SPME Arrow Sampling of Terpenes in Cannabis Plant Material

Importance of the Topic

Medicinal cannabis legalization drives demand for rapid, reliable terpene analysis to assure quality, potency and flavor consistency. Headspace solid-phase microextraction (SPME) Arrow methods enable volatile profile characterization with minimal sample prep and no solvents.

Study Objectives and Overview

This study evaluates qualitative profiling and quantitative determination of cannabis terpenes using SPME Arrow sampling combined with GC/MS. It compares two fiber phases and measures linearity, sensitivity and reproducibility across multiple plant samples.

Methodology

• Qualitative profiling: 0.02–0.03 g homogenized flower in 20 mL vial, 120 µm DVB/CAR/PDMS Arrow, headspace sampling.
• Quantitative analysis: 0.1 g sample, 100 µm PDMS Arrow, calibration 2–50 ppm, addition of water, equilibration 10 min at ambient temperature.
• SPME conditions: 5 min incubation at 40 °C with agitation, 5 min extraction, 3 min desorption, 5 min conditioning of fiber.
• GC/MS: Agilent 7890B GC with 5977B MSD, DB-1ms column (60 m, 0.25 mm, 0.25 µm), oven: 60 °C (2 min)→140 °C at 5 °C/min (1 min)→250 °C at 15 °C/min (4 min); MS in scan mode.

Instrumentation

• PAL RTC autosampler with SPME Arrow modules.
• Agilent 7697A headspace unit, 7890B GC, 5977B MSD.
• SPME Arrows: 120 µm DVB/CAR/PDMS (p/n 5191-5861), 100 µm PDMS (p/n 5191-5862).
• DB-1ms GC column (p/n 122-0162).

Main Results and Discussion

Both fiber phases yielded clear profiles for key terpenes across diverse cannabis samples. Calibration curves for major compounds (e.g., α-pinene, myrcene, terpinolene) showed excellent linearity (R² > 0.995). The PDMS Arrow reduced overload effects and provided robust quantitation with reproducible retention times. Sample data demonstrated significant variation in terpene concentrations between cultivars.

Benefits and Practical Applications of the Method

• Solvent-free extraction avoids matrix interferences and reduces costs.
• High sensitivity and robustness enable both qualitative fingerprinting and quantitative assays.
• Rapid sampling and analysis support high throughput in QC and research labs.
• Spectral data facilitate confident compound identification.

Future Trends and Potential Applications

Integration of SPME Arrow with automated workflows and advanced MS detectors can further streamline terpene analysis. Emerging applications include real-time process monitoring, counterfeit detection and linking terpene profiles to therapeutic outcomes.

Conclusion

SPME Arrow sampling coupled with GC/MS delivers a fast, reliable approach for terpene profiling in cannabis. The method offers solvent-free operation, strong linearity and high reproducibility, making it suitable for diverse analytical needs in the cannabis industry.

References

1. Agilent Technologies. Analysis of Terpenes in Cannabis Using the Agilent 7697A/7890B/5977B Headspace GC-MSD System. Application Note 5991-8499EN, September 2017.
2. Stenerson K., Halpenny M. Analysis of Terpenes in Cannabis Using Headspace Solid-Phase Microextraction and GC–MS. LCGC, May 1 2019.