Qualitative and quantitative determination of cannabinoid profiles and potency in CBD hemp oil using LC/UV and Mass Selective Detection

Importance of the Topic

As legal frameworks expand for medicinal and recreational Cannabis sativa, accurate profiling of cannabinoid content in hemp-derived products is essential for safety, potency labeling, and regulatory compliance.

Objectives and Study Overview

This study demonstrates a fast and reliable analytical approach using an Agilent 1290 Infinity II UHPLC coupled with a single quadrupole Mass Selective Detector (MSD) to qualitatively and quantitatively analyze ten key cannabinoids—including Δ9-THC and Δ9-THCA—in commercial CBD hemp oil samples.

Experimental Methodology

• Sample Preparation: Automated dilution of commercially available hemp oil samples to ensure consistency and reproducibility.
• Chromatographic Conditions: Agilent ZORBAX Poroshell Bonus RP column (3.0 × 50 mm, 2.7 µm) at 50 °C with a 6.25-minute gradient cycle; mobile phases of water, methanol, and acidic water/ammonium formate; 0.5 µL injection volume.
• UV Detection: Diode array detection (DAD) at 230 nm for initial quantitation; calibration curves prepared over 0.05–100 µg/mL with R² ≥ 0.999.
• Mass Spectrometry: Agilent MSD in positive ESI mode; nitrogen nebulizer (30 psi) and drying gas (5 L/min at 350 °C); SIM monitoring of characteristic ions (e.g., 315.2, 287.0, 311.0 m/z).
• Replicate Analysis: Sixfold replicates (n = 6) to assess precision and reproducibility.

Instrumental Setup

• UHPLC: Quaternary pump, multisampler with wash, multicolumn thermostat.
• Column: ZORBAX Poroshell Bonus RP, 3.0 × 50 mm, 2.7 µm.
• MSD: Single quadrupole with multimode ion source enabling simultaneous ESI and APCI.
• Software: Agilent OpenLAB CDS for data acquisition and quantitative analysis.

Main Results and Discussion

The UHPLC-UV/MSD method achieved baseline separation of all ten cannabinoids in under five minutes. Calibration curves exhibited excellent linearity (R² ≥ 0.9992) and limits of quantitation down to 1 ng/mL. SIM overlays confirmed unambiguous identification, and retention-time alignment with a spectral library—including Δ8-THC—enabled detection of trace isomers.

Analysis of a hemp oil blank and six CBD products revealed CBD concentrations matching label claims (8–25 mg/mL), low Δ9-THC levels (<0.12 mg/mL), detectable CBDA in all commercial samples, and CBG in selected oils. These findings underscore the method’s suitability for both potency assessment and quality control.

Benefits and Practical Applications

This workflow provides laboratories with a high-throughput, robust platform for routine screening of cannabinoids in hemp and cannabis products. Combining UV quantitation with mass-selective confirmation enhances confidence in results, supporting compliance testing, product labeling, and safety evaluations.

Future Trends and Applications

Emerging directions include integration with high-resolution mass spectrometry for non-targeted screening, miniaturized and field-deployable systems for on-site analysis, and expanded profiling of minor and novel cannabinoids to meet evolving regulatory and research needs.

Conclusion

The described Agilent UHPLC-UV/MSD method delivers rapid, precise, and unequivocal analysis of major cannabinoids in hemp oil. Its reproducible performance and comprehensive detection capabilities make it an effective tool for potency determination, quality assurance, and regulatory compliance.

References

1. Huestis MA Human Cannabinoid Pharmacokinetics. Chem Biodivers. 2007;4(8):1770–1804.