HPLC Analyses of Δ9-Tetrahydrocannabinol and 11-Nor-Δ9-tetrahydrocannabinol-9-carboxylic Acid in Human Plasma

Detection of marijuana use in humans has been a pressing need for law enforcement officials as well as forensic scientists. Work performed in our laboratories has centered principally around finding suitable techniques for identifying prior use of marijuana by analysis of various body fluids following marijuana smoking. A guiding axiom in initiation of this work was previous findings that Δ 9 -tetrahydrocannabinol produced the psychotomimetic effects (2) as well as some of the observed physiological responses (3) following marijuana smoking. Marijuana contains four constituents of similar structure: Δ 9 -tetrahydrocannabinol (I); cannabidiol (II); cannabinol (III); and cannabichrome (IV) which appear in varying quantities depending upon the geographic origin of the marijuana plant (4). Thus human body fluids would most likely contain these constituents as well as possible metabolites of each. Metabolism of I in humans has been studied by several groups (5-8) with findings that ll-hydroxy-Δ 9 -tetrahydrocannabinol (V) and ll-nor-Δ 9 -tetrahydrocannibinol-9-carboxylic acid (VI) are the principal