Resumen de CBN and D9-THC concentration ratio as an indicator of the age of stored marijuana samples*

S.A. Ross, Mahmoud A ElSohly

• The concentration of D9-tetrahydrocannabinol (THC) and cannabinol (CBN) in cannabis plant material (marijuana) of different varieties stored at room temperature (20-22o Celsius (C)) over a four-year period was determined. The percentage loss of THC was proportional to the storage time. On average, the concentration of THC in the plant material decreased by 16.6% ±7.4 of its original value after one year and 26.8% ±7.3, 34.5% ±7.6 and 41.4% ±6.5 after two, three and four years, respectively. A relationship between the concentration ratio of CBN to THC and the storage time was developed and could serve as a guide in determining the approximate age of a given marijuana sample stored at room temperature.