Analysis of Residual Solvents in Cannabinoid Products with Hydrogen Carrier Gas and the Agilent HydroInert Source

Importance of the Topic

Residual solvents analysis is essential to ensure cannabis and hemp–derived products comply with stringent health and safety regulations. Trace amounts of volatile organic compounds must be accurately quantified to protect consumers and meet legal limits. Transitioning from helium to hydrogen as the carrier gas addresses global helium shortages, reduces operational costs, and can accelerate chromatographic separations without compromising data quality.

Objectives and Study Overview

This study aimed to adapt a published helium-based GC/MS residual solvents method for hydrogen carrier gas and to evaluate its performance using a single-quadrupole system in selected ion monitoring (SIM) mode. Key goals included reducing analysis time, maintaining or improving method sensitivity, and verifying spectral fidelity when using an Agilent HydroInert ion source.

Methodology and Instrumentation

Sample preparation followed a modified headspace protocol: 1.0 g of cannabis matrix was spiked with known levels of a residual solvents standard and α,α,α-trifluorotoluene internal standard. An eleven-point, matrix-matched calibration (0.49–1000 µg/g) was constructed, and method detection limits were determined via six replicate injections. Quantitation employed quadratic fits with 1/x weighting.

Used Instrumentation

• Agilent 8697 Headspace Sampler with 0.50 mL inert loop and side-mount XLSI adapter
• Agilent Intuvo 9000 GC fitted with dual 20 m × 0.18 mm DB-Select 624 columns
• Agilent 5977C MSD equipped with HydroInert source (9 mm extractor lens)
• Standard headspace vials, syringes, septa, inlet liners, and guard chips as per Agilent consumables list

Main Findings and Discussion

Switching to hydrogen reduced total run time from 13 min to 9 min while preserving an elution profile comparable to helium. Calibration curves for 31 analytes exhibited correlation coefficients (R²) > 0.995. Limits of detection (LOD) and quantification (LOQ) ranged from 0.12–11.73 µg/g and 0.39–39.09 µg/g, respectively, and remained below regulatory thresholds. Accuracy spanned 92.0–111.0 % and precision 1.0–9.9 % RSD. Library match scores against NIST 23 exceeded 94.4 % for hydrogen-generated spectra, confirming minimal redox reactions in the HydroInert source. Matrix effects varied among analytes, with lighter non-polar solvents showing slight enhancement and heavier or polar compounds experiencing up to 98 % suppression.

Benefits and Practical Applications

• Reduced run time and increased throughput
• Lower carrier gas costs and relief from helium shortages
• High sensitivity and compliance with state regulations
• Reliable compound identification via preserved spectral fidelity

Future Trends and Opportunities

Expansion of hydrogen-based GC/MS methods to broader solvent panels, diverse cannabis matrices, and multi-analyte screening is expected. Advances in inert source technologies and data deconvolution tools will further enhance method robustness. Environmental and cost benefits of hydrogen usage may drive wider adoption in analytical laboratories.

Conclusion

The hydrogen-carrier GC/MS method with an Agilent HydroInert source delivers rapid, accurate, and precise residual solvents analysis in cannabinoid products. It matches or exceeds helium-based performance, ensures spectral integrity, and supports high-throughput, compliant testing.

References

1. Harper T., Hollis J.S., Macherone A. Novel Residual Solvents Analysis of Cannabinoid Products with the Agilent Headspace-GC/MS System. Agilent Technologies Application Note 5994-1926EN, 2020.
2. Agilent Inert Plus GC/MS System with HydroInert Source. Agilent Technologies Technical Overview 5994-4889EN, 2022.
3. Agilent EI GC/MS Instrument Helium to Hydrogen Carrier Gas Conversion. Agilent Technologies User Guide 5994-2312EN, 2022.
4. Agilent GC/MS Hydrogen Safety. Agilent Technologies User Guide G7006-90053, 2022.
5. Hydrogen Safety for the Agilent 8890 GC System. Agilent Technologies Technical Overview 5994-5413EN, 2022.
6. Haddad S.P., Patel S.U., Westland J.L. Analysis of Terpenes in Cannabis with Hydrogen Carrier Gas and the Agilent HydroInert Source on the Agilent Intuvo 9000/5977C GC/MS. Agilent Application Note 5994-6216EN, 2023.
7. Agilent Custom GC Columns Shop, Agilent Technologies.