Enhancing Cannabinoid Detection: The Crucial Role of Boric Acid Complexation in Electroanalytical Determination

Cannabis remains nowadays one of the most commonly used drugs of abuse in Europe, with 23% of young adults and adults reporting use in the last year [1]. Its psychotropic effects stem from Δ9-tetrahydrocannabinol (Δ9-THC). Recently, products with low Δ9-THC levels but high cannabidiol (CBD) content have become available on the market, posing new challenges for cannabinoids detection and analysis. It is worth observing that cannabinoids are biosynthesized in their acid forms in the plant tissues, so Δ9-THCA and CBDA are the primary compounds found in C. sativa plant [2]. Our research group has been working for years on the development of innovative electrochemical sensors for the rapid detection of cannabinoids. In this context, it is essential to define measurement conditions capable of emphasizing the peculiarities of the electrochemical signals between the different analytes to ensure their reliable detection, thus achieving significant results such as the discrimination between legal and illegal C. sativa plants [3]. We have observed the importance of the presence of boric acid, added to the electrolyte medium due to the usage of the Britton-Robinson buffer, to differentiate the electrochemical signals of neutral cannabinoids from their acid counterparts. The hypothesis of an effective interaction between Δ9-THCA/CBDA and boric acid, which has such significant analytical implications, has been investigated using electrochemical techniques, NMR, and fluorescence. The interesting results obtained may contribute to the development of increasingly effective detection systems.