ROUTINE ANALYSIS OF CANNABIS FOR PESTICIDES AND MYCOTOXINS USING UPLC-MS/MS

Importance of the Topic

The rapid expansion of medical and recreational cannabis use demands rigorous safety testing to protect consumer health and ensure product quality.
Pesticide residues and fungal toxins such as aflatoxins and ochratoxin A pose significant risks at trace levels, requiring sensitive and robust analytical workflows for regulatory compliance.

Objectives and Study Overview

This study presents a unified protocol for simultaneous determination of over 60 pesticides and five mycotoxins in cannabis flower.
The goal is to meet California action levels and other regulatory requirements using streamlined sample preparation and UPLC‐MS/MS and GC‐MS/MS analysis.

Methodology

Ground cannabis buds (0.5 g) are extracted with acetonitrile, homogenized using a Geno Grinder, and subjected to dispersive solid phase extraction cleanup with MgSO4, PSA, C18 and graphitized carbon.
Matrix matched calibration standards were prepared across relevant concentration ranges from 0.005 to 0.50 μg/kg for mycotoxins and 0.025 to 0.50 μg/kg for pesticides.

Used Instrumentation

• UPLC system: ACQUITY UPLC H-Class
• Column: XBridge C18 2.1×150 mm, 2.5 μm
• MS/MS detector: Xevo TQ-S micro with ESI positive and negative modes
• Software: Quanpedia for automated LC, GC and data processing method generation

Key Results and Discussion

All analytes exhibited excellent linearity (R2>0.99) over the tested ranges.
Method recoveries for the majority of compounds were between 80 and 120 at spiked levels of 0.1 and 0.5 μg/kg.
Dispersive SPE cleanup markedly reduced matrix suppression, particularly for analytes coeluting with resin components.
Representative MRM chromatograms confirmed trace level detection of aflatoxins B1, B2, G1, G2 and ochratoxin A at 0.02 μg/kg.

Benefits and Practical Applications

The integrated workflow substantially lowers method development time through software automation and pre-defined LC-MS/MS and GC-MS/MS protocols.
Single-injection analysis of pesticides and mycotoxins improves laboratory efficiency and throughput.
High sensitivity and robust cleanup support reliable QA/QC testing for cultivators and regulators.

Future Trends and Applications

Continuous expansion of target analyte libraries via intelligent software updates to address emerging pesticide and mycotoxin lists.
Adoption of high resolution mass spectrometry and automated online sample preparation for higher throughput and broader screening scope.
Potential extension to other botanical matrices and development of field-deployable testing platforms for rapid on-site monitoring.

Conclusion

The presented protocol combining acetonitrile extraction, dispersive SPE cleanup and automated UPLC‐MS/MS and GC‐MS/MS method generation offers a rapid, sensitive and robust solution for routine multi-residue analysis of pesticides and mycotoxins in cannabis, fulfilling strict regulatory requirements.

References

1. Tran K Organtini K Twohig M Alden P Young MS Meruva N Rosnack K Fujimoto G Stevens R Roush J Hudalla CJ Analysis of Residual Pesticides and Mycotoxins in Cannabis Using UPLC MS MS and GC MS MS to Meet California Regulatory Requirements Waters Application Note 720006465EN 2019