title: Characterization, weathering, and application of sesquiterpanes to source identification of spilled lighter petroleum products.
abstract: Biomarkers have become increasingly important for identifying the source of spilled oil, due to their specificity and high resistance to biodegradation. The biomarkers most commonly used in forensic investigations are the high molecular weight (MW) tri- and pentacyclic terpanes and steranes. For lighter petroleum products such as jet fuels and diesels, the refining processes remove most high MW biomarkers from the original crude oil feedstock. The smaller bicyclic sesquiterpanes, however, are concentrated in these products. Sesquiterpanes are ubiquitous components of crude oils and ancient sediments. Examination of GC-MS chromatograms of these bicyclic biomarkers using their characteristic fragment ions (m/z 123, 179, 193, and 207) provides a highly diagnostic means for identifying spilled oil, particularly for lighter refined product samples that are difficult to identify by current techniques. In this work, sesquiterpanes in crude oils and petroleum products are identified and characterized, distributions of sesquiterpanes in oils and refined products are compared, the effects of evaporative weathering on sesquiterpane distributions are examined, and a methodology using diagnostic indices of sesquiterpanes is developed for oil correlation and differentiation. Finally, two case studies are presented to illustrate the unique utility of sesquiterpanes for fingerprinting and identifying unknown diesel spills.
authors.affiliation: Emergencies Science and Technology Division, Environmental Technology Centre, Environment Canada, Ottawa, Ontario, Canada K1A 0H3. zhendi.wang@ec.gc.ca
authors.forename: Zhendi
authors.initials: Z
authors.lastname: Wang
authors.forename: Chun
authors.initials: C
authors.lastname: Yang
authors.forename: Merv
authors.initials: M
authors.lastname: Fingas
authors.forename: Bruce
authors.initials: B
authors.lastname: Hollebone
authors.forename: Xianzhi
authors.initials: X
authors.lastname: Peng
authors.forename: Asger B
authors.initials: AB
authors.lastname: Hansen
authors.forename: Jan H
authors.initials: JH
authors.lastname: Christensen
mesh_terms: D002849:Chromatography, Gas; D004785:Environmental Pollutants / Q000032:analysis*; D005618:Fresh Water; D013058:Mass Spectrometry; D010578:Petroleum / Q000032:analysis*; D012623:Seawater; D014874:Water Pollutants, Chemical
chemical_list: D004785:Environmental Pollutants; D010578:Petroleum; D014874:Water Pollutants, Chemical