Development and optimization of the process of decarboxylation of tetrahydrocannabinoic acid, followed by FTIR detection of tetrahydrocannabinol in medicinal Cannabis

Aim of the study: Conversion of tetrahydrocanabinoic acid (THCA) to tetrahydrocannabinol (THC), is the main reaction essential for the use of cannabis,Cannabis indica L. buds in medicinal purposes. Therefore, the aim of this study was to develop and optimize the thermal treatment of Cannabis buds, required for the reaction of decarboxylation of THCA to THC followed by FTIR technique. Materials and methods: Cannabis buds were heated on aluminum shelves,programmed by heating oven POL EKO SL 400. Temperature program was strictly monitored and changes were recorded on every 5 minutes. Mid Infrared spectra were collected for each sample and temperature, respectively, using Perkin Elmer Spectrum Two™ coupled to an UATR accessory in spectral range of 400-4000 cm-1. Results: Changes in the infrared spectra indicated that the required elimination of water and appropriate conversion of THCA to THC were established, as the reaction progressed. Reaction of decarboxylation has occurred in temperature range from 85-120° C. Conversion of THCA to THC contributed for obtaining of high concentrations of THC which ranged 38-80% w/w. The progress of the decarboxylation enhanced the obtaining of THC. Conclusion: Monitoring of the process of decarboxylation with FTIR technique presents a fast and plausible method for controlling the conversion of acidic forms of cannabinoids to their neutral forms. The thermal treatment has shown a high yield of THC up to 80% w/w. It should be stressed out that these two methods could be ideally suited to everyday analysis because of their high performances