Identification of Oil Slicks by Infrared Spectroscopy

This investigation evaluated the applicability of infrared spectroscopy to identifying sources of oil spills, using computer methods for matching spectra. Eighty-five different oils of all types were 'weathered' for two weeks in at least two of four weathering grids. Two of the grids were located on Narragansett Bay (one in the Bay and one onshore), and two at the University's Kingston laboratory (one inside, and one on the roof). Spectral data on approximately 900 weathered oil samples were digitized and stored in computer data files to form a library of weathered oils. These were then compared to some 300 spectra of their unweathered sources by a computer ratio method. The investigation showed that infrared spectroscopy coupled with computer analysis is a useful technique for identifying the source of spilled oil. By using artificial weathering techniques, the correct source of a spill can be identified by infrared with a high probability when samples are collected within one week of the original spill.