Hegg did the study with James Ehleringer, a distinguished professor of biology at the University of Utah, and Helen Kreuzer-Martin, a University of Utah research assistant professor of biology and a staff scientist at Pacific Northwest National Laboratory.
Isotope Ratio Analysis Combats Terrorism
The analysis of stable isotopes ?forms of an element that are stable because they do not decay radioactively ?started out as a way to learn about how ecosystems work, based on how environmental factors affect the proportions of various isotopes in plants, animals, soil and air. Later, stable isotopes in sediments or other materials were used to learn details about prehistoric environments, such as changing temperatures over time.
In recent years, Ehleringer pioneered the use of stable isotopes to study what has been dubbed "the ecology of terrorism." He has helped the Central Intelligence Agency, Federal Bureau of Investigation, Secret Service and Drug Enforcement Administration.
Several years ago, Ehleringer analyzed counterfeit U.S. $100 bills and showed cotton in the counterfeits had different oxygen isotope ratios than Texas-grown cotton in legitimate bills. Early counterfeits had cotton that isotope analysis indicated was grown in a wet, cool climate, while later versions came from a dry, warm climate. That confirmed the government's belief the counterfeiters had ties with terrorists who moved from Eastern Europe to the Middle East.
In 2000, the Drug Enforcement Administration began using Ehleringer's method to test thousands of drug samples each year. Slight differences in the nitrogen-15-to-nitrogen-14 ratios helped Ehleringer distinguish soils where coca plants were grown, while ratios of carbon-13 to carbon-12 revealed plants grown in humid versus drier climates. That let the DEA distinguish cocaine from Peru, Colombia, Bolivia or Ecuador.'"/>