Photochemistry of petroleum: I. Systematic study of a brazilian intermediate crude oil

The photochemical weathering of a crude Brazilian petroleum as a film over sea-water by sunlight has been studied using a combination of analytical tools including elemental analysis, GC, UV-VIS, IR, Fluorescence, and NMR. Fluorescence intensity decreased rapidly upon irradiation, whereas only slight weathering could be observed by GC and IR even after 100 h of exposure to full tropical sunlight. The other methods used did not reveal observable changes in petroleum composition.