Identification and differentiation of light-and middle-distillate petroleum for nrda using chemical forensics

Abstract

The need for identification, delineation, and differentiation of petroleum-derived contaminants in support of NRDA investigations of chronic or catastrophic release of petroleum is paramount for the equitable settlement of damages related to the incidents. Significant advances have been made over the last decade with regard to these issues for crude oil and heavy residual fuels, but less emphasis has been place on the forensic chemistry of light- and middle-distillates. Historically, identification and differentiation among similar light distillates by standard EPA methods have been hampered by analytical limitations. In this paper we suggest analysis of light distillate products begin with a Chromatographic profile obtained using a modified EPA 8015 GC/FID. Subsequently, the detailed chemical composition of the distillate products is accomplished via a modified version of EPA Method 8260, examining a targeted list of diagnostic petroleum compounds in the C 5 to C 12 range that represent five important categories of hydrocarbons: Paraffins, Isoparaffins, Aromatics, Naphthenes, and Olefins. Detailed analysis of over 50 2-6 ring PAH and related heteroatomics from a modified EPA 8270 GC/MS analysis can be used to compliment the data set. The analysis of the full suite of hydrocarbons across a broad molecular weight range provides much of the information necessary to identify and distinguish among light and middle-distillate products.