Source Identification of Oil Spills Based on the Isotopic Composition of Individual Components in Weathered Oil Samples
Correlation of crude oils and refined hydrocarbon products spilled in the environment with their respective sources is commonly undertaken using techniques such as gas chro matography (GC) or gas chromatography/mass spectrometry (GC/MS) or bulk parameters such as the isotopic composition of the aliphatic or aromatic fractions. Under certain circumstances extensive weathering of the samples, through evaporation, water-washing, or biodegradation, may make such correlations extremely difficult and the results somewhat tenuous. Results are presented in this paper from an investigation to study the use of gas chromatography/isotope ratio mass spectrometry (GC/IRMS) as a complimentary correlation technique to GC and GC/MS, particularly for samples that have undergone extensive weathering. In the study, a variety of oils and refined hydrocarbon products, weathered both artificially and naturally, were analyzed by GC, GC/MS and GC/IRMS. In cases where samples have lost their more volatile n-alkanes as a result of...