Chemical Profiling of Cannabis Infused Products using Solvent-Free Headspace Extraction and Thermal Desorption GC-MS

Significance of the Topic

Recent growth in both recreational and medical cannabis use has driven demand for robust analytical methods to characterize cannabinoids, terpenes and additives in plant material and infused products. Solvent-free headspace extraction paired with thermal desorption GC-MS addresses environmental and safety concerns while delivering sensitive profiling of volatile and semi-volatile compounds. This approach supports quality control, product development and regulatory compliance within the cannabis industry.

Objectives and Study Overview

The primary goal of this work is to demonstrate a vacuum assisted sorbent extraction (VASE) technique combined with thermal desorption GC-MS for chemical profiling of raw cannabis and infused edibles. The study examines method performance for detecting cannabinoids, residual solvents, flavor compounds and strain-dependent terpene profiles across various sample types including flowers, gummies, chocolates and beverages.

Methodology and Used Instrumentation

The workflow consists of six steps:

• Sample homogenization and vial evacuation using a two-stage diaphragm pump to promote headspace enrichment of target analytes.
• Diffusive headspace extraction under vacuum and controlled heating, capturing volatiles on a Headspace Sorbent Pen (HSP).
• Water management by chilling vials to condense moisture and protect the sorbent bed.
• Direct thermal desorption of Sorbent Pens into a GC-MS via a Sorbent Pen Thermal Desorption Unit (SPDU) and Sample Preparation Rail (SPR).
• Analysis by capillary GC-MS with optimization of desorption temperature, preheat and bake-out parameters to maximize recovery and minimize carryover.
• Clean pen storage allowing reuse or reconditioning of sorbent pens for up to one month.

Key instrumentation includes:

• Sorbent Pen Technology with Micro-QT septum-less seal and multiple sorbent options (Tenax TA, Carboxen, Carbopack).
• Sorbent Pen Thermal Desorption Unit (SPDU) and Thermal Conditioner (SPTC).
• Sample Preparation Rail (SPR) for automated pen handling atop a GC-MS system.

Main Results and Discussion

Application of VASE-TD-GC-MS to ~5 mg cannabis flower shows that both heat and vacuum are critical for efficient extraction of THC and other cannabinoids. Comparative profiles of five strains reveal distinct monoterpene and sesquiterpene fingerprints, highlighting chemotype differences. Analysis of infused products (130 mg espresso crunch, 140 mg fruit bites, 2 µL CBD mango solution) successfully detected residual solvents, flavor additives such as vanillin, and cannabinoid content without solvent extraction, demonstrating method versatility across matrices.

Benefits and Practical Applications

• Solvent-free extraction reduces sample preparation time, costs and solvent waste.
• High sensitivity for cannabinoids, terpenes and trace additives supports quality control and batch consistency.
• Reusable sorbent pens and minimal carryover improve throughput and lower operating expenses.
• Non-destructive sampling of low-mass samples enables analysis of scarce or high-value materials.

Future Trends and Applications

Advancements may include integration with high-resolution mass spectrometry for untargeted profiling, expanded sorbent chemistries for enhanced selectivity, and full automation of pen handling for high-throughput laboratories. The technique holds promise for environmental monitoring of cannabis emissions, personal exposure studies and broader applications in food flavor and fragrance analysis.

Conclusion

The VASE technique coupled with thermal desorption GC-MS delivers a powerful solvent-free approach for comprehensive chemical profiling of cannabis and infused products. Through optimized vacuum-assisted headspace extraction and robust desorption protocols, the method achieves sensitive detection of cannabinoids, terpenes and additives across diverse sample types, supporting industry needs for quality assurance and regulatory compliance.