Purdue University Chemistry professor R. Graham Cooks unveiled a new scientific discovery in Friday’s issue of the journal Science. It appears that human fingerprints can determine more than just who you are. They also contain extremely small traces of what someone touched, what someone ate or whether any drugs were taken.

The researchers used a technique called DESI, pioneered by him and his collaborators in 2004. In this revolutionary method, researchers spray microscopic droplets of water onto a sample. The droplets form a film that dissolves chemicals. Some of the additional droplets splashed bounce back and are sucked into a tube. They are thus heated inside the tube; they break into smaller molecules which are afterwards identified according to their molecular weight.

Although this may sound somewhat complicated, it is not. Mass spectrometers, Cooks says, are among the most sensitive and precise tools available to the chemist. “When they really need answers in CSI — they put things in the mass spec,” he adds. .

The testing method could be available for use in two year’s time or so, Cooks said. But the good news is that it can also be used in the medical field to identify the presence of disease in the human body.

If a DESI analyzer can be miniaturized and automated into a surgical tool for instance, a doctor can see if molecules associated to cancer are present. “That’s the long-term aim of this work,” Dr. Cooks said.

Additional co-authors of the paper are Nicholas E. Manicke and Allison L. Dill, graduate students in Purdue's chemistry department.

DESI is not the first technique that’s been used for finding chemicals in fingerprints. There is also a technique that analyzes chemicals by scanning them with a laser.