Sample preparation of cannabis plants

for example as marijuana (dried leaves and flowers) or as hashish (the resin of the female plant). Today Tetrahydrocannabinol (THC) and Cannabidiol (CBD) are particularly isolated and researched from the multitude of active substances contained in the plant (in addition to other cannabinoids and terpenes) as pharmacologically effective components.

Sticky and tricky – the translucent structures that are seen producing from the cannabis flower are trichomes. These structures are resinous & sticky and contain the vast majority of biologically active cannabinoid and terpene compounds. This is a challenging material for milling - see picture on the right.

The most common method to extract the active ingredients from the cannabis plant is supercritical CO₂ extraction. At above 31°C and with high pressure the CO₂ gets into the "supercritical" state. It now acts as a solvent. It is passed through a chamber containing the plant material. The CO₂ has still the density of a liquid, but can fill the entire chamber like a gas. This is ideal for extraction as it does not cause denaturation or damage to the product.

The CO₂ extracts the cannabinoids and terpenes from the plant. The result is a safe, high-quality, pure oil, which can now be processed for various therapeutic applications. The producers of these cannabis oils naturally want to make the extraction process as efficient as possible. That means: the highest possible yield of the ingredients in the shortest possible time.

The FRITSCH Universal Cutting Mill PULVERISETTE 19 is also used to grind samples for the potency testing or to examine the material for pesticide residues. In order to optimally adapt the cutting performance to the sample, the speed of the rotor can be regulated between 300 rpm to 3000 rpm.

As with all mills used in analytical laboratories, simple cleaning is desirable. The concept of the Clean Design was used for the FRITSCH PULVERISETTE 19: the grinding chamber can be opened completely, all grinding parts can be removed without tools for easy and fast cleaning. Cross contamination can be effectively avoided.

The FRITSCH PULVERISETTE 19 is also available in a 316L stainless steel version for use in the pharmaceutical sector.