A novel method for monitoring of Δ 9 -tetrahydrocannabinolic acid and cannabidiolic acid thermal decarboxylation reactions in cannabis plant

Abstract The decarboxylation reaction for acidic cannabinoids is an important step in the use of cannabis. The effect of heating rates and cannabinoid composition on the decarboxylation process was studied. The TG/DTG curves of Δ9-tetrahydrocannabinolic acid (THCA) and cannabidiolic acid (CBDA), for a first time, compared the decarboxylation dynamics at different heating rates. Moreover, HPLC analysis on the plant sample after TG run presented evidence of cannabinoids conversion. The results showed that THCA had a higher decarboxylation reaction temperature than CBDA. In all cases, a significant loss of acid and neutral cannabinoids was observed at elevated heating rates in the absence of oxygen. THCA-dominant cannabis plant show lower activation energy (Ea) on THCA decarboxylation reaction. These findings were used to improve the decarboxylation condition and increase THC or CBD concentration.