What to Look for in
Laboratory analysis reports
Knowing the content of a product is very important when you are using it to treat a condition or someone with additional aliments that may cause more complications. A good manufacture should happily supply a certificate of analysis for any of their products, which has been performed by an independent accreted laboratory.
Laboratory tests are often expensive, time consuming and can be un-reliable, due to the methodology applied, however manufacturers should make this part of their process and factor in an addition costs and time. Testing is there for quality assurance be that consistency or safety, they give the customer confidence in the product and reduce any potential harm. Without a certificate of analysis (COA) you are blind to how much and exactly what medication you are administrating.
What we are looking for and why?
There are a number of tests that should be performed on the sample and are summarised in the table below these include:
Microbial and micro toxins – this is to check the product is free from human pathogens, such as E.Coil, salmonella to mention a few. Other microbes include mould such as botrytis, powdery mildew and Aspergillus which can grow on the plants and in the plant. These can also cause problems in humans, particularly if a patient is immunosuppressed.
Methods such as Agar plate and qPCR are used to detect and measure these. Agar is an old school technique and takes time to grow and identify the microbes in petri dishes. qPCR is a new technique that uses the DNA of the microbe to detect it and quantify it so you know the levels of the contamination. This is also a much more precise technique and can differentiate between harmful and harmless pathogens of the same species.
Heavy metals – cannabis is what is known as a bioaccumulator and loves to uptake heavy metals. It is often used to clean soil which has been contaminated in the past in a process known as phytoremediation. These metals are then stored in the cells of the plants and are then concentrated in extracts that are used for medication. Problematic metals include cadmium, lead, mercury, arsenic, nickle and zinc which have been well documented to cause many issues in humans if ingested.
A highly sensitive method called Inductive coupled plasma mass spectrometry is used to detect these elements, unfortunately this is all it can detect, therefore increase’s the cost of a full analysis.
Solvents residues - In order to extract the cannabinoids from the plant material, solvents are required as cannabinoids are insoluble in water. Some of these like ethanol or butane are left behind in the product which you are then consuming. Methods such as GC-MS can be used to detect these.
Pesticides – During the cultivation of the plants, there are often problems with insects such as spider mite, thrips and aphids along with mould such as powdery mildew. These all reduce the yield of the plant and can also make it un consumable. Farmers will use pesticide to combat these problems, which them become concentrated in the end product. Often farmers will not us any of these pesticide, but the neighbouring field will. Drift can then occur and contaminate the crop. As I mentioned earlier cannabis is very good as accumulating compounds and taking them up. Soil which was treated 20 years ago with a pesticide may also be another source of contamination.
Techniques like GC/MS are used to detect these compounds.
Cannabinoid profile – this report what cannabinoids are present and what concentration they are within the sample. It will also inform of us the ratio of them to one another. Techniques such as HPLC-UV, GC/FID and GC/MS can be used with high sensitivity. New cheaper up and coming techniques include FIR and NMR.
Terpene profile – terpenes form part of the entourage effect and can be the cause of sensitivity or adverse effects. These also work with the cannabinoids to bring more therapeutic benefits. Knowing what and how much of each terpene can allow a better tailoring of a medication for a patient.
There are a lot of methodology out there and a lot of new
|High performance Liquid chromatography||HPLC-UV||Cannabinoids||High|
|Inductively coupled plasma mass spectrometry||ICP-MS||Heavy metals||Very highly|
|Liquid chromatography mass spectrometry||LC-MS||Pesticides||High|
|Terpenes, Pesticides cannabinoids and solvent residues.||Very highly|
|Infar Red spectroscopy||IR||THC, CBD only currently||low|
|Nuclear magnetic resonance||NMR||Cannabinoids||Medium to high|
|Quantitative polymerase chain reaction||qPCR||Microbes and strain||High|
|Streaking plate method||Plate||microbial||medium|
|Thin layer chromatography||TLC||THC and CBD||Low|
Why is it so expensive?
There area number of reason analysis costs so much, the main one being the standard solutions that are required for the analysis. These are very highly purified solution of a specific concentrate which has been guaranteed by an independent accredited laboratory. A lot the compounds in question are very rare in a pure form and require laborious purification techniques. A skilled technician is also required to prepare the samples and operate instruments that can cost as much as £150,000 along with the running costs and consumable such as Argon. Multiple instruments are also required in order to test for everything and the more compounds you want identify the more standards are required.
The accreditation and licences a laboratory required to hand these substances also comes at a cost and is factored into the final price of the analysis.
Why are there various between laboratories results of the same sample?
Currently there are no standardised methodology for performing tests on cannabis-based products, therefore each lab can use a different methodology, be that the sample preparation/extraction or the type of analytical instrument used. Some methods are more sensitive than others, meaning they can differentiate compounds better and detect them at lower concentration. If labs are using different methodology comparing the results is more difficult, as the sensitivity will differ. Its like comparing apples with oranges!
Another reason maybe how they calibrate the instrument, this can be with external standard curve, where a set of solutions of know concentrations are run on the instrument and used to compare to the samples readings. Other methods include internal standards. Both of these method accuracies depend on the standards being prepare fresh every analysis, which can be costly to the lab.
Questions to ask a lab
- What is the LOD of the method?
- How do they calibrate the instrument? – Internal standard or external.
- How often do they prepare the calibration standards
- Where do they obtain their standards from?
- What methodology do they use?
- How many replicates do they performed per sample?
- What accreditation do they have?