Volatile organic compounds in Gulf of Mexico sediments.

Volatile organic compounds (VOC), concentrations and compositions were documented for estuarine, coastal, shelf, slope, and deep water sediments from the Gulf of Mexico. VOC were measured (detection limit >0.01 ppb) using a closed-loop stripping apparatus with gas chromatography (GC) and flame ionization, flame photometric, and mass spectrometric detectors. The five primary sources of Gulf of Mexico sediment VOC are: 1) planktonic and benthic fauna and flora; 2) terrestrial material from riverine and atmospheric deposition; 3) anthropogenic inputs; 4) upward migration of hydrocarbons; and 5) transport by bottom currents or slumping. Initially sediment VOC concentrations are controlled aby the amount and type of VOC sources. VOC are then modified and redistributed by biological, geological, physical and chemical processes. GC patterns of VOC have recognizable fingerprints that are source specific. Houston Ship Channel and Galveston Bay sediment VOC are sourced from biological debris, petroleum (shipping activities), automobile exhaust, and industrial complexes. Detected organo-sulfur compounds include alkylated sulfides, thiophane, alkylated thiophenes, and benzothiophenes.