Cocaine use can now be detected simply by testing a single fingerprint, according to researchers at the University of Surrey. Previous techniques to look for cocaine in fingerprints were able to tell whether or not a person touched the drug, but could not detect if it was in a person's system.

Mass spectrometry is a technique used in chemistry to analyze the composition of a chemical sample, and the process was used to study fingerprints of people in drug treatment. The results were measured against standard tests of saliva to determine the efficacy of the new testing procedure.

Benzoylecgonine, produced during the metabolization of cocaine into the human body, can be detected in the fingerprints of users, along with a cocoa byproduct known as methylecgonine.

"The beauty of this method is that, not only is it noninvasive and more hygienic than testing blood or saliva, it can't be faked. By the very nature of the test, the identity of the subject is captured within the fingerprint ridge detail itself," Melanie Bailey of the University of Surrey said.

Solvent was sprayed onto a slide containing a fingerprint using a technique called desorption electrospray ionisation (Desi). This method has been used before in forensic investigations, but this is the first time the technique has been utilized for drug testing.

Several private companies are already looking for ways to cash in on the new finding, by developing inexpensive test kits that could be sold to law enforcement organizations, drug treatment centers and worried parents. Blood tests require trained personnel to administer, and privacy concerns surround urine tests on the streets. Handling bodily fluids could be hazardous to officers, and current tests often have to be sent to outside laboratories for analysis.

Police around the United States have long sought simple, portable drug tests to examine subjects for driving under the influence. In Washington state, where marijuana is currently legal for recreational use by adults, intoxication levels have been set at five nanograms of active THC per milliliter of blood.

Researchers at Washington State University have recently developed a breath test which can detect cannabis use. However, law enforcement officials there say they will wait for further testing before deploying the tests out in the field with their officers.

It is anticipated portable drug tests using this technology could be ready for law enforcement agencies to use within the next decade.

"We are only bound by the size of the current technology. Companies are already working on miniaturized mass spectrometers, and in the future portable fingerprint drugs tests could be deployed. This will help to protect the public and indeed provide a much safer test for drug users," Bailey said.

Development of the new fingerprint test to detect cocaine was profiled in the Journal Analyst.

Photo: Tanjila Ahmed | Flickr

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