Stable carbon isotopic characterization of hydrocarbons in contaminated soils

摘要: Effective management of risks at sites featuring refractory hydrocarbon wastes is often constrained by the limitations conventional analytical methodologies. Stable carbon isotope analysis was therefore evaluated as an alternative means characterizing composition, source and weathering contaminants. Bulk {delta}{sup 13}C selected heavy oils (boiling range 50 to 500 C) varying component class distribution decreased from {minus}28.9 {minus}27.4{per_thousand} oil saturate content (from 70.6 31.7%{sup w}/w) polar/asphaltene increased 7.4 50.5%{sup w}/w). Class up 2.5{per_thousand} follows: saturates (ca. {minus}29{per_thousand}) < aromatics ({approx} whole oil) polars asphaltenes {minus}26{per_thousand}). Thus, prevalence either or polar/asphaltenes can be inferred unusually low (for saturates) high polar/asphaltenes) 13}C. Plots vs. confirmed this relationship, returning linear correlation coefficients (r{sup 2}) 0.93 0.99, respectively. Characteristic isotopic fingerprints oils, crude acid tar may also provide a valuable differentiating between possible terms. Unweathered, 25%, 50% 75% weathered reference were analyzed compound specific (CSIA). n-Alkane (C{sub 13}-C{sub 23})more » 1--2{per_thousand} lower in samples (e.g., C{sub 15} = {minus}27.14{per_thousand} (fresh), {minus}26.86{per_thousand} {minus}25.36{per_thousand} 50%, undetected 75%). CSIA established biomarkers, detected GC/MS, facilitated creation index for quantifying extent undergone. Subsequent work investigating effects biotransformation on underway.« less