Multi-elem ent Analys is of Cannabis us ing the Agilent 7800 ICP-MS

Importance of the Topic

Cannabis products for medicinal and recreational use must be rigorously tested for toxic and essential elements to guarantee consumer safety. Inorganic contaminants such as As, Cd, Pb, and Hg pose health risks, while mineral profiling supports nutritional labeling. Robust multi-element analysis throughout production prevents contamination and ensures regulatory compliance.

Objectives and Study Overview

This study demonstrates a comprehensive method for quantifying 25 elements in cannabis plant materials and related products using the Agilent 7800 ICP-MS. It evaluates sample preparation, calibration strategies, interference correction, and method performance on real samples and certified reference materials.

Methodology and Instrumentation

• Sample Preparation: Microwave-assisted acid digestion with HNO3/HCl followed by 5× dilution to reduce acidity.
• Instrument: Agilent 7800 ICP-MS with High Matrix Introduction (HMI), Micromist nebulizer, quartz spray chamber, and nickel-plated cones.
• Software Features: Automated half-mass correction for doubly charged rare earth interferences and Quick Scan for semiquantitative full mass-range data.
• Calibration: Multi-level calibration (0.5–100 ppb for trace elements, 0.05–2 ppb for Hg, 0.5–10 ppm for major elements) and continuous calibration verification (CCV).
• Quality Control: Use of NIST SRMs (Peach Leaves, Tomato Leaves, Pine Needles, Natural Water) for spike recovery and method validation.

Main Results and Discussion

• Accuracy: Calibration curves for As, Cd, Pb, and Hg showed excellent linearity; CCV recoveries were within ±10%.
• Interference Correction: Half-mass correction effectively mitigated REE++ overlaps on As and Se, improving accuracy in high-REE samples.
• Sample Analysis: Quantitative data for two cannabis samples and commercial products revealed As, Cd, Pb, and V levels up to 160 ppb, demonstrating method sensitivity and robustness.
• Spike Recoveries: Triplicate spike recoveries ranged between 93–104% for most elements, confirming method reliability.

Benefits and Practical Applications

• High Throughput: HMI capability enables analysis of high-matrix cannabis samples without extensive dilution.
• Comprehensive Profiling: Quick Scan ensures detection of elements beyond calibration standards for complete sample characterization.
• Regulatory Compliance: Provides reliable data for safety testing and nutritional labeling in cannabis quality control labs.

Future Trends and Potential Applications

• Enhanced Data Analytics: Integration with AI for real-time interpretation of multi-element datasets in quality assurance.
• Expanded Matrices: Application to complex cannabis-derived formulations such as edibles, topicals, and concentrates.
• Miniaturization and Field Analysis: Development of portable plasma-based systems for on-site screening of contaminants.

Conclusion

The Agilent 7800 ICP-MS method offers a robust, sensitive, and efficient approach for multi-element analysis in cannabis matrices. Through advanced interference management, automated tuning, and comprehensive QC, this workflow meets the stringent demands of regulatory testing and supports safe production practices.

Reference

• Filipiak-Szok et al., Journal of Trace Elements in Medicine and Biology, 30, 2015, 54–58