Analysis of Terpenes in Cannabis with Hydrogen Carrier Gas and the Agilent HydroInert Source on the Agilent Intuvo 9000/5977C GC/MS

Significance of the Topic

Gas chromatography/mass spectrometry (GC/MS) is crucial for profiling terpenes in cannabis, which underpin strain-specific aromas and flavors. Shifting from helium to hydrogen carrier gas addresses supply constraints, cost pressures and sustainability goals, while maintaining analytical rigor.

Objectives and Study Overview

This study evaluates the performance of the Agilent Intuvo 9000 GC coupled to a 5977C single quadrupole MS equipped with the HydroInert electron ionization source. The method aims to resolve and quantify 40 terpenes using hydrogen carrier gas, comparing results to established helium-based protocols.

Methodology and Instrumentation

A split injection of 1 µL was performed on DB-Select 624, 20 m × 0.18 mm, 1.0 µm columns with hydrogen flow rates of 0.60–0.75 mL/min. The HydroInert source with a 9 mm extractor lens mitigated hydrogen’s reactivity in EI ionization. Quantitation employed selective ion monitoring (SIM) for characteristic ions across 20 time segments. Calibration used eight concentration levels (3.83–490.20 µg/mL) and internal standard (2-fluorobiphenyl).

Main Results and Discussion

The hydrogen-based method delivered an elution profile analogous to helium with a reduced runtime of 23 min versus 30 min. Calibration curves exhibited excellent linearity (R2 ≥ 0.996), limits of detection between 0.07–0.58 µg/mL, and limits of quantitation below 1.64 µg/mL. Accuracy ranged from 86.0 to 119.0% and precision (%RSD) under 3.9% at three concentration levels. Analysis of six cannabis flower samples revealed distinct terpene patterns and reproducible quantitation (%RSD < 10.5%).

Benefits and Practical Applications

The validated approach enables laboratories to switch to hydrogen without compromising sensitivity, accuracy or throughput. Reduced run times increase sample throughput and hydrogen’s sustainability profile can lower operating costs and environmental impact. The HydroInert source safeguards against artifact formation.

Applied Instrumentation

• Agilent Intuvo 9000 GC with split/splitless inlet
• DB-Select 624 columns (20 m × 0.18 mm, 1.0 µm)
• Agilent HydroInert EI source, 9 mm extractor lens
• Agilent 5977C MSD in SIM mode

Future Trends and Potential Applications

Ongoing improvements may focus on further runtime optimization, expansion to additional volatile compounds, and integration with automated sample preparation. Hydrogen-based GC/MS methods are poised to support broader compliance testing and routine quality control in commercial cannabis products.

Conclusion

Transitioning to a hydrogen carrier gas with the Agilent HydroInert source enables robust, fast and accurate terpene profiling in cannabis comparable to helium-based systems. This approach addresses resource constraints and enhances laboratory sustainability.

References

1. Agilent Inert Plus GC/MS System with HydroInert Source, Tech. Overview 5994-4889EN (2022)
2. Helium to Hydrogen Carrier Gas Conversion Guide, User Guide 5994-2312EN (2022)
3. Agilent GC/MS Hydrogen Safety Manual G7006-90053 (2022)
4. Hollis et al., Application Note 5994-2032EN (2020)
5. Fully Automated Terpene Sample Prep, Application Note 5994-6007EN (2023)