Identification of Oil Spilled at Sea by High Performance Gel Permeation Chromatography Pattern Recognition

Oil pollution in the marine environment has now become a world-wide concern. Recently, in Japan, over 1,000 cases of oil pollution have been occurring every year. It is important to develop an effective identification method for spilled oils for conservation of marine environments. A new method was developed using high performance gel permeation chromatography (GPC). Chromatograms of the molecular weight distribution of oils were obtained using an ultra-violet (UV) detector. Pattern similarities between pairs of chromatograms were calculated by section areas of the chromatograms using a computer. Sixty two kinds of crude oil imported by Japan were classified by this method, and a close relationship was found between the countries of origin of the crude oils and their chromatographic patterns. Forty nine tar balls sampled from Japanese coasts were compared with the crude oils, and the origins of the tar balls were deduced. The proposed method was effective for the identification of spilled oils, and had high sensitivity and reproducibility.