Thursday, May 6, 2004 Miller Inn Miller Brewing Company 3931 West State Street Milwaukee, Wisconsin

DIRECTIONS

As soon as organic compounds are spilled into the environment, chances will start to occur to them as a result of weathering process. For example witth crude oils changes will range from evaporation and loss of light ends to extensive biodegradation and loss of many of the compounds typically used for correlating spilled oils with their original source. As a result of these weathering processes, it is often difficult to correlate the spilled oils with their suspected sources. It is essential that these correlations be made to determine who is responsible for the spill and who pays for the clean-up process. There are a number of sophisticated techniques available for this type of forensic geochemistry which can be used for correlating weathered samples with their respective source materials. In this talk specific emphasis will be directed towards the most recent technique for use in this area namely gas chromatography combined with isotope ratio mass spectrometry (GCIRMS). Examples will be presented to demonstrate that the isotopic composition of individual compounds in complex mixtures, such as crude oils, can be used to correlate them with their weathered counterparts. It is clear from the results that GCIRMS is a powerful new tool in forensic geochemistry particularly when combined with the more traditional techniques such as GC and GCMS. Other applications will be described to demonstrate that GCIRMS can also be used to determine the source of leaks from underground storage tanks and sources of gases from leaking pipelines. Variations in the isotopic composition of the MTBE added to gasolines also provides the opportunity of using GCIRMS as a means of monitoring, and determination of the source of, gasoline spills from underground storage tanks. Applications are many and varied but with this relatively new technique the ability to correlate heavily weathered samples with their unweathered counterparts has been elevated to a new level and provided forensic geochemistry with a new dimension.

Paul received his Ph.D. in organic chemistry from the University of Sydney (Australia)in 1972 and more recently his D.Sc. degree from the same University in 1998. He then spent one and a half years as a post-doctoral fellow with Professor G. Eglinton at the University of Bristol (England) undertaking research in various aspects of organic geochemistry and the application of analytical techniques such as gas chromatography-mass spectrometry to this area of research. Following this, he spent four years at the University of California, Berkeley, as a research associate, directing the organic geochemistry research group of Professor Melvin Calvin. Paul returned to Sydney in 1977 to join the CSIRO, Fuel Geoscience Unit, now part of the Division of Fossil Fuels, where he was a principal research scientist studying various aspects of petroleum geochemistry. In June 1984, Paul joined the faculty at the University of Oklahoma. The major theme of his research during the past 15 years has been directed at the application of organic chemistry to fossil fuel research. The second major area of research has been the characterization of source rocks, coals, and oil shales using microscale pyrolysis techniques combined directly with gas chromatography-mass spectrometry. More recently a large amount of his work has been concerned with environmental studies and particularly investigating the use of stable carbon isotopes as a means of monitoring and tracking pollutants in the environment. Paul's professional activities include associate editor of Chem. Geol. and chairman of the Geochemistry Division of the American Chemical Society, Dec. 1993.