Terpenes Analysis in Cannabis Products by Liquid Injection using the Agilent Intuvo 9000/5977B GC/MS System

Importance of the topic

Terpenes are key volatile and semi-volatile compounds responsible for the flavor, aroma, and therapeutic properties of cannabis. Reliable terpene profiling is critical for strain characterization, quality control, and product labeling in both medicinal and recreational cannabis programs. Traditional headspace GC methods may under-report certain sesquiterpenes in high-potency samples, driving the need for a robust liquid injection GC/MS approach.

Objectives and overview of the study

The aim was to develop and validate a sensitive, selective, and reproducible liquid injection GC/MS method for the quantitative analysis of 40 common cannabis terpenes. The study evaluated method performance in terms of calibration range, linearity, accuracy, precision, detection limits, and applicability to commercial products.

Methodology and instrumentation

Samples and calibrators were prepared in a hempseed oil matrix with 2-fluorobiphenyl as an internal standard. A seven-point calibration over ~4–485 µg/mL (0.0004–0.05% wt/wt) was performed in quintuplicate. Limits of detection (LOD) and quantitation (LOQ) were calculated statistically (MDL with Student’s t, LOQ = 10×SD). Accuracy (>80%–120%) and precision (%RSD < 15%) criteria were applied.

Used Instrumentation

• Agilent Intuvo 9000 GC with capillary flow backflush and multimode inlet (or optional split/splitless inlet)
• Agilent 7650A 50-position liquid autosampler (10 µL syringe)
• DB-Select 624 Ultra Inert columns (30 m × 0.25 mm ID, 1.4 µm)
• Agilent 5977B MSD with EI Extractor source and SIM/Scan acquisition
• Agilent MassHunter B.10 Acquisition and Quantitative Analysis software

Major results and discussion

Calibration curves (1/x weighting) exhibited coefficients of determination (R²) > 0.99 for all 40 terpenes. Intraday and interday precision (%RSD) were generally < 7%, with most values < 5%. MDLs ranged from ~0.0004 to 0.009 % wt/wt; LOQs from ~0.0015 to 0.03 % wt/wt. Accuracy across three batches met acceptance criteria for > 90% of analytes. The internal standard showed stable response (RSD 3–6%). Application to a commercial terpene blend revealed deviations from label claims: α-humulene and limonene were lower than claimed, whereas myrcene was higher. The SIM/Scan approach also enabled detection of minor terpenes not specified by the vendor.

Benefits and practical applications of the method

This liquid injection GC/MS workflow offers enhanced sensitivity, selectivity, and robustness compared to headspace methods, reducing losses of high-molecular-weight terpenes. It is well suited for regulatory and quality control laboratories analyzing complex cannabis matrices and can be adapted for routine strain verification, label compliance, and research studies.

Future trends and opportunities

Advances may include chiral separation of terpene enantiomers to resolve stereoisomers, coupling to high-resolution MS for unknown identification, and fully automated sample preparation. Emerging needs include comprehensive profiling of minor terpenes, integration with data-rich informatics platforms, and application to novel cannabinoid-rich matrices.

Conclusion

A reliable, validated liquid injection GC/MS method has been established for quantitative analysis of 40 cannabis terpenes. The approach meets stringent performance criteria and addresses limitations of headspace analysis, offering a valuable tool for the cannabis industry.

References

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