From soft drugs to legal medication

Significance of the Topic

Monitoring trace levels of herbicides, their transformation products in water and active cannabinoids in pharmaceutical preparations is essential for environmental protection, regulatory compliance and ensuring patient safety in medical cannabis applications.

Objectives and Study Overview

This application report describes the development, validation and accreditation of a robust GC-MS/SIM method for simultaneous quantification of priority pesticides in water and quality control of cannabis‐derived active ingredients.

Methodology and Instrumentation

• Sample preparation by solid-phase extraction for water analytes and solvent extraction of cannabis matrices.
• Instrumentation: Shimadzu GCMS-QP-5000 and GCMS-QP2010 operated in selected-ion monitoring mode.
• Use of deuterated internal standards to compensate for matrix effects and instrument drift.
• Calibration across working ranges from 3.3 to 600 ng/L; limits of detection down to 0.1 ng/L and quantification to 0.33 ng/L.
• Validation and accreditation under ISO/IEC 17025, following EU SANCO guidelines, EPA Methods 525.2/526.1, ASTM D4128-01 and Eurachem/CITAC uncertainty protocols.

Main Results and Discussion

• Established retention times, characteristic SIM ions, LODs, LOQs and linear ranges for 25 target pesticides and metabolites.
• Demonstrated expanded uncertainty of 10 % at 100 ng/L and consistent inter-laboratory comparison results.
• Quality control of dronabinol (synthetic THC) showed >98 % purity and clear separation of CBD and THC peaks.
• Achieved THC quantification in food matrices with a detection limit of 0.1 mg/kg, enabling compliance with recommended BgVV guidelines.

Benefits and Practical Applications

The validated GC-MS/SIM protocol provides laboratories with a high‐throughput, sensitive and selective method for environmental monitoring of organic micropollutants and reliable standardization of medical cannabis products, supporting regulatory approval and patient care.

Future Trends and Potential Applications

• Adoption of high-resolution mass spectrometry for broader analyte coverage and improved specificity.
• Automation of sample preparation and data analysis to enhance throughput.
• Extension of multi-residue methods to emerging contaminants and novel cannabinoid derivatives.
• Global harmonization of analytical guidelines for pesticide and cannabinoid quantification.

Conclusion

The described GC-MS/SIM approach offers a fully accredited, sensitive and reproducible platform for both environmental and pharmaceutical analysis, aligning with international standards and delivering robust quality control.

Reference

1. EURAU position paper EU1-01-A56, Keeping Raw Drinking Water Resources Safe from Pesticides, 2001.
2. Quality Control Procedures for Pesticide Residues Analysis: Guidelines for Residues Monitoring in the European Union, 3rd ed., 2003.
3. EPA Method 526.1: Determination of Selected Semi‐volatile Organic Compounds in Drinking Water by SPE and Capillary Column GC/MS, Rev. 1.0.
4. EPA Method 525.2: Determination of Selected Semi‐volatile Organic Compounds in Drinking Water by SPE and Capillary Column GC/MS, Rev. 2.0.
5. Shimadzu Application Note SCA 280-004.
6. Macherey-Nagel Application Note No. 155.
7. Soniassy R., Sandra P., Schlett C., Water Analysis of Organic Micropollutants, Hewlett Packard, 1994.
8. Methods of Analysis by the U.S. Geological Survey Organic Geochemistry Research Group, O-2132-99.
9. Auersperger P., Kus J., Gorenc B., Proceedings of the 7th International Symposium on Advances in Analytical Separation Science, Pörtscach/Wörthersee, 2002.
10. Auersperger P., Kus J., Slovenski kemijski dnevi, Maribor, 2000.
11. Auersperger P., Kus J., Slovenski kemijski dnevi, Maribor, 2003.
12. ASTM D4128-01.
13. Eurachem/CITAC Guide to Quantifying Uncertainty in Analytical Measurement, 2nd ed., 2000.
14. ISO 10843-2:2000.
15. EURACHEM/CITAC Guide to Achieving Comparable Results in Chemical Measurement, LGC, 2002.
16. European Commission Document No. SANCO/10476/2003 rev 1.