Molecular Fingerprinting of Gasoline by a Modified EPA 8260 Gas Chromatography-Mass Spectrometry Method

Automotive gasoline is a common petroleum product found at contaminated terrestrial sites. The need to recognize and distinguish different types of gasoline(s) that may be present at a contaminated site and the need to determine the relative proportion of inputs from different sources, are often critical components of environmental 'forensic' investigations. Historically, identification and differentiation of automotive gasolines (particularly when weathered) has been hampered by analytical limitations of existing methods, notably US EPA Method 8260. In this article, we describe a modified EPA Method 8260 that is suitable for environmental investigations involving gasoline (and other light petroleum products). In the modified EPA 8260 method, 109 analytes that can occur in automotive gasoline are quantified in nonaqueous liquid samples (NAPL), water, and soil matrices. The accuracy and precision of the method is demonstrated through comparative analysis using several NIST SRM gasoline standards and replicate analyses.