Photochemical transformation and degradation of petroleum residues in the marine environment

Photochemical transformation of Ekofisk Crude Oil and its high molecular weight resin/asphaltene fraction has been studied both in the laboratory and in the field. UV, IR, ESR and field desorbtion mass spectrometry have been used in conjunction with elemental analysis and pyrolysis gas chromatography to obtain results which indicate that Ekofisk crude oil and probably crude oils with a similar composition are considerably influenced by irradiation, changing both its chemical and physical characteristics.