Young, D.R., R.J. Ozretich, and D.B. Chadwick. 2002. Small volume sampling and GC/MS analysis for PAH concentrations in water above contaminated sediments. Chapter 15 in R.L. Lipnick, R.P. Mason, M.L. Phillips and C.U. Pittman, editors. Chemicals in the Environment: Fate, Impacts, and Remediation. American Chemical Society Symposium Series 806, Oxford University Press.
A procedure for measuring very low concentrations of potentially toxic petroleum residues in small water samples has been developed by EPA’s Office of Research and Development. Many of these compounds, called Polycyclic Aromatic Hydrocarbons or PAHs, are included in EPA’s list of Priority Pollutants. Only one-half of a liter of water is sampled in this method, enabling its application to specialized equipment such as an instrument placed on the sea floor to determine rates of release for sediment contaminants of concern. The analytical technique, which includes the use of a mass spectrometer, is quite sensitive. Despite the small volume of sample collected, PAH concentrations below one-trillioneth of a gram per liter (1 nanogram/L) can be measured. This technique was tested at the U.S. Naval Shipyard in Puget Sound, WA, where relatively high concentrations of PAHs were measured in the surface sediments. Over sampling periods of 1 -2 days, clearly-discernable rates of loss from these sediments to the overlying water were observed for several toxic PAH compounds. However, the water concentrations measured were at least one thousand times less than those reported to have any effect on marine organisms.