Degradation of Gasoline, Barbecue Starter Fluid, and Diesel Fuel by Microbial Action in Soil

The effects of microbial action on the chromatographic profile of automotive gasoline, barbecue starter fluid, and diesel fuel in soil have been studied. Soil samples were injected with 3 different types of petroleum products including 5 brand name automotive gasolines, barbecue starter fluid, and diesel fuel. Injected soil samples were sealed in 1 L Mason jars and subsequently analyzed after 2, 4, 7, and 14 days using a passive headspace charcoal adsorption/elution method and gas chromatography-mass spectrometry. Resulting gas chromatograms were compared to time-zero profiles and showed varying amounts of microbial degradation. The majority of the degradation occurred between 7 and 14 days, and targeted n-alkane and mono-substituted aromatic components before poly-substituted aromatic or substituted aliphatic components in all trials. Implications for fire debris analysis in forensic laboratories are discussed.