The use of hydrophobic pads to recover ignitable liquids from water

Significant amounts of water are used to extinguish fires, and finding evidence of ignitable liquid residue can be challenging for investigators. Hydrophobic pads have been designed to collect oil-based products from the surface of water and preferentially absorb non-polar compounds while repelling water. In this study hydrophobic pads are used to collect various classifications of ignitable liquids from the surface of water for analysis using passive headspace concentration and GC/MS analysis. Hydrophobic pads were found to be effective in collecting ignitable liquids containing hydrocarbons greater than C8, classifications medium and heavy petroleum distillates, from 10 microliters of ignitable liquids added to the surface of 100 milliliters of water. Gasoline and 50% evaporated gasoline were also recovered using the hydrophobic pads with 25 microliters of sample.