ISOTOPES REVEAL DRUG'S HOMETOWN

You don't need to be too much of a snob about French wine to tell a Sancerre
from a Savennieres, or a St.-Estephe from a St.-Emilion. Even small taste
hints -- a touch of flintiness here, some fruitiness there -- can be enough
to pin down a wine's origin.

Cocaine, according to new research, gives even subtler clues as to where it
came from. This information should be of use, not to connoisseurs of the
drug, but to law enforcement agents.

Researchers from the University of Utah and the Drug Enforcement
Administration, reporting in the journal Nature, say that by analyzing the
chemical signature of a sample of cocaine, they can determine where in South
American the drug's raw material, coca leaves, were grown.

The researchers analyzed the ratio of certain isotopes of carbon and
nitrogen in the cocaine, recognizing that these ratios differ depending on
the conditions in which the coca was grown. The scientists also analyzed the
trace alkaloid content of the drug.

By combining the two sets of data, they were able to correctly distinguish
the origin of 96 percent of 200 cocaine samples.

The researchers say the technique should be useful in the fight against
cocaine trafficking. It can also help identify and target new
cocaine-producing areas as they develop.