CHICAGO – As the cannabis derivative delta-8-THC grows in popularity, it’s important for drug tests to be able to detect and differentiate it from delta-9-THC—the primary psychoactive ingredient in cannabis. Breaking research showcased at the 2022 AACC Annual Scientific Meeting & Clinical Lab Expo demonstrates that common drug testing methods can do just that.

Over the last few years, use of delta-8 has been rising in popularity in the U.S. for two reasons. The first is that it’s known for giving users a milder high than regular marijuana, and the second is that delta-8 is unregulated at the federal level, which means that it’s legal in most states where cannabis use is still banned. However, because delta-8 products are unregulated, many contain toxic manufacturing by-products that make it more dangerous than delta-9-THC. In light of this, testing for delta-8 is needed to discourage people from taking these contaminated products as a way to circumvent drug tests. Testing is also needed to monitor the spread of delta-8 and to inform public health efforts to craft better regulations for it.

With this in mind, a team of researchers led by Uttam Garg, PhD, of Children’s Mercy, Kansas City and the University of Missouri-Kansas City School of Medicine, conducted research to see if tests that detect delta-9-THC can also detect delta-8. To do this, Garg’s team spiked negative urine samples with various concentrations of delta-8 (10-50 ng/mL) and analyzed these samples with a standard approach for detecting cannabis use. First, they screened the samples with a commercial cannabinoid immunoassay, then they followed this with confirmatory testing using gas chromatography-mass spectrometry (GC-MS).

Garg’s team found that the cannabinoid immunoassay yielded positive results for all samples with delta-8 concentrations of 30 ng/mL and higher. The GC-MS method also identified delta-8. The latter is especially significant because delta-8 and delta-9-THC are very similar at a molecular level, but the GC-MS method was able to distinguish between them due to a difference in something known as retention time. The researchers confirmed these findings in a patient sample containing delta-8.

“With our methods, we can detect both delta-8 and delta-9 isomers and distinguish delta-9 from delta-8,” Garg said. “If someone is using delta-8-THC, the immunoassay we are using and likely other immunoassays which are out on the market will detect it. Once an immunoassay positive sample has been identified, then you need a chromatographic method to separate delta-8 and delta-9 because they are very similar structurally. That’s what we did in our lab—we used immunoassay for initial screening and GC-MS to separate and distinguish the two compounds.”

Abstract Information

AACC Annual Scientific Meeting registration is free for members of the media. Reporters can register online here:

Abstract A-302: Can current immunoassay and gas-chromatography mass spectrometry (GC-MS) methods for delta-9-tetrahydrocannabinol carboxylic acid (Δ9-THC-COOH) detect Δ8-THC-COOH? will be presented during:

Scientific Poster Session

Tuesday, July 26

9:30 a.m. – 5 p.m. (presenting author in attendance from 1:30 – 2:30 p.m.)

Poster Hall, Clinical Lab Expo show floor

McCormick Place Convention Center


About the 2022 AACC Annual Scientific Meeting & Clinical Lab Expo

The AACC Annual Scientific Meeting offers 5 days packed with opportunities to learn about exciting science from July 24-28. Plenary sessions will explore artificial intelligence-based clinical prediction models, advances in multiplex technologies, human brain organogenesis, building trust between the public and healthcare experts, and direct mass spectrometry techniques.

At the AACC Clinical Lab Expo, more than 750 exhibitors will fill the show floor of the McCormick Place Convention Center in Chicago with displays of the latest diagnostic technology, including but not limited to COVID-19 testing, artificial intelligence, mobile health, molecular diagnostics, mass spectrometry, point-of-care, and automation.

About AACC

Dedicated to achieving better health through laboratory medicine, AACC brings together more than 70,000 clinical laboratory professionals, physicians, research scientists, and business leaders from around the world focused on clinical chemistry, molecular diagnostics, mass spectrometry, translational medicine, lab management, and other areas of progressing laboratory science. Since 1948, AACC has worked to advance the common interests of the field, providing programs that advance scientific collaboration, knowledge, expertise, and innovation. For more information, visit