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A Comparison of the Methods of Medium Resolution Selected Ion Recording and Multiple Reaction Monitoring When Applied to the Analysis of Steranes and Triterpenes in Crude Oil Extracts Pages: 25 Published: Jan 1989
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View License Agreement Oil correlation studies and assessments of the environment of deposition of source rocks and of the maturation, migration, and biodegradation of crude oils are commonly based upon the distribution of “biological marker” compounds within the oil or source rock extract. The measurement of these compounds involves the use of combined capillary column gas chromatography with mass spectrometry. However, the compounds are usually present at low levels and so selected ion recording techniques are preferred. Comparisons are made of two methods for increasing the selectivity of the mass spectrometer beyond that available when using nominal mass resolution, such as that available with quadrupole instruments. These methods are, increasing the mass spectrometer resolving power to, say 2 to 3000, and secondly to monitor fragments formed in the first field free region of a double-focusing instrument. The second method generally yields data that are easier to interpret and are less confused by interferences. Moreover, the sensitivity is adequate to obtain results using whole oils and total source rock extracts without prior sample cleanup and concentration. | ||
