Cannabis Analysis: Potency Testing Identification and Quantification of THC and CBD by GC/FID and GC/MS

Analysis of cannabis has taken on new importance in light of legalized marijuana in several states of the USA. Cannabis contains several different components classed as cannabinoids. Primary cannabinoids of interest are tetrahydrocannabinol (THC), cannabidiol (CBD) and cannabinol (CBN). Positive identification and quantification of the THC/CBD ratio is a primary objective in the analysis of cannabis. Cannabis is analyzed for several different purposes. This application note will concentrate on the potency identification and quantification of THC and CBD in cannabis by Gas Chromatography. Other application notes will cover potency by HPLC, pesticide analysis and residual solvent analyses.

As of 2014, Cannabis has been legalized in 20 states in the USA and the District of Columbia. Possession is still illegal by Federal statutes. This can influence interstate transportation of cannabis products, but it can also influence laboratory possession of cannabis for testing purposes. Consult state regulatory agencies for proper licensing requirements. 

For recreational marijuana, the psychoactive THC is the primary component of interest. Desirable traits of recreational cannabis would include high levels of THC and low levels of CBD and CBN. This information can be used to compare the relative strengths of the plant material based on THC content. Higher content THC plant material can demand higher prices. This information is valuable to growers, dispensaries and taxing authorities.