PAGE 1

Oil Analysis
Analysis of this oil sample was conducted in the Chemical Engineering laboratories at the University
REDACTED
of Tennessee Chattanooga by Dr. Soubantika Palchoudhury,
Assistant Professor, Chemical
REDACTED
Engineering and her graduate
student, Armel Boutchuen.
Experimental Method
The liquid oil sample was characterized on a Bruker Alpha fourier transform infrared spectroscope
(FTIR) equipped with attenuated total reflectance (ATR) capabilities over a wavelength range of 4004000 cm-1 at room temperature to determine the surface functional groups in the sample and thereby
identify the oil type. FTIR spectra were reported based on five consecutive runs for reliability. Motor oil
and three different varieties of commercial edible oil (e.g., Great Value vegetable oil, Publix brand
vegetable oil, and Golden Chef vegetable oil) were also characterized using the same conditions for
comparison. Finally, the FTIR spectrum of oil sample was compared with the four other commonly used
oils analyzed, literature reports, and spectral libraries available in literature to identify the oil type. 1
Results and Discussion
Figure 1.
Image of
oils
analyzed
via FTIR
for this
project.
(Left to
right) oil sample, Great Value vegetable oil (edible oil
1), Golden Chef vegetable oil (edible oil 3), Publix
vegetable oil (edible oil 2), O Reilly motor oil, and
food grade mineral oil.

Figure 1 shows the oil sample and the four other common oils characterized. The oil sample was
transparent, but had an odor. The major peaks in FTIR spectrum of the oil sample (Figure 2a) and their
attributed chemical bonds are highlighted in Table 1. Two sharp FTIR peaks observed at 2919 cm -1 and
2851 cm-1 with a shoulder at 2939 cm-1 were attributed to the CH2 aliphatic bend.2,3 The spectrum
contained a weak peak at 1651 cm-1, characteristic of C=C aromatic stretch. 3 The transmittance at 1458
cm-1 were due to contributions from the CH 2 and CH3 bending modes while methyl bending vibrations
induced the peak at 1374 cm -1.3 A broad peak was observed at 1308 cm -1 due to ester linkages and the
peak at 719 cm-1 corresponded to the aromatic C-H out-of-plane bending vibrations. 3 The peaks at 2361
cm-1 and 2340 cm-1 are due to CO2. The FTIR profile matched with literature data and spectral profiles of
petroleum based oils such as motor oil, crude oil, diesel, or kerosene. 2,4,5,6,7

Table 1. Summary of FTIR analysis for the oil sample
No.

Wavelength of major FTIR peaks (cm - Corresponding chemical bond
)

1

1January 6th, 2020

 PAGE 2

1
2
3
4
5
6

2919 and 2851; shoulder at 2939
1651
1458
1374
1308
719

CH2 aliphatic bend
C=C aromatic stretch
CH2 and CH3 bending
Methyl bending
Ester C-O bond
C-H out-of-plane bend

Figure 2. Representative FTIR plots. (a) oil sample, (b) comparative FTIR plot of the oil sample
with three different edible oils, a commercially available motor oil, and food grade mineral oil,
and (c) comparison of the oil sample with mineral and motor oil.
In the next step, a comparison of this spectrum was made with different edible oils, mineral oil,
and motor oil (Figure 2b). A strong peak was observed at 1742 cm -1, characteristic of saturated C=O
stretch of aldehydes for the edible oils.8 This characteristic peak was also present in all oils derived from

2January 6th, 2020

 PAGE 3

plant and fatty acid or triglyceride sources, based on a detailed literature review. 9,10 This peak was absent
in the FTIR spectrum of the oil sample. In addition, two prominent peaks were observed at 1162 cm -1 and
1098 cm-1 corresponding to C-O ester linkage for edible oils as compared to one ester peak for the oil
sample. The fingerprint region of the edible oils showed broad peaks from 719 cm -1 – 668 cm-1, markedly
different from the spectrum of the oil sample. Therefore, the spectrum of the oil did not match with edible
oil or hydrogenated edible oil. The data confirmed that the analyzed oil sample was not an edible oil or
ghee.
The FTIR spectrum of oil sample matched with petroleum derived oils such as mineral oil and
motor oil as shown in Figure 2c. Motor oil is not a clear liquid, unlike the provided oil sample. A closer
match was observed with mineral oil, which is also a transparent colorless liquid obtained as a by-product
of crude refining for the production of gasoline or diesel. The results strongly suggest that the oil sample
is mineral oil.
Conclusion
Our detailed analysis based on FTIR suggest that this oil sample does not belong to the class of edible oils
or oils derived from fatty acids, triglycerides, and plant sources. The FTIR profile indicate a petroleum
derived product, particularly mineral oil. Further analysis such as gas chromatography mass spectrometry,
solvent extraction, and nuclear magnetic resonance could be used to confirm these results.
References
1.
Coates, J., Interpretation of infrared spectra, A practical approach. In Encyclopedia of Analytical
Chemistry, Meyers, R. A., Ed. John Wiley & Sons Ltd.
2.
Riley, B. J.; Lennard, C.; Fuller, S.; Spikmans, V., An FTIR method for the analysis of crude
and heavy fuel oil asphaltenes to assist in oil fingerprinting. Forensic Science International 2016, 266,
555-564.
3.
Wilt, B. K.; Welch, W. T.; Rankin, J. G., Determination of asphaltenes in petroleum crude oils
by Fourier transform infrared spectroscopy. Energy & Fuels 1998, 12 (5), 1008-1012.
4.
Asemani, M.; Rabbani, A. R., Detailed FTIR spectroscopy characterization of crude oil extracted
asphaltenes: Curve resolve of overlapping bands. Journal of Petroleum Science and Engineering 2019.
5.
Fodor, G. E.; Kohl, K. B.; Mason, R. L., Analysis of gasolines by FT-IR spectroscopy.
Analytical Chemistry 1996, 68 (1), 23-30.
6.
Samanta, A.; Ojha, K.; Mandal, A., Interactions between acidic crude oil and alkali and their
effects on enhanced oil recovery. Energy & Fuels 2011, 25 (4), 1642-1649.
7.
Revathy, T.; Jayasri, M. A.; Suthindhiran, K., Biodegradation of PAHs by Burkholderia sp.
VITRSB1 Isolated from Marine Sediments. Scientifica 2015, 867586, 9 pages.
8.
Lewis, R.; McElhaney, R. N.; Pohle, W.; Mantsch, H. H., Components of the carbonyl
stretching band in the infrared-spectra of hydrated 1,2-diacylglycerolipid bilayers - a reevaluation.
Biophysical Journal 1994, 67 (6), 2367-2375.
9.
Rohman, A.; Windarsih, A.; Riyanto, S.; Sudjadi; Ahmad, S. A. S.; Rosman, A. S.; Yusoff, F.
M., Fourier transform infrared spectroscopy combined with multivariate calibrations for the
authentication of avocado oil. International Journal of Food Properties 2016, 19 (3), 680-687.
10.
Rohman, A., Infrared spectroscopy for quantitative analysis and oil parameters of olive oil and
virgin coconut oil: A review. International Journal of Food Properties 2017, 20 (7), 1447-1456.

3January 6th, 2020

 PAGE 4

Oil Analysis
Analysis of this oil sample was conducted in the Chemical Engineering laboratories at the University
REDACTED
of Tennessee Chattanooga by Dr. Soubantika Palchoudhury,
Assistant Professor, Chemical
REDACTED
Engineering and her graduate
student, Armel Boutchuen.
Experimental Method
Two liquid oil samples were characterized on a Bruker Alpha fourier transform infrared spectroscope
(FTIR) equipped with attenuated total reflectance (ATR) capabilities over a wavelength range of 4004000 cm-1 at room temperature to determine the surface functional groups in the sample and thereby
identify the oil type. FTIR spectra were reported based on five consecutive runs for reliability. Motor oil,
mineral oil, and three different varieties of commercial edible oil (e.g., Great Value vegetable oil, Publix
brand vegetable oil, and Golden Chef vegetable oil) were also characterized using the same conditions for
comparison. Finally, the FTIR spectra of oil samples were compared with the four other commonly used
oils analyzed, literature reports, and spectral libraries available in literature to identify the oil type. 1
Results and Discussion

Figure 1. Image of oils analyzed via FTIR for this
project. (Left to right) oil sample, Great Value
vegetable oil (edible oil 1), Golden Chef vegetable oil
(edible oil 3), Publix vegetable oil (edible oil 2), O
Reilly motor oil, food grade mineral oil, and oil sample
2.
Figure 1 shows two oil samples and the four other common oils characterized in our study. Both oil
samples were transparent, but had an odor. Both oil samples showed similar characteristics. The major
peaks in FTIR spectrum of the oil sample (Figure 2a) and their attributed chemical bonds are highlighted
in Table 1. Two sharp FTIR peaks observed at 2919 cm -1 and 2851 cm-1 with a shoulder at 2939 cm -1 were
attributed to the CH2 aliphatic bend.2,3 The spectrum contained a weak peak at 1651 cm -1, characteristic of
C=C aromatic stretch.3 The transmittance at 1458 cm-1 were due to contributions from the CH2 and CH3
bending modes while methyl bending vibrations induced the peak at 1374 cm -1.3 A broad peak was
observed at 1308 cm-1 due to ester linkages and the peak at 719 cm -1 corresponded to the aromatic C-H
out-of-plane bending vibrations.3 The peaks at 2361 cm-1 and 2340 cm-1 are due to CO2. The FTIR profile
matched with literature data and spectral profiles of petroleum based oils such as motor oil, crude oil,
diesel, or kerosene.2,4,5,6,7

Table 1. Summary of FTIR analysis for the oil samples
No.

Wavelength of major FTIR peaks (cm - Corresponding chemical bond
1
)

1January 31st, 2020

 PAGE 5

1
2
3
4
5
6

2919 and 2851; shoulder at 2939
1651
1458
1374
1308
719

CH2 aliphatic bend
C=C aromatic stretch
CH2 and CH3 bending
Methyl bending
Ester C-O bond
C-H out-of-plane bend

Figure 2. Representative FTIR plots. (a) oil sample, (b) comparative FTIR plot of the two oil
samples with three different edible oils, a commercially available motor oil, and food grade
mineral oil, and (c) comparison of the oil samples with mineral and motor oil.
In the next step, a comparison of this spectrum was made with different edible oils, mineral oil,
and motor oil (Figure 2b). A strong peak was observed at 1742 cm -1, characteristic of saturated C=O

2January 31st, 2020

 PAGE 6

stretch of aldehydes for the edible oils.8 This characteristic peak was also present in all oils derived from
plant and fatty acid or triglyceride sources, based on a detailed literature review. 9,10 This peak was absent
in the FTIR spectrum of the oil sample. In addition, two prominent peaks were observed at 1162 cm -1 and
1098 cm-1 corresponding to C-O ester linkage for edible oils as compared to one ester peak for the oil
sample. The fingerprint region of the edible oils showed broad peaks from 719 cm -1 – 668 cm-1, markedly
different from the spectrum of the oil samples. Therefore, the spectrum of the oil did not match with
edible oil or hydrogenated edible oil. The data confirmed that the analyzed oil sample was not an edible
oil or ghee.
The FTIR spectrum of oil sample matched with petroleum derived oils such as mineral oil and
motor oil as shown in Figure 2c. Motor oil is not a clear liquid, unlike the provided oil sample. A closer
match was observed with mineral oil, which is also a transparent colorless liquid obtained as a by-product
of crude refining for the production of gasoline or diesel. The results strongly suggest that the oil sample
is mineral oil.
Conclusion
Our detailed analysis based on FTIR suggest that this oil sample does not belong to the class of edible oils
or oils derived from fatty acids, triglycerides, and plant sources. The FTIR profile indicate a petroleum
derived product, particularly mineral oil. In addition, both oil samples showed similar FTIR profiles.
Further analysis such as gas chromatography mass spectrometry, solvent extraction, and nuclear magnetic
resonance could be used to confirm these results.
References
1.
Coates, J., Interpretation of infrared spectra, A practical approach. In Encyclopedia of Analytical
Chemistry, Meyers, R. A., Ed. John Wiley & Sons Ltd.
2.
Riley, B. J.; Lennard, C.; Fuller, S.; Spikmans, V., An FTIR method for the analysis of crude
and heavy fuel oil asphaltenes to assist in oil fingerprinting. Forensic Science International 2016, 266,
555-564.
3.
Wilt, B. K.; Welch, W. T.; Rankin, J. G., Determination of asphaltenes in petroleum crude oils
by Fourier transform infrared spectroscopy. Energy & Fuels 1998, 12 (5), 1008-1012.
4.
Asemani, M.; Rabbani, A. R., Detailed FTIR spectroscopy characterization of crude oil extracted
asphaltenes: Curve resolve of overlapping bands. Journal of Petroleum Science and Engineering 2019.
5.
Fodor, G. E.; Kohl, K. B.; Mason, R. L., Analysis of gasolines by FT-IR spectroscopy.
Analytical Chemistry 1996, 68 (1), 23-30.
6.
Samanta, A.; Ojha, K.; Mandal, A., Interactions between acidic crude oil and alkali and their
effects on enhanced oil recovery. Energy & Fuels 2011, 25 (4), 1642-1649.
7.
Revathy, T.; Jayasri, M. A.; Suthindhiran, K., Biodegradation of PAHs by Burkholderia sp.
VITRSB1 Isolated from Marine Sediments. Scientifica 2015, 867586, 9 pages.
8.
Lewis, R.; McElhaney, R. N.; Pohle, W.; Mantsch, H. H., Components of the carbonyl
stretching band in the infrared-spectra of hydrated 1,2-diacylglycerolipid bilayers - a reevaluation.
Biophysical Journal 1994, 67 (6), 2367-2375.
9.
Rohman, A.; Windarsih, A.; Riyanto, S.; Sudjadi; Ahmad, S. A. S.; Rosman, A. S.; Yusoff, F.
M., Fourier transform infrared spectroscopy combined with multivariate calibrations for the
authentication of avocado oil. International Journal of Food Properties 2016, 19 (3), 680-687.
10.
Rohman, A., Infrared spectroscopy for quantitative analysis and oil parameters of olive oil and
virgin coconut oil: A review. International Journal of Food Properties 2017, 20 (7), 1447-1456.

3January 31st, 2020