TORONTO -- In what could have far-reaching ramifications, it turns out your fingertips can give away whether you’ve recently used cocaine or even handled it.
Using only a person’s fingerprints, an experimental test can detect trace amounts of the narcotic on the skin -- even after a person washed their hands, according to new research from the United Kingdom and Ireland.
The findings, published in Scientific Reports, was carried out by University of Surrey, Forensic Science Ireland and the National Physical Laboratory.
This test could be extremely helpful for high-stakes drug testing purposes, in situations where employers or law enforcement would need to accurately tell the difference between those who touch and those who ingest cocaine.
"A fingerprint is a great way to test for drugs as it is so quick and efficient to collect,” Min Jang from the University of Surrey’s chemistry department, said in a press release. “Using our methodology, it is possible to analyze a fingerprint sample for drugs in less than two minutes.”
That speed is vastly faster than current blood tests -- the standard for testing cocaine use – which can take hours or days to complete.
The test, based on technology from private U.K. company Intelligent Fingerprinting, was determined to be accurate for up to 48 hours after a person’s contact with the drug.
It works using an analytic tool called mass spectrometry to detect benzoylecgonine -- a molecule the body makes when you use cocaine. But the test could have other uses.
University of Surrey researcher Catia Costa said the team was keen to see if a similar type of test could be used to ensure patients were given the correct dose of their prescribed medication.
She said her team was “excited about the possibilities.”
To come up with the new research, the team took fingerprint samples from 26 consenting patients getting treatment at a drug rehabilitation clinic, who all said they had taken cocaine in the past 24 hours. They were asked to give another set of prints after washing their hands thoroughly with soap and water.
The test required people to press their fingers onto a piece of specialized paper for 10 seconds.
The same process was done with participants of non-cocaine users who handled trace amounts of street cocaine. But in their cases, benzoylecgonine wasn’t found in their samples even after they had washed their hands.
Out of the total 86 samples taken, the fingerprinting technique was 95 per cent accurate. David Russell, founder and chief scientific officer at firm Intelligent Fingerprinting, boasted that the research validates their drug screening technology they’ve been using since summer 2017.
The researchers said one of the limitations of the study was not knowing just how long large doses of the drug could stay in people’s fingertips.
In an interview with weekly U.K. science magazine New Scientist, toxicology consultant David Berry, who didn’t work on the study, warned that further validation would be needed if the test was to be used to detect cocaine in fingerprints left at a crime scene.
