A terpene test quantifies a lab-defined list of terpenes, commonly 20-40 compounds, from monoterpenes such as myrcene, limonene and pinene to sesquiterpenes such as beta-caryophyllene and humulene. Most labs use gas chromatography, by liquid injection or headspace sampling, with FID or MS detection. Results come as each compound's % w/w plus total terpenes.
In practice
Because terpenes are volatile, sample handling dominates the result. Grinding warms the sample and releases volatiles; long shipping in warm conditions loses monoterpenes. A result of 2.1% total terpenes from fresh, carefully cured flower might read 1.4% after months of warm storage. Panels differ: one lab may include ocimene isomers, bisabolol and guaiol, another may not, so "total terpenes" isn't directly comparable between labs. Trace aroma drivers such as prenylated thiols are not on routine terpene panels.
Don't confuse with
Terpenes are volatile hydrocarbon compounds built from five-carbon isoprene units; in cannabis they are made in the trichome heads and are a major part of aroma and flavour.A monoterpene is a ten-carbon terpene made from geranyl pyrophosphate, such as myrcene, limonene, pinene or terpinolene; they are the most volatile terpenes and the first lost in drying.A sesquiterpene is a fifteen-carbon terpene made from farnesyl pyrophosphate, such as beta-caryophyllene, humulene and bisabolol; they are heavier and less volatile than monoterpenes.Beta-caryophyllene is a spicy, peppery sesquiterpene common in cannabis, notable as a dietary terpene that also binds the CB2 receptor in laboratory studies.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.Potency testing is laboratory measurement of a sample's cannabinoid content, normally by HPLC, reported as % w/w or mg/g for each cannabinoid plus calculated totals.A cannabinoid is any compound that binds the body's cannabinoid receptors or shares the typical cannabis terpenophenolic structure; the plant-made ones are phytocannabinoids such as THCA and CBDA.A residual solvents test measures leftover solvents such as butane, propane, ethanol or hexane in an extract, usually by headspace GC, against safety limits.A terpene profile is the measured mix of terpenes in a sample, reported as each compound's % w/w and the total, used to describe and compare cultivar aroma chemistry.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.Homogenisation is grinding and mixing a sample so every portion the lab tests represents the whole; together with representative sampling it often matters more than the instrument.
