Cannabinoid & Terpene Profiling of Cannabis by Solvent-Free Headspace Extraction and Thermal Desorption-GC-MS

Significance of the Topic

Comprehensive analysis of cannabinoids and terpenes in cannabis is vital for quality control, regulatory compliance, and research into therapeutic effects. The synergistic interactions between these compounds, known as the entourage effect, underscore the need for rapid and reliable profiling methods.

Objectives and Study Overview

This study aims to demonstrate a solvent-free headspace extraction technique, vacuum assisted sorbent extraction (VASE), coupled with thermal desorption gas chromatography–mass spectrometry (TD-GC-MS) for simultaneous quantification of cannabinoids and terpenes in cannabis flower. The approach targets a total analysis time of under one hour from raw material to data output.

Methodology

VASE relies on a sorbent pen system to capture volatile and semi-volatile compounds directly from homogenized plant material under vacuum. Key procedural steps include:

• Sample homogenization (≥0.5 g, 5 min)
• Vacuum headspace extraction with flash heating (5 min)
• Thermal desorption sequence: 30 s at 70 °C preheat, 6 min at 225 °C desorption, 22 min at 300 °C bakeout

Dual-column TD-GC-MS enables separation of terpenes (unretained on column 1) and cannabinoids (initially retained on column 1 and released splitlessly to column 2) in a single run.

Instrumentation

The following components were employed:

• Vacuum assisted sorbent extraction system with Micro-QT septum-less seal and Silonite™-coated surfaces
• Sorbent pens packed with Tenax TA, Carboxen, and Carbopack variants
• Thermal desorption unit optimized for TRACE Analysis conditions
• GC-MS: Agilent 7890A gas chromatograph coupled to 5975C mass spectrometer; Quadrex UAC-1MS/HT precolumn (1.5 m×0.53 mm×0.25 µm) and Agilent DB-5MS analytical column (30 m×0.25 mm×0.5 µm)

Main Results and Discussion

The method achieved chemical profiles for monoterpenes, sesquiterpenes, and cannabinoids with extraction times under 10 minutes and a total cycle time below one hour. Reproducibility studies demonstrated consistent peak areas across multiple sorbent pens and sample runs. Distinct terpene and cannabinoid fingerprints were generated for different cannabis strains, highlighting the technique’s analytical precision and sensitivity.

Practical Benefits and Applications

This solvent-free, rapid approach offers several advantages:

• Reduced sample preparation and solvent costs
• High throughput suitable for routine quality control and regulatory testing
• Comprehensive profiling in a single analytical sequence
• Potential for quantitative method development and comparative chemotyping

Future Trends and Applications

Advancements may include integration with automated sample handling, expansion of sorbent chemistries for a broader analyte range, and coupling with high-resolution mass spectrometry for trace-level detection. The platform could be adapted for other complex botanicals and environmental monitoring of volatiles.

Conclusion

The combination of VASE and dual-column TD-GC-MS provides a fast, reliable, and solvent-free solution for simultaneous terpene and cannabinoid analysis in cannabis flower. The method’s reproducibility and efficiency make it a valuable tool for research, quality assurance, and product development.

References

Russo EB (2011) Taming THC: potential cannabis synergy and phytocannabinoid-terpenoid entourage effects. British Journal of Pharmacology 163(7):1344–1361