Stacy K. Seeley, Steven V. Bandurski, Robert G. Brown, James D. McCurry and John V. Seeley

 Platform Presentation

 Approximately ten years have passed since the first generation of risk-based petroleum methods was developed and put into production in the environmental laboratory. However, the precise amounts of the several different solvents needed, in addition to variables affecting the fractionation media, often result in “breakthrough” of target compounds into the wrong fraction(s) and/or contamination of the final extract(s). Advances in gas chromatographic and flow control technologies can now be used to replace the tedious sample preparation techniques previously required to obtain the separate sample extracts (“fractions”) used for site characterization/assessment. 

 Soil/wastewater samples are extracted using methylene chloride.  Extracts are dried with sodium sulfate, concentrated and treated with silica gel to remove polar, non-petroleum related compounds.  The final extract is then analyzed using a two-dimensional gas chromatograph (2-D GC; GC x GC) designed to separate the aliphatic and aromatic species present in the extract using flame ionization detection (FID).

 This new approach meets the original intent of the Massachusetts state and TPH Working Group methods to measure and quantitate collective aliphatic and aromatic hydrocarbon concentrations, as well as target polynuclear aromatic hydrocarbons (PAHs).