Chemists make progress toward a marijuana breath analyzer

A chemist and his colleagues at the University of California, Los Angeles (UCLA) are now closing in on their goal of developing a wearable tool similar to a breathalyzer that can detect THC in a person’s breath after smoking pot. marijuana.

In a published article in the review organic lettersNeil Garg, professor of organic chemistry at UCLA, and researchers from the UCLA startup ElectraTect Inc. describe the process by which THC introduced, in solution, into their laboratory-made device can be oxidized, creating an electrical current whose the strength indicates how much psychoactive compound is present.

With the recent legalization or decriminalization of marijuana in many states, including California, the availability of a breathalyzer-like tool could help make roads safer, the researchers said. Studies have shown that marijuana use impairs certain driving skills and is associated with a significantly elevated crash risk.

In 2020, Garg and UCLA postdoctoral researcher Evan Darzi found that removing a hydrogen molecule from the larger THC molecule caused it to change color in a detectable way. The process, known as oxidation, is similar to that used in alcohol breath analyzers, which convert ethanol into an organic chemical compound through the loss of hydrogen. In most modern breath alcohol analyzers, this oxidation leads to an electrical current that indicates the presence and concentration of ethanol in the breath.

Since their discovery in 2020, researchers have worked with their patent-pending oxidation technology to develop a THC breath analyzer that works in a similar way. ElectraTect has exclusively licensed the patent rights from UCLA.

How the new device works

In the new article, Darzi, now CEO of ElectraTect, Garg and ElectraTect researchers detail how their new lab-scale THC-powered fuel cell sensor works. When THC (scientifically known as Delta-9-tetrahydrocannabinol) comes into contact with a negatively charged electrode, or anode, on one side of the device’s H-shaped glass chamber, it oxidizes into a new compound called THCQ, sending electrons through the chamber to a positively charged electrode, or cathode, on the other side, generating a measurable electric current. The higher the concentration of THC molecules, the stronger the current.

This breakthrough marks the first use of THC to power a fuel cell sensor. The researchers said they expect the relatively simple and inexpensive technology, once perfected, can be scaled up for economical mass production, and they are now working to refine the device to detect and measure the THC in exhaled air and reduce it to a more compact. size suitable for use in a portable breath analyzer or ignition killer – a breath analyzer connected to a vehicle’s ignition that prevents it from starting if THC is detected.

Making marijuana testing easier and fairer

Beyond the implications for improving road safety, the technology has the potential to make marijuana law enforcement fairer, the researchers said. Generally, urine or blood tests are used to detect the presence of THC in drivers. Not only are these tests difficult to administer at the roadside, but because the compound can linger in the body for weeks after marijuana use without any residual cognitive effects, these tests are not always helpful in identifying impaired drivers. weakened. This ambiguity can result in fines, jail time, or loss of employment, even if an individual is not high at the time of the test.

These issues, the researchers say, highlight the need for innovative, easier-to-use, and more accurate forensic technologies to detect recent marijuana use. And while a commercial marijuana breath analyzer based on their technology would still be years away, Darzi and Garg pointed out that such a tool could ultimately have benefits beyond road safety and law enforcement. the law. Their technological breakthrough, they said, could ultimately be used in any situation where fair marijuana testing is essential, including in the workplace, where employees might use machinery, or even at home, where individuals may one day be able to use it proactively… even before they get behind the wheel.

– This press release originally appeared on the University of California – Los Angeles website