Residual solvents testing checks how much of the solvents used in, or contaminating, an extract remain in the finished product. The standard method is headspace gas chromatography: the sample is warmed in a sealed vial and the vapour above it is analysed, typically with FID or MS detection. Panels cover common extraction solvents (butane, propane, ethanol, hexane, heptane, acetone, isopropanol) and sometimes contaminants such as benzene.
In practice
This test applies mainly to solvent-based concentrates, though some markets require it for any extract. A COA lists each solvent in ppm (µg/g) against a limit; limits vary widely by solvent and jurisdiction, with lower-toxicity solvents generally allowed at higher levels. Solventless products such as rosin and ice water hash should read ND, though some markets still test them. GenetixBay doesn't cover extraction methods; this entry defines the test only.
ppm = µg/g. Results are compared with solvent-specific action limits.
Don't confuse with
- Terpene test: also GC, but measuring aroma compounds rather than solvents.
- Solventless: describes a production method; the test confirms the outcome.
Gas chromatography (GC) separates volatile compounds in a heated gas stream; it is used for terpenes and residual solvents and decarboxylates acid cannabinoids in its hot inlet.A COA (certificate of analysis) is a lab's signed report of what it measured in a specific sample, such as cannabinoids, terpenes, moisture and contaminants, with methods and limits.Solventless describes cannabis concentrates made only by mechanical or physical separation, using screens, ice water, heat or pressure, without chemical solvents.Rosin is a solventless concentrate: resin squeezed out of flower, kief or hash using heat and pressure, then collected as an oil free of plant material.Bubble hash, or ice water hash, is a solventless concentrate made by separating trichome heads from cannabis in cold water and collecting them on graded mesh bags.ND (non-detect) on a COA means the compound was not found at or above the method's limit of detection; it does not mean the amount is zero.A terpene test measures the individual terpenes and total terpene content of a sample, usually by GC-FID or GC-MS, reported in % w/w or mg/g.A concentrate is any cannabis product in which the trichome resin has been separated from plant material, giving far higher cannabinoid and terpene content than flower.The LOD (limit of detection) is the lowest amount of a compound a method can reliably tell apart from zero, but not necessarily measure accurately.
