Medical cannabis in the focus of the Ph. Eur.: requirements for pesticide analysis

Medical cannabis in the focus of the Ph. Eur.: requirements for pesticide analysis

Medical cannabis is characterised by its high content of specific constituents. The European Pharmacopoeia (Ph. Eur.) monograph on cannabis flowers differentiates between three types of cannabis:

• THC-dominant strains
• balanced THC/CBD strains, and
• CBD-dominant strains

All three types contain high cannabinoid concentrations, which are usually greater than 5 % and may be as high as 30 % in some THC-dominant varieties.

Apart from undergoing quantitative analysis, medical cannabis must also be tested for the presence of contaminants and residues in accordance with the requirements of the European Pharmacopoeia. These specify mandatory testing for pesticide residues as laid down in monograph 2.8.13 Ph. Eur. The range of substances defined in Table 2.8.13-1 includes many active ingredients that are now prohibited and the limit values for some of these are very low.

Our solution: valid pesticide analysis for medical cannabis

We have developed a highly efficient method that uses an optimal combination of two selective and highly sensitive techniques – GC-MS/MS and LC-MS/MS – to cover the specified range of substances. Furthermore, we offer an extended scope of testing for relevant LC substances that are frequently detected in dried botanical drugs (reference to the publication on the BAH database evaluation).

Challenges for analysis

Medical cannabis constitutes a particularly challenging matrix, not only because of its high cannabinoid content, but also its concentrations of resins, terpenes and lipids. If standard extraction methods are used, the constituents are almost entirely transferred into the sample extract and can cause analytical interference during pesticide measurement, as well as contaminating the analytical equipment.

We are now able to selectively eliminate or significantly minimise these matrix effects by means of a purification process that has been specifically developed for this purpose. It enables us to reliably determine all of the required active ingredients with the necessary specificity and sensitivity.

We have validated this special procedure in its entirety in accordance with the parameters specified in monograph 2.8.13 and offer regulation-compliant validation documentation for the substance spectrum laid down in the Ph.Eur.

Method characteristics at a glance

• Combined analysis by means of LC-MS/MS and GC-MS/MS
• Determination limits from 0.01 mg/kg
• Clearly laid out cannabis-specific determination limit data sheet
• Two scopes of analysis available:
  • Eur. Cannabis
  • Eur. Cannabis PLUS (extended scope of substances)
• Sample preparation based on QuEChERS extraction as laid down in the Official Collection of Methods of Analysis (ASU) according to § 64 German Food and Feed Code (LFGB) L00.00-115
• Reproducible results with high precision and excellent recovery rates – even for this complex matrix

Special requirements for the handling of medical cannabis

Due to the high THC content, the samples are subject to special handling requirements. Complete documentation is mandatory, from sample receipt right through to proper disposal of remaining material. This process is firmly established at PhytoLab and is continuously monitored by our MedCan officer.