CHEMICAL CHARACTERIZATION OF CRUDE-OIL RESIDUES FROM AN ARCTIC BEACH BY GC MS AND GC/FID/

A complete ''total oil analysis method'' suitable for monitoring chemi cal composition changes and studying the fate of 12-year-old weathered oil residues from an arctic beach is described. The characterizations not only are through analyses of individual aliphatic, aromatic, and biomarker compounds but also are through ''pattern recognition'' plots involving more than 100 important oil components and component groupi ngs. The weathered percentages of residual oil in Baffin Island oil sp ill samples are quantified using C-29 and C-30 alpha beta-hopane in th e ''fresh'' source oil as internal oil references. The values of the w eathered percentages show excellent correlation to the total solvent-e xtractable materials (TSEM), total petroleum hydrocarbons (TPH), aliph atic, aromatic, and biomarker compound analysis results. Biodegradatio n is demonstrated to have played an important role in the degradation and removal of the residual oil. Twelve years after the spill, the com position changes due to weathering progress much more slowly, and this slower rate of change will continue under these arctic conditions.