Understanding your COA’s shouldn’t be rocket science
Chromatography works by dissolving the cannabinoids in a solvent and then injecting them into a packed column, which is essentially a filter. Because each cannabinoid has a different structure, they will all experience unique ‘friction’ with the column and so flow out at different, repeatable times. The separated slugs of cannabinoids then pass by a UV lamp shining through the liquid and into a detector. The process boils down to: “at 4 minutes after injection, CBD and only CBD will come out.”
In accordance with OAR 333-064-0100, Total THC=0.877*THCA + THC. The same formula applies to total CBD. The reason is that under heat, THCA decarboxylates into THC, the psychoactive component of cannabis. This means that a set of carbon, oxygen, and hydrogen atoms are lost, so on a per molecule basis the THC weighs 87.7% of THCA. Reporting the total standardizes the regulatory rules.
What Does <LOQ mean?
No analytical device can ‘measure zero’. Much like a kitchen scale has a minimum weight that it can read, potency measurement has a minimum Limit of Quantitation. So, below this value an analyst will report ‘<LOQ’ rather than 0.0%.
Moisture content is simply the concentration of water within a sample. It is used to correct a flower sample’s potency in order to report a % dry weight, or the cannabinoid potency as if all water had been removed. This standardizes the reporting procedure. Wouldn’t it be a bummer for your 20% strain to test as 5% just because it was rained on? We determine moisture content in a very straightforward way: weigh the sample, dry the sample, reweigh the sample and then use the difference in weight as the lost moisture. For consumable flower the moisture must be brought below 15%, per OAR 333-007-0420.
Water activity is tested for consumer safety purposes. It represents how available the water is on the surface of a product. It’s a useful safety measure because the less available water there is, the harder it is for bacteria and mold to grow. This extends the shelf life. Water activity is measured by placing the sample in a sealed container with a relative humidity meter, then reported on a scale from 0-1.0. Samples under 0.65 are compliant.