Quantification of THC and CBD in Gummies and Hard Candies

Importance of the Topic

Accurate quantification of Δ9-tetrahydrocannabinol (Δ9-THC) and cannabidiol (CBD) in sugar-rich edibles such as gummies and hard candies is critical for consumer safety, regulatory compliance and proper product labeling. The complex matrices, variable formulations (gelatin, pectin, corn starch) and sticky, high-sugar content challenge conventional sample preparation and extraction approaches, often limiting laboratory throughput and analytical robustness.

Objectives and Overview

This study demonstrates a streamlined, high-throughput workflow to:

• Process gummies and hard candies without cryo-milling
• Optimize extraction for complete dissolution and efficient analyte partitioning
• Quantify THC and CBD by liquid chromatography with UV detection (LC/UV)
• Validate performance in terms of accuracy, precision, linearity and sample cleanliness

Methodology and Instrumentation

Samples were precisely weighed (1.00 g), interior portions isolated, then homogenized with water and disposable ceramic beads in a mechanical shaker. Alkaline QuEChERS extraction was performed by adding acetonitrile containing 2 % ammonia and extraction salts. After agitation and centrifugation, the top acetonitrile layer was filtered through a 0.2 µm PTFE membrane prior to analysis. Method performance was assessed by matrix-matched calibration (0.5–200 µg/mL), recovery experiments and commercial sample testing.

Instrumentation Used

• Agilent 1260 Infinity II LC System with Flexible Pump, Vialsampler and DAD at 230 nm
• Poroshell 120 EC-C18 column, 3.0 × 150 mm, 2.7 µm (with guard column)
• Mechanical homogenizer (1,500 rpm) and centrifuge (3,600 rpm)
• Agilent EU QuEChERS extraction kit and PTFE syringe filters
• Optional Agilent 6545 LC/Q-TOF for qualitative matrix evaluation

Main Results and Discussion

High-pH extraction consistently enhanced THC and CBD signal by LC/UV compared to neutral or acidic conditions. Polar interferences (sugars, starch) remained in the aqueous phase of QuEChERS, yielding cleaner acetonitrile extracts. Method performance in gelatin and pectin gummies showed:

• Linearity over 0.5–200 µg/mL with R² ≥ 0.9998
• Recovery efficiencies of 92–94 % for both CBD and THC
• Interday precision < 4 % RSD and accuracy within ±8 %
• Accuracy in commercial samples at 107 % of label claim

Benefits and Practical Applications

This protocol reduces sample preparation time by eliminating cryo-milling, increases throughput, and is robust across diverse candy formulations. It ensures reliable potency testing for quality control laboratories, supports regulatory compliance and can be extended to screen up to 17 cannabinoids.

Future Trends and Applications

Advancements may include integration with LC/MS/MS for confirmation of minor cannabinoids, development of automated sample-to-report platforms, expansion of lipid removal strategies for whole-gummy analysis, and adaptation to emerging edible formats. Harmonization of regulatory standards will drive demand for lower detection limits and broader analyte panels.

Conclusion

The described alkaline QuEChERS–LC/UV workflow offers a fast, simple and reproducible solution for quantifying THC and CBD in gummies and hard candies, overcoming matrix challenges and enhancing laboratory productivity.

References

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