Scientists have developed a fast-acting, highly sensitive fingerprint test to determine whether a person has recently used cocaine. The new tool comes as a result of the first large scale study of cocaine users and may lead to similar tests designed to detect other Class A substances.
Researchers from the University of Surrey in England and the Netherlands Forensic Institute and Intelligent Fingerprinting take the sample with chromatography paper as part of a technique known as paper spray mass spectrometry. The test is able to analyze cocaine levels in the fingerprints.
“This is a real breakthrough in our work to bring a real time, non-invasive drug-testing method to the market that will provide a definitive result in a matter of minutes — we are already working on a 30-second method,” said study co-leader Dr. Melanie Bailey from the University of Surrey.
“And, as with previous methods we have developed, it is non-invasive, hygienic, and can’t be faked — by the nature of the test, the identity of the subject, and their drug use, is all captured within the sample itself.”
The researchers analyzed fingerprints from a group of patients seeking treatment at drug rehabilitation centers, as well as a larger group with no known history of drug use. All participants washed their hands before the test in a variety of ways, and then samples were collected on the prepared chromatography paper.
The fingerprint is developed using chemicals, so that the ridges of the fingerprint (and therefore the identity of the donor) can be established prior to analysis. When cocaine users metabolize the drug, they excrete traces of benzoylecgonine and methylecgonine, and these chemical indicators are present in fingerprint residue.
These traces can still be detected even after hand-washing.
“Paper spray mass spectrometry is gaining increasing popularity in forensic circles because it is incredibly sensitive and is very easy to set up a testing system — the units will save laboratories time,” said study co-leader Dr. Catia Costa, also from the University of Surrey.
“This is the first time it has ever been used to detect the presence of drugs in fingerprints, and our results show the technique was 99 percent effective in detecting cocaine use among the patients.”
Drug testing is used routinely by probation services, prisons, courts, and other law enforcement agencies; however, traditional testing methods have limitations. For example, when bodily fluids are tested, there can be biological hazards and often a requirement for particular storage and disposal methods.
It is expected that this new technology will lead to drug tests for law enforcement agencies within the next decade.
The new findings are published in the journal Clinical Chemistry.
Source: University of Surrey