FRACTIONATION OF A LIGHT CRUDE-OIL AND IDENTIFICATION AND QUANTITATION OF ALIPHATIC, AROMATIC, AND BIOMARKER COMPOUNDS BY GC-FID AND GC-MS .2.

Two hundred eighty-one compounds (102 aliphatic, 126 aromatic, and 53 biomarker hydrocarbons) in Alberta Sweet Mix Blend (ASMB) oil are identified and characterized. Structural identification is based on mass data, comparison of GC retention data with reference standards, and calculation of retention index (RI) values and subsequent verification of the values by comparison with literature RI values. The quantitation of the important components in oil, including individual n-alkanes (n-C8 to n-C40), selected isoprenoids, total petroleum hydrocarbons, target polycyclic aromatic hydrocarbons (PAHs), alkyl PAH homologues, and biomarker compounds, is accomplished using an internal standard method. The n-alkane distribution shows that n-C8 to n-C17 are present in a higher concentration than other n-alkanes. The dominant aromatics are alkyl homologues of benzene, naphthalene, and phenanthrene with some contribution from sulfur-containing dibenzothiophenes. The most notable feature about hopane composition is the greater abundance of pentacyclic C30 and C2g α, β- hopane compared with a relatively low quantity of tricyclic and tetracyclic hopanes. The dominance of C27 and C29 steranes is apparent with the distribution of diasteranes being significant. Extensive qualitative and quantitative chemical composition information about ASMB oil is extremely useful because ASMB oil is often used in many laboratories in Canada and other countries as a reference material for comparison of analytical methods and results. This information will be used as a basis for further studies on oil weathering and biodegradation. © 1994, Oxford University Press. All rights reserved.