Our laboratory uses the GC / MS method to determine the cannabinoids.

• Specification of method for determination of cannabinoids


Our Limit of quantification (LOQ), as shown in the table, was determined based on the practical needs of our customers. If necessary, we are able to analyse significantly lower concentrations.


Parameters "THC total" and "CBD total" are related to the method of evaluating analytical results for different purposes. The most represented cannabinoids are acid forms THC or CBD (THCA and CBDA) in the cannabis plant. Heating this plant, the compounds lose the carboxyl group and produce their neutral forms (THC or CBD). Acid and neutral forms have different effects on the organism. For example, THCA does not act like a drug after ingestion of cannabis. On the other hand, by heating hemps during smoking, THCA changes to THC, which is already acting as a drug.

For forensic purposes as well as for cannabis certification as a technical crop, legislation prescribes a method of determination in which all THCA or CBDA are converted into neutral form. For THC, the maximum amount available in the sample in the form of both THCA and free THC is measured. For natural medicine, this approach is not appropriate because acidic and neutral forms have different biological properties. Our determination method makes it possible to determine these forms of matter separately. The parameters THC total and CBD total, which are to be known for the forensic assessment of the sample, are calculated from the results of determination of the acidic and neutral forms (this is not a simple sum).



• Amount of sample required for the determination of cannabinoids


A relatively small amount of sample is needed, but it depends on its homogeneity. In the case of ointments and oils, about 1–5 g of material is sufficient. In the case of plant cannabis, it is possible to analyse roughly the same amount (1–5 g) of powdered material, but it must be representative sample. So if you deliver 1 g of cannabis (e.g. bud hemp only), the results cannot be related to the whole plant. If you deliver mixture of bud hemp and leaves, we will homogenise all the material to be representative for the whole sample. In this case 20–50 g of sample is needed.



• Determination of cannabinoids in the Cannabis plant


When analysing cannabinoids in cannabis plants, it must be taken into account that their content varies widely in different parts of the plant. The highest content is in female flowers and leaves from the top of the plant. On the other hand, the cannabinoid content in the stem and in the seeds is practically negligible. In general, there does not exist a unified method of sample preparation. It depends more on the purpose of the analyses and the way the results are interpreted.

For the certification of cannabis varieties, the preparation procedure is defined by Commission Regulation (EC) No. 1122/2009 (the required number of plants and the vegetation phase in which the sample is taken). Only the top of female plants are selected for analysis, so seeds and stems are excluded from the sample, which can be a substantial part of the material. The results of the analysis are THC concentration in the richest part of the plant (flower and upper leaves). On the other hand, in forensic analysis, the whole material is considered to be the entire sample. For example, the whole plant (including a stem, in which the THC content is relatively small compared to the top of the plant) is a sample. Our laboratory can provide both ways and it depends on the customer's request. However, if the customer does not specify the sample preparation procedure, the laboratory will homogenize the entire sample delivered to the laboratory or its representative portion. Customers usually send us samples in amount of approx. 10 g. However, only a small proportion of this quantity is needed for the analysis itself. Larger quantities are processed only to ensure representativeness of the sample. Plants are treated in dry form, dried with mild heat to constant weight, but still contain about 15 % moisture. The results relate only to above mention state.



• Legal Aspects of Cannabis Plant Analysis


According to the Legislation, the term "cannabis plant including the top" is generally considered to be a drug. The only approved cannabis varieties (with a THC content of less than 1 %) are considered to be drugs. Our laboratory has the authorization to manipulate cannabis samples but has to keep records of their origin and manipulation. Therefore, we have to ask each customer for the information: who passes the sample, its quantity and the designation of the approved cannabis varieties.

For legal reasons, our laboratory is deliberately not taking samples of cannabis with a high THC content.



• Legal Aspects of Cannabis Plant extract / tincture Analysis


The amount of cannabis extract or tincture received by the laboratory will be registered as a narcotic. The laboratory requires the client to provide a valid authorization for the handling addictive substances pursuant to Act No. 167/1998 Coll.