Application Note: Loss on Drying, Cannabis Regulation and Moisture Analyzers
Determination of moisture content in cannabis and cannabis-derived products is a widespread practice and is required – at least in part – by law. Moisture levels can influence everything from product weight to shelf life to active ingredient concentration, so it is important to conduct accurate analyses.
Prominent methods for determination of moisture in cannabis are Karl Fischer titration (KF) and the loss on drying method. Karl Fischer is laborious and uses harsh chemicals. The loss on drying method is time-consuming but can be cost-effective to implement in routine laboratory work using a vacuum oven. An alternative to the drying ovens is moisture analyzers, which are also based on the LOD method but can faster, cost-effective results.
This study compares the classic oven method to the infrared method, in which two moisture analyzers - Mark 3 HP and MA160 - are tested.
Commonly Asked Questions:
- How does loss on drying differ from Karl Fischer titration?
- The Karl Fischer titration method determines only sample’s water content. This may include water from crystallization and surface absorption but does not factor in any other substances. Loss on drying also factors in the presence of volatile impurities.
- What is an example of state-mandated moisture regulation for cannabis?
- California’s Bureau of Cannabis Control requires the moisture content of properly cured cannabis flowers be below 13%. The states of Nevada and Washington have a moisture percentage threshold of 15%.