Underground Fuel Spills, Source Identification
Environment: Water and Waste
Published Online: 15 SEP 2006
Copyright © 2000 John Wiley & Sons, Ltd. All rights reserved.
Encyclopedia of Analytical Chemistry
How to Cite
Lavine, B. K., Moores, A. and Ritter, J. 2006. Underground Fuel Spills, Source Identification. Encyclopedia of Analytical Chemistry. .
- Published Online: 15 SEP 2006
Water samples from underground wells or aquifers contaminated by middle distillate fuels exist in one of two forms. Either the water sample collected from the well shows a layer of floating fuel, or the sample contains the dissolved hydrocarbons from the leaking fuel. In the worst case scenario, that of a floating fuel, the fuel layer is collected and analyzed by gas chromatography (GC). The GC profile of the fuel layer is then compared with the GC profile of the different candidate fuels to determine the fuel type of the leaking material. Usually, the gas chromatograms are compared visually, in order to obtain the best match. However, this approach to data analysis is subjective and is not always persuasive in a court of law. Visual analysis of gas chromatograms also has the drawback that it cannot take into account the influence of weathering on the overall GC profile of the fuel.
Pattern recognition (PR) methods offer a better approach to the problem of matching the gas chromatograms of jet fuels because these methods involve less subjectivity in the interpretation of the data. PR methods can identify fingerprint patterns in GC data characteristic of fuel type, even if the fuel samples have been subjected to a variety of conditions. Hence, discriminants can be developed that are relatively insensitive to the changes in the overall GC profile data of the original fuel due to contamination, analytical error, or weathering.