DISTRIBUTION OF AROMATIC HYDROCARBONS IN SEDIMENTS FROM SELECTED ATLANTIC, GULF OF MEXICO, AND PACIFIC OUTER CONTINENTAL SHELF AREAS.

Approximately one hundred near-surface sediments from selected Atlantic, Gulf of Mexico, and Southern California OCS areas were analyzed. Hydrocarbon components were extracted by reflux with hexane and benzene. The aromatic components were isolated by silica gel absorption chromatography and were analyzed by high-resolution gas chromatography and GC-MS methods. Total aromatics ranged from 9. 0 to 1080 ng/g dry weight of sediment. Aliphatics were present from 3 to 5 times higher in concentration than aromatics. Pristane:phytane ratios were generally 1:6 in samples that were rich in the aromatic components. In terms of relative abundance, two-ring PAHs were more abundant than three rings, which were more abundant than four rings.