Detection of THC Metabolites in Urine by LCMS- 8050 with Supported Liquid Extraction Method

Importance of the Topic

Monitoring cannabis consumption through its metabolites in urine is critical for forensic, clinical and workplace testing. Sensitive and selective analytical methods help ensure accurate detection of Δ9-tetrahydrocannabinol (THC) metabolites long after the parent drug has been cleared.

Objectives and Study Overview

This study aimed to develop and validate a rapid LC-MS/MS method using supported liquid extraction (SLE) to quantify THC-COOH and 11-OH-THC in human urine. The method was designed to meet UNODC criteria for mass spectrometry-based detection of cannabinoid metabolites.

Methodology and Instrumentation

Sample preparation combined enzymatic hydrolysis with β-glucuronidase followed by SLE cleanup. Chromatographic separation employed a biphenyl column (100 mm×2.1 mm, 2.6 µm) under a gradient of 0.2% formic acid in water and methanol. Detection used scheduled multiple reaction monitoring in positive ion mode. Key validation parameters included linearity, limit of quantitation, recovery, matrix effect, accuracy, precision, and specificity.

Used Instrumentation

• Shimadzu LCMS-8050 triple quadrupole mass spectrometer
• Biotage ISOLUTE® SLE+ 1 mL cartridges
• LabSolutions™ software for MRM optimization

Main Results and Discussion

The calibration curve was linear over 5–200 ng/mL with R²≥0.992. The LOQ was established at 5 ng/mL (S/N>10), well below the 15 ng/mL threshold. Extraction recovery ranged from 92% to 106%, while matrix effects varied between 71% and 101%. Accuracy fell between 90.4% and 106.4%, and intra- and interday precision RSDs did not exceed 9%. No interfering peaks were observed from co-administered drugs or endogenous urine constituents.

Benefits and Practical Applications of the Method

This validated LC-MS/MS approach provides:

• High sensitivity for routine urine screening
• Compliance with UNODC guidelines
• Efficient sample cleanup via SLE
• Reduced run times and operational costs through automated MRM optimization

Future Trends and Opportunities

Further developments may include integration with high-throughput robotic workflows, expansion to blood and oral fluid matrices, and enhanced data processing using machine learning to improve throughput and analytical accuracy.

Conclusion

The described LCMS-8050 method, coupled with supported liquid extraction, meets all UNODC validation criteria for detecting THC metabolites in urine. Its robustness, sensitivity, and streamlined workflow make it a valuable tool for forensic and clinical laboratories.

Reference

Ang May Yen, Udi Jumhawan, Norsalihan Bt Md Amin, Nurul Syamimi Bt Salleh, Doriane Toinon; Detection of THC Metabolites in Urine by LCMS-8050 with Supported Liquid Extraction Method; Shimadzu Application News; First Edition: Apr. 2021.