DETERMINATION OF DELTA(9)-TETRAHYDROCANNABINOL LEVELS IN BRAIN-TISSUEUSING HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH ELECTROCHEMICAL DETECTION

Delta(9)-Tetrahydrocannabinol (Delta(9)-THC) is the major psychoactive component of cannabis. To assist in investigating the mechanism(s) of action of Delta(9)-THC, a convenient method for determining its level s in brain tissue is required. We now describe a method for determinin g nanogram quantities of Delta(9)-THC in rat brain tissue. The method employs solvent extraction with methanol-hexane-ethyl acetate, followe d by analysis using liquid chromatography with electrochemical detecti on. Overall recoveries were greater than 80%. The relationship between the peak-height ratio for processed standards extracted in the presen ce of tissue (Delta(9)-THC/internal standard) and the amount of Delta( 9)-THC added was shown to be linear within the range of concentrations examined, Quantitative measurements of Delta(9)-THC in different brai n regions following the intravenous administration of Delta(9)-THC are presented as examples of the applications of this method.