Use of stable carbon isotopes and multivariate statistics to source-apportion fuel hydrocarbons

Differences in hydrocarbon samples were assessed using compound-specific isotope analysis (CSIA). Samples from on-water spills and fuel tanks from possible sources (moored ships) were taken from the Norfolk Navy Base in Norfolk, VA (USA) and volatile organic compound (VOC) samples were taken from a multiple leaking underground fuel tank site in Hazleton, PA (USA). Individual compound stable carbon isotope ratios were measured and the data subjected to several multivariate statistical tests to determine similarity between sample hydrocarbon source(s). Multiple analysis of variance, principal components analysis and hierarchical clustering showed similarities between discreet samples at both sites and in the case of the Norfolk samples confirmed a shipboard leak. CSIA coupled with multivariate statistics was found to be a useful tool for source-apportioning hydrocarbons.