. G. DEHMELT, 1989
J. B. FENN, 2002
K. TANAKA, 2002
MASS SPECTROMETRY AND THE NOBEL PRIZE
COMPONENTS OF A MASS SPECTROMETER
ION SOURCE
ANALYZER
DETECTION
DATA SYSTEM
Vaporize and
ionize sample
Method for m/z
determination
Detect ions
Mass spectrum
VARIETIES OF ANALYZER
Magnetic sector
Time-of-flight (TOF)
Quadrupole
Ion trap
Fourier transform ion cyclotron resonance (FTICR)
Orbitrap
FOURIER TRANSFORM ION CYCLOTRON
RESONANCE MASS SPECTROMETRY
FOURIER TRANSFORM ION CYCLOTRON
RESONANCE MASS SPECTROMETRY
Published in 1974 by Melvin B. Comisarow and Alan G. Marshall
Typically use superconducting magnets
Ions orbit inside FTICR cell in presence of magnetic field; frequency of
orbit inversely proportional to m/z
Expensive and require user expertise
Advantages include ultra-high resolving power and mass accuracy
No other variety of mass spectrometer can provide the same level of
performance
Well-suited to the study of complex mixtures
RESOLVING POWER
“...may be characterized by giving the
peak width... for at least two points
on the peak, specifically at fifty
percent and at five percent of the
maximum peak height.” (IUPAC Gold
Book)
Allows user to observe closely
spaced peaks
Higher values (narrower peaks) are
better
Examples:
≈10,000 (FWHM) for TOF
≈500,000+ (FWHM) for FTICR
Resolving power m
6m
MASS ERRORS
Figure of merit associated with
measurement; measured in ppm
Better mass accuracy allows user to
have higher confidence in assignment
Lower values are better
Examples:
TOF typically 3-5 ppm
FTICR typically ≤ 1 ppm
EXAMPLES OF EFFECT OF TRANSIENT LENGTH UPON RESOLVING POWER
INTRODUCTION TO PETROLEUM
PETROLEUM
Formed by compression and heating of
plant and animal remains over millions of
years; finite supply
Highly complex mixtures, thousands of
components
Each species will contain C and H atoms,
with possible N, O, and S atoms (i.e.
CcHhNnOoSs)
“Petroleomics”
Characterization of oils and their products;
can fingerprint oils, study corrosion,
investigate weathering and biodegradation,
and monitor man-made effects, amongst
other objectives
USES OF CRUDE OIL
Fuels
Lubricants
Heating oil
Solvents
Plastics
Detergent
Asphalt
Fertilizers
Synthetic rubber
Pesticides
Synthetic fibers
Food additives
Dyes
Medicine
Waxes
FAMOUS NAMES ASSOCIATED
WITH PETROLEUM
ALFRED NOBEL
JOHN D. ROCKEFELLER
SUPPLY OF PETROLEUM
Referenced in US Department of Energy report:
“Strategic Significance of America’s Oil Shale Resource:
Volume I Assessment of Strategic Issues,” March 2004
“Presently, world oil reserves are being depleted
three times as fast as they are being discovered.”
NATURE, 481, 2012, PP. 433 - 435
(JANUARY 26TH, 2012)
PETROLEOMICS
FTICR AND PETROLEUM
Examples include studies of:
Whole crude oils
Asphaltenes
Fuels
Deposit formation
Effects of different processes (e.g. biodegradation, weathering, etc.)
Corrosion (e.g. naphthenic acids)
NAPHTHENIC ACIDS
Defined as carboxylic acids which include one or more saturated ring
structures, but the term has become more loosely used
CnH2n+ZO2, where Z is the “hydrogen deficiency” and is a negative, even
integer
Crude oil typically contains naphthenic acids in quantities of up to 4% by
weight
Toxic towards aquatic wildlife and known to cause corrosion
“Total acid number” (TAN) defined as the mass of potassium hydroxide
(in milligrams) required to neutralize one gram of crude oil
TAN no longer seen as a reliable indicator of naphthenic acid content
CcH(2c+Z)O2
DOUBLE BOND EQUIVALENTS (DBE)
(SUM OF RINGS PLUS DOUBLE BONDS)
“NAPHTHENIC ACIDS” - EXAMPLE STRUCTURES
DATA ANALYSIS AND VISUALIZATION
OR: “DISSECTING A CRUDE OIL”
12 T FTICR DATA FOR A CRUDE OIL
12 T FTICR DATA FOR A CRUDE OIL
~m/z 374 - 394
12 T FTICR DATA FOR A CRUDE OIL
~m/z 384.0 - 384.5
384.00
384.50
12 T FTICR DATA FOR A CRUDE OIL
RESOLVING POWER AT M/Z 299
CATEGORIZING IONS FROM A CRUDE OIL
Once all the molecular formulae are known, typically categorize using:
Heteroatom class
Examples: “CH” (hydrocarbon, no heteroatoms), S1, N1, etc.
Double bond equivalents (DBE) or “hydrogen deficiency” (Z)
Formation of rings and double bonds when pairs of hydrogen atoms
are lost
Carbon number
Useful for overall size of molecule and for comparing alkyl chain
lengths when DBE is constant
KENDRICK MASS DEFECT
Based upon work of Kendrick in 1963 (Anal. Chem., 1963, 35, pp. 2146-2154)
and the work of Hsu, Qian, and Chen (Anal. Chim. Acta, 1992, 264, pp. 79-89)
Principle is to normalize mass scale to CH2 instead of 12C
Kendrick mass is given by:
Then determine the Kendrick mass defect (sometimes referred to as KMD):
EXAMPLE OF CALCULATING KENDRICK
MASS DEFECT
Example: C23H43O2IUPAC mass: 351.32685
Kendrick mass = 351.32685 x (14.00000/14.01565) = 350.93456
Nominal Kendrick mass = 351
Kendrick mass defect = 351 - 350.93456 = 0.06544
CHANGE IN RINGS OR DOUBLE BONDS
ADDING CH2
PLOT OF KENDRICK MASS DEFECT VS. NOMINAL KENDRICK MASS
DOUBLE BOND EQUIVALENTS (DBE)
Double bond equivalents (DBE) is a measure of double bonds plus rings
Where n is the number of atoms and v is the valence, the number of double
bond equivalents is given by:
For CcHhNnOoSs, this can be expressed as:
Note: number of oxygen and (divalent) sulfur atoms does not directly affect the
DBE (e.g. O2 and O4 species may overlap)
O2 CLASS
DOUBLE BOND EQUIVALENTS VS. CARBON NUMBER
O2 class
LINE PLOT
HEAT MAP
EXAMPLE:
CnH2n-6O2
n=15
C15H24O2
HEAT MAP
CcH(2c+Z)Ox
CcH(2c+Z)OxS
CcH(2c+Z)N
CcH(2c+Z)S
COMPOUND CLASSES
CcH(2c+Z)NOx
12 T APPI FTICR DATA FOR A CRUDE OIL
ATHABASCA OIL SANDS
BILLION BARRELS EXPORTED TO USA (2011)
900,000
675,000
450,000
225,000
da
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la
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ria
ge
Ni
Ira
q
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Co
lo
m
la
go
An
il
az
Br
ia
ss
Ru
ua
do
r
Ec
it
wa
Ku
Al
ge
ria
0
SOURCE: ENERGY INFORMATION ADMINISTRATION
TOTAL OIL RESERVES IN 2011 (BILLION BARRELS)
Venezuela
Saudi Arabia
Canada
Iran
Iraq
Kuwait
UAE
Russia
Libya
Conventional oil
Undeveloped oil sands
Developed oil sands
Nigeria
0
SOURCE: BP
75
150
225
300
Athabasca oil sands become economically viable
ATHABASCA OIL SANDS
Oil sands contain clay, sand, water, and bitumen
Alkaline hot water extraction process used to separate the bitumen,
which can be upgraded to create synthetic oil
Approximately three barrels of water needed to create one barrel of oil
from oil sands
Water can be recycled and is stored in tailings ponds
Need to study potential environmental impact of components from oil
sands process water (OSPW)
“Naphthenic acids” (CcH2c+ZO2) are particularly studied
known to be corrosive and also toxic towards aquatic wildlife
amenable to negative-ion electrospray ionization
NATURE, 468, 2010, PP. 499 - 501
(NOVEMBER 25TH, 2010)
CHARACTERIZATION OF OIL SANDS
PROCESS WATER (OSPW)
12 T SUPERCONDUCTING
MAGNET
ION OPTICS
ION SOURCE
SYRINGE PUMP
POSITIVE-ION 12 T APPI FTICR DATA: OIL SANDS PROCESS WATER (OSPW)
EXAMPLE: OIL SANDS PROCESS WATER BY GC
NEED FOR HIGH RESOLVING POWER
EXAMPLE: OIL SANDS PROCESS WATER BY FTICR MS
NEED FOR HIGH RESOLVING POWER
RESOLVING POWER ~30,000
NEED FOR HIGH RESOLVING POWER
RESOLVING POWER ~500,000
NEED FOR HIGH RESOLVING POWER
THEORETICAL PATTERN FOR C15H25O3S+
APPLICATION: COMPARING PROFILES
OVERBURDEN
OIL SANDS DEPOSIT
RIVER BANK IN ATHABASCA REGION
NEGATIVE-ION ESI FTICR DATA: ATHABASCA RIVER WATER
~m/z 311.05 - 311.19
NEGATIVE-ION ESI FTICR DATA: ATHABASCA RIVER WATER
RMS ERROR: 0.18 PPM
ONE ELECTRON:
~0.000548 DA
0.2 PPM:
DIFFERENCE BETWEEN
300.00000 DA AND
300.00006 DA
EXAMPLE OF MASS ERRORS
~
NEGATIVE-ION ESI FTICR DATA: GREGOIRE LAKE WATER
NEGATIVE-ION ESI FTICR DATA: “OIL COMPANY A”
NEGATIVE-ION ESI FTICR DATA: “OIL COMPANY B”
COMPARING OIL COMPANY A AND OIL COMPANY B
COMPARING OIL COMPANY A AND OIL COMPANY B
17.5
16.5
4.E+09
O4 CLASS
15.5
14.5
3.E+09
12.5
11.5
Intensity
Double bond equivalents
13.5
10.5
9.5
2.E+09
8.5
7.5
1.E+09
6.5
5.5
4.5
3.5
1.E+07
2.5
1.5
32
30
28
26
24
22
20
18
16
14
12
10
8
0.5
Carbon number
DOUBLE BOND EQUIVALENTS: OIL COMPANY A
17.5
16.5
5.E+09
O4 CLASS
15.5
14.5
4.E+09
12.5
11.5
Intensity
Double bond equivalents
13.5
10.5
9.5
3.E+09
8.5
7.5
1.E+09
6.5
5.5
4.5
3.5
1.E+07
2.5
1.5
32
30
28
26
24
22
20
18
16
14
12
10
8
0.5
Carbon number
DOUBLE BOND EQUIVALENTS: OIL COMPANY B
17.5
16.5
7.E+08
O4 CLASS
15.5
14.5
5.E+08
12.5
11.5
Intensity
Double bond equivalents
13.5
10.5
9.5
4.E+08
8.5
7.5
2.E+08
6.5
5.5
4.5
3.5
1.E+07
2.5
1.5
32
30
28
26
24
22
20
18
16
14
12
10
8
0.5
Carbon number
DOUBLE BOND EQUIVALENTS: GREGOIRE LAKE
OIL COMPANY A
NATURAL
OIL COMPANY B
PRINCIPAL COMPONENT ANALYSIS
SUMMARY
Dependence upon petroleum is not going to end soon
Need to better understand composition/quality of oil and to study effects
of various processes
FTICR offers ultra-high mass accuracy and resolving power
Can resolve and assign the thousands of components present in complex
mixtures
Establish profiles for samples, which can be compared
FTICR mass spectrometry is proving invaluable for studying potential
environmental impact of the oil sands industry