A review of experimental procedures of gas chromatography-mass spectrometry (gc-ms) and possible sources of analytical errors
Volume 1, Issue 1, December 2012, Pages: 1-9
Received: Dec. 21, 2012;
Published: Dec. 30, 2012
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Waheed Gbenga Akande, Department of Geology, Federal University of Technology, Minna, Nigeria
This paper reviews the experimental procedures of the Gas Chromatography-Mass Spectrometry (GC-MS) technique. The objectives of this study are to present a step-by-step procedure involved in the GC-MS analysis and inter-pretations of the resulting data both qualitatively and quantitatively, and to identify the possible sources of analytical errors that may be encountered by young inexperienced organic geochemists. The overall process encompasses ultrasonic solvent extraction, fractionation and GC-MS analysis itself. The qualitative and quantitative information obtained from the GC-MS interpretations when integrated together is capable of giving us an insight into the source or origin, depositional environment and level thermal maturity of the analysed sample. The possible sources of analytical errors may include contamination, measurement errors, mechanical/instrumental errors, fractionation errors, and loading errors on the GC. Analytical geochemists must therefore be aware of these errors among others in order to minimise them to the reasonable level. It is recommended that, if weak signals result from the GC-MS analysis of a fraction, such a fraction should be prepared in higher concentration and re-run using selected ion monitoring (SIM) mode so as to enhance signal to noise ratio, and that the GC-MS data should always be interpreted with GC-MS softwares with biomarkers definitions in order to obtain more reliable and robust interpretations.
Waheed Gbenga Akande,
A review of experimental procedures of gas chromatography-mass spectrometry (gc-ms) and possible sources of analytical errors, Earth Sciences.
Vol. 1, No. 1,
2012, pp. 1-9.
W. G. Dow, "Kerogen Studies and Geological Interpreta-tions. Journal of Geochemical Exploration", vol. 7, pp. 77-79, 1977.
J. A. Williams, "Characterization of oil types in Wiliston Basin", American Association Petroleum Geologists Bul-letin, vol. 58, pp. 1243-1252, 1974.
D. H. Welte, H. W. Hagemann, A. Hollerbach, and D. Leythanuser, "Correlation between petroleum and source rocks", Proceedings 9th World Petroleum Congress, vol. 2: pp. 179-191, 1976.
W. G. Akande, "Mesozoic Organic-rich Rocks of Southern England", Unpublished M.Sc. Dissertation. Imperial College, London, 2011.
Imperial Lab Manual, Imperial College Petrophys-ics/Organic Laboratory Manual Guide for 2009/2000 academic session, 2009.
NIGOGA, The Norwegian Industry Guide to Organic Geochemical Analyses, Edition 4.0. Published by Norsk Hydro Statoil Geolab Nor SINTEF Petroleum Research Norwegian Petroleum Directorate, 2000.
B. M. Didyk, B. R. T. Simoneit, S. C. Brassell, and G. Eglinton, "Organic geochemical indicators of paleoenvi-ronmental conditions of sedimentation", Nature, vol. 272, pp. 216 – 222, 1978.
G. W. Lijmbach, "On the Origin of Petroleum, in Pro-ceedings of the 9th World Petroleum Congress", vol. 2. London: Applied Science Publishers, 1975, pp. 57 – 369.
J. Connan, and A. M. Cassau, "Properties of gas petro-leum liquids derived from terrestrial kerogen at various maturation levels", Geochim. Cosmochim.Acta, vol. 44, pp. 10 – 23, 1980.
K. E. Peters, T. H. Fraser, W. Amris, B. Rustanto, and E. Hermanto, "Geochemistry of crude oils from eastern In-donesia", American Association of Petroleum Geologists Bulletin, vol. 83, pp. 1927 – 1942, 1999.
J. M. Moldowan, W. K. Seifert, and E. J. Gallegos, "Rela-tionship between petroleum composition and depositional environment of petroleum source rocks", American Asso-ciation of Petroleum Geologists Bulletin, vol. 69, pp. 1255-1268, 1985.
K. E. Peters, and J. M. Moldowan, "Effects of source, thermal maturity, and biodegradationon the distribution and is omerisation of homohopanes in petroleum", Organic Geochemistry, vol. 17, pp. 47-62, 1991.
K. E. Peters, and J. M. Moldowan, The Biomarker Guide: Interpreting Molecular Fossils and Ancient Sediments. Prentice Hall: Eaglewood Cliffs, 1993, pp. 1-363.
P. E. Summons, and T. G. Powell, "Identification of aryli-soprenoids in source rock and crude oils: Biological markers for the green sulphur bacteria", Geochimica et Cosmochimica Acta, vol.51, pp. 557-566, 1987.