title: Chemical characterization of naturally weathered oil residues in the sediment from Yellow River Delta, China.
abstract: With its close proximity to Shengli Oilfield, China's second largest oilfield, the Yellow River Delta is at high risk for crude oil contamination. The massive oil discharge in oilfield may offer a chance for a natural experiment to investigate compositional changes of oil residues and study the stability of source- and weathering-dependent molecular parameters in oil residues after spills. The results demonstrate that the conventional diagnostic ratios, such as C2920S/(20S+20R), C29/C30H, C30βα/αβ, C3122S/(22S+22R), C2-DBTs/C2-PHENs, C3-DBTs/C3-PHENs, DBT/MCHRY, CHRY/PHENs, are also valid for oil source identification even after extensive weathering of spilled oils in terrestrial environment, although some exceptions were encountered for extensively weathered sample. Moreover, the ratios of selected specific biomarkers (the oleanane index, the gammacerane index) have been developed and assessed as source indicators. Finally, we find that some maturity parameters based on alkyl naphthalenes and methyl phenanthrenes in petroleum geochemistry, such as the methylnaphthalene ratios (TMNr, TeMNr, PMNr), the methylphenanthrene ratios (MPI-1, MPDF), can be applied for the source identification and correlation at their lightly to moderately weathered stage.
authors.affiliation: Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China. wangchy6111@163.com
authors.forename: Chuanyuan
authors.initials: C
authors.lastname: Wang
authors.forename: Jianguo
authors.initials: J
authors.lastname: Du
authors.forename: Xuelu
authors.initials: X
authors.lastname: Gao
authors.forename: Yi
authors.initials: Y
authors.lastname: Duan
authors.forename: Yanqing
authors.initials: Y
authors.lastname: Sheng
mesh_terms: D000473:Alkanes / Q000032:analysis; D015415:Biomarkers / Q000032:analysis; D005591:Chemical Fractionation; D002681:China; D002849:Chromatography, Gas; D004784:Environmental Monitoring / Q000706:statistics & numerical data*; D004785:Environmental Pollutants / Q000032:analysis*; D019015:Geologic Sediments / Q000032:analysis*; D009792:Oceans and Seas; D010578:Petroleum / Q000032:analysis*; D059392:Petroleum Pollution / Q000032:analysis*; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis; D045483:Rivers
chemical_list: D000473:Alkanes; D015415:Biomarkers; D004785:Environmental Pollutants; D010578:Petroleum; D011084:Polycyclic Aromatic Hydrocarbons