"Skunky" Cannabis: Environmental Odor Troubleshooting and the "Need-for-Speed"

Area of Science:

• Agricultural Chemistry
• Analytical Chemistry
• Organic Chemistry

Background:

• The characteristic "skunky" odor of cannabis and industrial hemp has been historically misattributed to general "skunky terpenes".
• Recent scientific reports have identified a specific volatile sulfur compound as the primary source of this distinct aroma.

Purpose of the Study:

• To clarify the historical misattribution of the "skunky" odorant in cannabis and industrial hemp.
• To highlight the investigative strategy and methodology used to identify 3-methyl-2-butene-1-thiol (321MBT) as the key odorant.

Main Methods:

• Utilized rapid multidimensional-gas chromatography-mass spectrometry-olfactometry (MDGC-MS-O).
• Employed an odorant-prioritization "screening" approach to isolate and identify key volatile compounds.
• Correlated analytical findings with sensory analysis to confirm odorant identity.

Main Results:

• Confirmed 3-methyl-2-butene-1-thiol (321MBT) as the primary odorant responsible for the "skunky" aroma in cannabis and industrial hemp.
• Established the timeline of public disclosure, indicating earlier findings by the Koziel team compared to the Oswald team regarding the 321MBT link.

Conclusions:

• The "skunky" aroma is definitively linked to 3-methyl-2-butene-1-thiol (321MBT).
• The Koziel team's rapid MDGC-MS-O approach was instrumental in the early identification and public disclosure of this odorant.