Identification of Key Sensory-Active Compounds in Cannabis by Aroma Dilution Analysis

Cannabis is an exponentially growing market as legalization continues worldwide. Selective breeding creates strains with various scents to meet consumer demands and preferences. The scents can be attributed to the volatile secondary metabolites, which are often present at very low concentrations. High-capacity extraction techniques, coupled with gas chromatography-olfactometry/mass spectrometry (GC-O/MS), enable the separation and identification of low-concentration, sensory-active compounds in complex sample matrices with minimal sample preparation time. In this study, the GC-O method, aroma dilution analysis (ADA), a solvent-free approach to aroma extract dilution analysis (AEDA), is used to determine the odor potency of sensory-active compounds in cannabis.

In this study, Dynamic Headspace (DHS) was used to extract sensory-active compounds from cannabis. DHS is an automated, solventless means of extracting analytes. The DHS extraction technique purges the headspace above a sample and concentrates the volatiles onto a sorbent-filled trap. Because DHS is a non-equilibrium technique, more volatiles are driven into the headspace, resulting in improved recovery and extremely low detection limits. Selectable 1D/2D-GC-O/MS or “heart-cutting” GC was used to resolve components in the complex matrix. The system is configured with two low thermal mass (LTM) GC columns featuring dissimilar column phases and a valveless, software-controlled column switching device, allowing for easy implementation of a 2D GC separation. Combining these techniques in an SDA approach with ADA enabled the identification of key sensory-active compounds in cannabis.