Supercritical Fluid Extraction of Tetrahydrocannabinol from Marihuana Study of the Effect of Particle Size

In order to obtain reproducible quantitative result for constituents of plant materials, the grinding of sample and extraction of a sieve fraction with a predefined average particle size is advised. The aim of the present study is to investigate the influence of particle size of marihuana on the extraction recovery of THC (delta-9-tetrahydrocannabinol) applying supercritical fluid extraction as well as the study of the effect of sieving of the sample on the quantitative results obtained by high performance liquid chromatography. It could be stated that marihuana samples can not be characterised in terms of potency by determination of the THC content of a selected sieve fraction of the groundmaterial and subsequent calculation for the content of thewhole sample, because owing to the significant inhomogenity of the different sieve fractions as far as the morphological composition is concerned, false THC content can be calculated for the whole sample.