Residual Solvents Testing
Residual Solvents Testing
With the demand for cannabis rising, a wide range of products have been developed for the consumer. When butters, oils, wax, or shatters are created, solvents (volatile organic compounds) are needed to extract the cannabinoids from the plant. Since there is a wide range of production techniques, many types of solvents are involved during these manufacturing processes. These solvents have different levels of hazards to humans. For safety and health concerns, solvents are to be removed from the product after extraction. However, small quantities of these solvents may remain in the products and are commonly known as residual solvents. These residual solvents are classified according to their risk to human health. There are three classes of such solvents.
- Class 1: Known and suspected carcinogens and environmental hazards
- Class 2: Disease causative agents and solvents that possess irreversible toxicity
- Class 3: Low toxic potential
A GC-FID with headspace autosampler systems can be used for quantitative analysis of the residual solvents. Solvent molecules will evaporate in the headspace and be injected into the GC for separation followed by detection. For better confirmation and more versatility, GC-MS systems are becoming more popular. GC-MS systems are able to identify the exact compounds eluted at different times by determining the molecular mass of each compound. This provides better confirmation for the known residual solvents, and also allows detection for unknowns.
| Common Residual Solvents |
|---|
| Acetone |
| Butane |
| Carbon Dioxide |
| Dichloromethane |
| Diethyl-ether |
| Ethanol |
| Heptane |
| Hexane |
| Isopropanol |
| Methanol |
| Pextane |
| Propane |
| Toluene |
Gas Chromatography Systems
GC-FID systems can also be used to screen for residual solvents and pesticides. GC systems can also be used to quantify the potency of cannabis samples by measuring cannabinoids, and terpenoids.
Gas Chromatography- Mass Spectrometry Systems
GC-MS systems have a wide range of use for cannabis testing. A GC-MS is required for performing terpenoid profiling, and is a popular option for detecting residual solvents. For detecting chlorinated hydrocarbons, organophosphates and pyrethroid type pesticides, a GC-MS system is well suited.