Isolation of Δ9-THCA-A from hemp and analytical aspects concerning the determination of Δ9-THC in cannabis products

A simple procedure based on a common silica gel column chromatography for the isolation of Δ9-tetrahydrocannabinolic acid A (Δ9-THCA-A) from hemp in a multi-milligram scale is presented. Further, the decarboxylation reaction of Δ9-THCA-A to the toxicologically active Δ9-tetrahydrocannabinol (Δ9-THC) at different analytical and under-smoking conditions is investigated. Maximal conversion in an optimised analytical equipment yields about 70% Δ9-THC. In the simulation of the smoking process, only about 30 % of the spiked substance could be recovered as Δ9-THC.