Forensic Authentication of Hemp-Derived Products Using a Dual Mass Spectrometry-UV Detection Approach

Significance of the Topic

Following the 2018 Farm Bill, hemp products containing less than 0.3% Δ9-THC became legal, driving rapid growth in the CBD market. However, some commercial offerings exceed the federal THC limit, raising compliance and enforcement challenges. Reliable, legally defensible analytical methods are essential for accurately quantifying THC and other cannabinoids in diverse hemp-derived matrices to protect consumers and support regulatory oversight.

Objectives and Study Overview

This study presents a unified workflow combining high-performance liquid chromatography with UV detection (HPLC-UV) and tandem mass spectrometry (MS/MS) on a SCIEX QTRAP 6500+ platform. The goal was to develop a single-dilution, single-injection approach capable of quantifying 11 cannabinoids across a wide potency range (0.05–100% by weight) in hemp flower and distillate samples.

Methodology and Instrumentation

• Sample Preparation: 0.2 g of homogenized flower or unhomogenized distillate was extracted with 10 mL acetonitrile, sonicated 30 min, centrifuged, filtered (0.2 µm), and diluted 1:100 (v/v) with acetonitrile.
• Chromatography: UHPLC on a Polar C18 column (150 × 4.6 mm, 3 µm) at 25 °C, 1 mL/min, 12.5 min run time, PDA detection at 210–230 nm.
• Mass Spectrometry: Scheduled MRM™ in both positive and negative modes on the SCIEX QTRAP 6500+.
• Data Processing: SCIEX OS Software 1.5 generated dual calibration curves (UV for high concentrations, MS/MS for low), calculated weight-percentages, and applied a molar correction factor (0.877×) for acid decarboxylation.

Main Results and Discussion

Calibration for Δ9-THC showed excellent linearity: MS/MS covered 0.05–5% (R² = 0.997) and UV covered 2.5–125% (R² = 0.999). Continuous calibration verifications yielded RSDs of 1.8% (0.5 ppm MS/MS) and 1.4% (25 ppm UV). Four hemp samples (three flowers, one distillate) were analyzed in a single run without method adjustments. Total THC in one flower sample was 0.15%, below the legal limit; other samples exceeded 0.3%.

Benefits and Practical Applications

• Single-dilution/injection scheme simplifies workflow and reduces analysis time.
• Dual detectors extend the linear dynamic range, capturing both trace and high-abundance cannabinoids.
• Automated flagging in SCIEX OS Software selects the optimal detector for each analyte, ensuring accurate quantitation.
• Custom reporting templates enable rapid generation of comprehensive potency reports.

Future Trends and Applications

Emerging directions include expanding target analyte libraries to novel cannabinoids, integrating automated sample preparation systems, deploying high-resolution MS for improved specificity, and leveraging cloud-based data analytics and AI for quality control, real-time compliance monitoring, and streamlined laboratory operations.

Conclusion

The combined HPLC-UV and MS/MS workflow on the SCIEX QTRAP 6500+ delivers a robust, versatile, and legally defensible method for forensic and quality assurance laboratories. It accurately quantifies a broad spectrum of cannabinoids in hemp-derived products in a single run, enhancing throughput and compliance confidence.

References

• 2018 Farm Bill, Section 12619.
• FDA Consumer Updates on Cannabis-Containing Products.
• SCIEX Technical Note RUO-MKT-02-9907-A: Potency Analysis in Hemp and Cannabis Products Using a Single-Dilution Combined LC-UV-MS/MS Approach.