CHARACTERIZATION OF DELTA-8 THC DISTILLATES USING HIGH RESOLUTION MASS SPECTROMETRY (HRMS)

Importance of the Topic

Delta-8 tetrahydrocannabinol (Δ8-THC) is increasingly used in consumer products, raising safety and regulatory concerns. Unlike the main psychoactive isomer Δ9-THC, Δ8-THC occurs at low levels in hemp and is often produced by chemical conversion of CBD. This process generates multiple byproducts whose identity, abundance, and potential toxicology remain largely uncharacterized. Developing robust analytical methods to profile these distillates is critical for quality control, consumer safety, and regulatory compliance.

Objectives and Study Overview

This work aimed to apply high-resolution mass spectrometry combined with UHPLC-PDA to comprehensively characterize Δ8-THC distillates. Key goals included:

• Detect and identify known cannabinoids and conversion byproducts
• Quantify relative abundances using UV and MS data
• Evaluate structural relationships of unknown components via MS/MS fragmentation

Methodology and Data Processing

Distillate samples were diluted in acetonitrile and analyzed by UHPLC-PDA (210–400 nm) in conjunction with a Xevo G3 QToF mass spectrometer operating in data-independent (MSE) mode. Low- and high-collision energy spectra were acquired simultaneously. A proprietary compound library containing accurate masses, retention times, isotope patterns, and fragment ion information was used for putative identification. Structural elucidation tools within the UNIFI software facilitated assignment of unknowns.

Used Instrumentation

• ACQUITY UPLC I-Class Plus system with CORTECS C18 column (2.1 × 100 mm, 1.6 μm)
• Xevo G3 QToF with ESI+ (capillary 1.0 kV; cone 15 V; source 100 °C; desolvation 450 °C)
• UNIFI Scientific Information Software for data acquisition and processing
• Gradient elution with 0.1% formic acid in water (A) and acetonitrile (B), flow rate 0.56 mL/min

Main Results and Discussion

Analyses of two Δ8-THC distillate batches revealed:

• Clear detection of Δ8-THC, Δ9-THC, exo-THC, CBL, CBC, and other known cannabinoids via PDA and QToF MS
• Multiple unknown peaks with a base peak at m/z 315.2319 corresponding to C21H30O2, eluting adjacent to Δ8-THC; UV area percentages ranged from 0.13 to 4.9%
• MS/MS fragmentation patterns matched those of Δ9-THC isomers, suggesting structural variants or isomers
• In sample B, Δ8-THC purity was ~79%, with an unknown component at 19.4% (tR 3.10 min)
• Discovery of a chlorinated unknown (m/z 351.2080, C21H31ClO2) with isotopic pattern and fragments indicating a mono-chlorinated THC derivative

Benefits and Practical Applications

The approach offers:

• Comprehensive profiling of Δ8-THC distillates for QA/QC and regulatory testing
• Identification of potentially bioactive or toxic byproducts requiring further study
• Data to inform manufacturing practices and improve product safety

Future Trends and Opportunities

Advancements are expected in:

• Expanded high-resolution libraries of synthetic cannabinoid analogues
• Standardization of reference materials for unknown isomers and halogenated derivatives
• Integration of orthogonal techniques (ion mobility, NMR) for definitive structure confirmation
• Regulatory guidelines addressing synthetic cannabinoid impurities in hemp-derived products

Conclusion

UHPLC-PDA coupled with QToF MSE effectively profiles Δ8-THC distillates, detecting both known cannabinoids and novel byproducts, including chlorinated derivatives. The workflow demonstrates the importance of high-resolution MS for ensuring product quality, consumer safety, and guiding regulatory frameworks.

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