Researchers at the National Institute of Standards and Technology (NIST) and the University of Colorado Boulder teamed up to research cannabis detection methods. The findings published in the Journal of Breath Research offered insights into developing an effective breathalyzer technology for THC.
The researchers collected breath samples from participants both before and after they smoked high-THC cannabis. Instead of relying on commonly used handheld devices to measure the amount of THC in participants' breath, the researchers used a mobile pharmacology lab designed by the UC Boulder faculty. The mobile site allowed them to collect breath and blood samples soon after participants consumed cannabis. The mobile lab would park outside participants' homes to collect breath samples after participants smoked high-THC cannabis prepared by a Colorado licensed dispensary.
Participants provided pre-use blood and breath samples since THC can persist in the bodies of people who frequently use cannabis for a month or more, even after the effects of the drug have subsided. The participants returned home after submitting the pre-use samples and then smoked cannabis. Immediately after, they visited the mobile van to submit the second blood and breath sample. Participants blew into a tube containing an "impaction filter." This device captured aerosols from their breath. Then the researchers extracted the material caught in the filter and measured the THC and cannabinoids concentrations using liquid chromatography with tandem mass spectrometry to analyze the samples. Scientists believe that the exhaled aerosol particles contain THC. Since the total volume of aerosols can be tiny, it is challenging to measure their THC content. The researchers believe that more research is needed to demonstrate the effectiveness of this cannabis breathalyzer.