A team led by researchers at the University of Surrey in the United Kingdom has developed a new, non-invasive test that's able to detect cocaine use in a patient by analyzing a single fingerprint. Unlike existing tests, the new technique is able to determine whether the subject has ingested the drug, rather than just touched it. 
 
 Drug testing is a common practice in prisons, courts and numerous other law enforcement agencies, but existing methods have significant limitations, often requiring specialist staff and off-site analysis. While not quite ready for mass introduction, the newly-developed technique could make things significantly easier. It's non-invasive, hygienic and impossible to fake, with the identity of the subject captured in the fingerprint itself. 
 
 The technique makes use of mass spectrometry to analyze patient fingerprints, searching for traces of the chemicals methylecgonine and benzoylecgonine, which are excreted by the body as the drug is metabolized. To look for these indicators in the fingerprint residue, a beam of solvent is sprayed onto the slide – a technique known as Desorption Electrospray Ionisation (DESI). The method has been used for other forensic applications in the past, but this is the first time it's been used to test for drug use. 
 
 The team believes that the technique could be introduced as a portable drug test for law enforcement agencies within the next 10 years. 
 
 "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," said the University of Surrey's Dr. Melanie Bailey. "This will help to protect the public and indeed provide a much safer test for drug users." 
 
 The research was conducted by a collaborative team from the University of Surrey (UK), National Physical Laboratory (UK), King's College London, Sheffield Hallam University (UK) and the Netherlands Forensic Institute. 
 
 The researchers published their findings in the journal Analyst. 
 
 Source: University of Surrey 

 GUILDFORD, England, May 15 (UPI) -- Drug testing has historically been an invasive process that requires some type of fluid or hair sample, but a group of researchers may have finally developed an accurate fingerprint test for cocaine use. 
 
 Using a chemistry technique called mass spectrometry, fingerprints were shown to be just as accurate at detecting cocaine in a person's system as saliva samples. 
 
 Traces of benzoylecgonine, which the body uses to metabolize cocaine, and methylecgonine, a byproduct of the coca plant that is present in cocaine, are found in fingerprint residue after a person uses cocaine. Researchers sprayed a solvent used in forensics onto fingerprint slides to test for the two excretions before comparing the results to other tests. 
 
 "For our part of the investigations, we sprayed a beam of solvent onto the fingerprint slide (a technique known as Desorption Electrospray Ionisation, or DESI) to determine if these substances were present," said lead author Dr. Melanie Bailey, a chemistry professor at the University of Surrey, in a press release. "DESI has been used for a number of forensic applications, but no other studies have shown it to demonstrate drug use." 
 
 "The beauty of this method is that, not only is it non-invasive and more hygienic than testing blood or saliva, it can't be faked," Bailey said. "By the very nature of the test, the identity of the subject is captured within the fingerprint ridge detail itself." 
 
 Several companies already are working on small spectrometers to make such tests more widely available to police, courts, rehabilitation programs and private consumers just looking to keep an eye on their children. 
 
 Law enforcement officials have been interested in easy roadside tests for drug use, and for several years companies have advertised planned devices that use sweat to test for illegal drugs. 
 
 A breath test for detecting marijuana use, recently developed at Washington State University, has shown promise, but police officials say they want the tests to be more reliable before deploying them. Washington state, where marijuana has been legalized for recreational use, set five nanograms of active THC per milliliter of blood as the legal limit of impairment. 
 
 The latest fingerprint study was published in the journal Analyst. 
 
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 Latent fingerprints provide a potential route to the secure, high throughput and non-invasive detection of drugs of abuse. In this study we show for the first time that the excreted metabolites of drugs of abuse can be detected in fingerprints using ambient mass spectrometry. Fingerprints and oral fluid were taken from patients attending a drug and alcohol treatment service. Gas chromatography mass spectrometry (GC-MS) was used to test the oral fluid of patients for the presence of cocaine and benzoylecgonine. The corresponding fingerprints were analysed using Desorption Electrospray Ionization (DESI) which operates under ambient conditions and Ion Mobility Tandem Mass Spectrometry Matrix Assisted Laser Desorption Ionization (MALDI-IMS-MS/MS) and Secondary Ion Mass Spectrometry (SIMS). The detection of cocaine, benzoylecgonine (BZE) and methylecgonine (EME) in latent fingerprints using both DESI and MALDI showed good correlation with oral fluid testing. The sensitivity of SIMS was found to be insufficient for this application. These results provide exciting opportunities for the use of fingerprints as a new sampling medium for secure, non-invasive drug detection. The mass spectrometry techniques used here offer a high level of selectivity and consume only a small area of a single fingerprint, allowing repeat and high throughput analyses of a single sample. 

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 Scientists can already tell from people’s fingerprints if they’ve touched cocaine, but a new study goes one step further, showing that fingerprints can now also reveal whether a person has ingested the drug. The study, published in Analyst, may pave the way for simpler drug testing that doesn’t require urine or blood. 
 
 In a small study, a team of researchers analyzed the fingerprints of a handful of patients in drug treatment centers using a process called mass spectrometry. Someone who uses cocaine excretes components of metabolized cocaine called benzoylecgonine and methylecgonine. The study authors showed they were able to detect the cocaine components in the residue left by the patients’ fingerprints on glass through the mass spectormetry chemical analysis technique. 
 
 “These results provide exciting opportunities for the use of fingerprints as a new sampling medium for secure, non-invasive drug detection,” the researchers write in their study. “The mass spectrometry techniques used here offer a high level of selectivity and consume only a small area of a single fingerprint, allowing repeat and high throughput analyses of a single sample.” 
 
 If such a technique could be made portable, the researchers believe it could possibly provide a simpler and less invasive alternative to current drug testing.
– Might the days of taking saliva or blood samples for drug tests be numbered? Scientists have figured out a way to use fingerprints instead, they report at Phys.org. Specifically, the researchers used a chemical analysis of the prints to determine whether a person had ingested cocaine. Currently, scientists are able to tell whether a person has touched cocaine based on their prints, notes Time, but the study in the journal Analyst takes the sleuthing a big step forward. Researchers predict that it could lead to portable tests for police departments within a decade. That's because "it's non-invasive, hygienic, and impossible to fake, with the identity of the subject captured in the fingerprint itself," explains Gizmag. Researchers used a technique known as mass spectrometry to search for telltale signs of cocaine use in the prints. "When someone has taken cocaine, they excrete traces of benzoylecgonine and methylecgonine as they metabolize the drug, and these chemical indicators are present in fingerprint residue," explains the study's lead author, out of the UK's University of Surrey. One hurdle is developing small spectrometers to make such testing portable and cheap, and UPI reports that several companies already are working on it. (In a similar vein: A study figures out how rapists who wear condoms can be caught.)