Cannabis Potency Test Using the 630 FTIR Spectrometer

Importance of the Topic

The accurate determination of THC potency in cannabis products is critical for product labeling, quality assurance, and regulatory compliance. Rapid, reliable analytical methods support timely decision making in both industrial and clinical settings, and reduce reliance on time-consuming chromatography techniques.

Objectives and Overview

This study demonstrates the development of a multivariate calibration model using attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy to predict the potency of THC, THCA, and total THC in cannabis distillates and concentrates. The goal is to correlate FTIR spectral data with high-performance liquid chromatography (HPLC) reference measurements and evaluate model performance.

Methodology and Instrumentation

• Instrument: Agilent Cary 630 FTIR spectrometer equipped with a single-bounce diamond ATR module.
• Software: MicroLab PC for spectral acquisition and chemometric model development.
• Sample Preparation: Minimal handling of distillate and concentrate samples placed directly on the ATR crystal for measurement.
• Data Analysis: Multivariate chemometric calibration constructed to relate FTIR absorbance patterns to HPLC-measured potency values.

Main Results and Discussion

• High correlation coefficients were achieved between FTIR-predicted and HPLC-measured total THC values: R2 = 0.99 for distillate samples and R2 = 0.95 for concentrate samples.
• The model reliably quantified THC and THCA across a broad concentration range, demonstrating minimal bias and robust predictive performance.
• Real-time spectral acquisition enabled rapid potency estimates, with analysis time significantly shorter than traditional HPLC protocols.

Benefits and Practical Applications

• Significant reduction in analysis time compared to HPLC, enabling quick turnaround in quality control laboratories.
• Non-destructive measurement requiring no extensive sample preparation or solvent use.
• Cost-effective alternative for routine potency screening in regulated cannabis manufacturing and testing facilities.

Future Trends and Opportunities

• Extension of chemometric models to additional cannabinoids and terpene profiles for comprehensive compositional analysis.
• Integration of portable FTIR instruments for on-site testing at cultivation and processing facilities.
• Advances in cloud-based data sharing and machine learning algorithms to refine predictive accuracy and support remote monitoring.

Conclusion

The application of ATR-FTIR spectroscopy combined with multivariate calibration provides a rapid, accurate, and resource-efficient method for determining THC potency in cannabis distillates and concentrates. This approach offers a practical alternative to HPLC for routine quality control and helps streamline analytical workflows in the cannabis industry.