This application describes an analytical method for the chromatographic separation and quantitative monitoring of seven primary cannabinoids, including THC and THC-A, in cannabis extracts by HPLC with PDA detection. Naturally occurring cannabinoids, the main biologically active component of the cannabis plant, form a complex group of closely related compounds, of which 113 are known and 70 are well described. Of these, the primary focus has been on ?9-tetrahydrocannabinol (THC), as the primary active ingredient due to its pharmacological and toxicological characteristics, upon which strict legal limits have been enforced.