Pesticides in Cannabis - A sample prep perspective

Importance of the Topic

Reliable detection of pesticide residues in cannabis products is essential to ensure consumer safety, regulatory compliance and product quality. Complex plant matrices rich in cannabinoids, terpenes and lipids can suppress analyte signals and complicate quantitation, making effective sample preparation a cornerstone of accurate pesticide analysis.

Objectives and Overview

This application note examines a tailored sample preparation workflow for pesticide testing in cannabis. It reviews common matrix interferences, compares cleanup techniques, and proposes a customized approach that balances efficiency, analyte recovery and instrument robustness using Agilent QuEChERS, SPE and dSPE products.

Methodology and Instrumentation

The workflow comprises:

• Solvent Extraction: Direct extraction of ground cannabis with acetonitrile (ACN) without water addition or salting out.
• SPE Cleanup: Use of SampliQ C18 EC cartridges to remove high‐abundance cannabinoids and nonpolar interferences.
• dSPE Post‐Treatment: Selective sorbents (PSA, C18, GCB) tailored for LC-MS/MS or GC-MS/MS to eliminate sugars, organic acids and pigments.
• Lipid Removal: Captiva EMR-Lipid cartridges employ size exclusion and hydrophobic interactions to trap triglycerides and phospholipids.
• Instrumentation: Analysis by LC-MS/MS on Agilent Ultivo Triple Quadrupole and other compatible platforms.

Main Results and Discussion

Key findings include:

• Matrix suppression by THC-A and other abundant cannabinoids was significantly reduced by C18 SPE, improving signal‐to‐noise ratios.
• QuEChERS dSPE provided broad cleanup but limited capacity for highly lipophilic or planar pesticides; addition of toluene or methanol modifiers mitigated sorbent co-extraction effects.
• Twenty-fold dilution further lowered matrix background, extended column lifetime and maintained >90% recovery for most target analytes.
• Captiva EMR-Lipid demonstrated superior removal of lipid components in high-fat edible matrices, preserving pesticide recovery and instrument uptime.

Benefits and Practical Applications

By integrating SPE and optimized dSPE, laboratories can achieve:

• Enhanced analyte recovery across diverse pesticide classes.
• Reduced instrument downtime due to matrix fouling.
• Scalable workflows adaptable to state-specific analyte lists and novel cannabis matrices such as edibles and tinctures.
• Cost‐effective cleanup using Agilent SampliQ and Captiva sorbents.

Future Trends and Opportunities

Ongoing developments are likely to include:

• Further customization of sorbent chemistries to address emerging pesticides and cannabinoids.
• Integration of automated SPE and online cleanup modules to streamline high-throughput testing.
• Expanded guidelines for edible, topical and inhalable cannabis products as regulations evolve.
• Advanced data analytics and background monitoring to predict maintenance intervals and optimize dilution strategies.

Conclusion

A combined SPE/dSPE approach, augmented by strategic dilution and lipid‐specific cleanup, delivers robust pesticide analysis in complex cannabis matrices. Adopting tailored sorbents and method adjustments enables reliable quantitation, regulatory compliance and improved laboratory efficiency.

References

• Hengel M. J. Expanded Method Development for the Determination of Pesticides in Dried Hops by Liquid Chromatography with Tandem Mass Spectrometry. Journal of the American Society of Brewing Chemists. 69(3):121–126, 2011.