Ultrafast Analysis of THCCOOH in Urine Using the Agilent RapidFire High-Throughput Mass Spectrometry System

Importance of the Topic

Monitoring THCCOOH, the primary urinary metabolite of delta9-tetrahydrocannabinol, is critical for forensic toxicology and clinical drug testing. Rising sample volumes and the need for rapid turn-around have exposed limitations in conventional GC/MS and LC/MS workflows that involve time-consuming sample preparation.

Objectives and Study Overview

This work aimed to develop and validate an ultrafast solid-phase extraction tandem mass spectrometry workflow using the Agilent RapidFire system. The goals were to achieve analysis cycles under 15 seconds, preserve accuracy and precision comparable to LC/MS or GC/MS assays, and eliminate offline sample cleanup.

Methodology and Instrumentation

Sample Preparation

• Calibration standards prepared by spiking drug-free human urine with THCCOOH across 5–1,000 ng/mL.
• Base hydrolysis at 65 °C for 15 minutes in sodium hydroxide.
• Tenfold dilution in 50:50 methanol:water containing 0.1% formic acid.

Instrumentation

• Agilent RapidFire 360 system for automated SPE.
• Agilent 6490 Triple Quadrupole mass spectrometer.
• RapidFire cartridge E (reversed-phase C8).
• MassHunter Qualitative and Quantitative Analysis software B.05.00.
• Buffers: ammonium acetate/formic acid aqueous phase, methanol phase, ethyl acetate/isopropanol phase.

Key Results and Discussion

The method achieved 12-second cycle times without any offline cleanup. Calibration curves exhibited linearity (R2 = 0.995) from 5 to 1,000 ng/mL. Intraday and interday accuracy remained within ±15% and precision within 10%. No significant matrix effects were observed when comparing urine to PBS calibrations. More than 2,000 consecutive injections maintained stable response with <10% variation and <2% accuracy drift.

Practical Benefits and Applications

Throughput exceeds 240 samples per hour, significantly reducing hands-on time and consumable use. The dilute-and-shoot approach streamlines laboratory workflows. Forensic and clinical laboratories can meet high-volume demands without sacrificing data quality.

Future Trends and Potential Applications

Rapid SPE-MS/MS platforms may be applied to other drug metabolites, biomarkers, and high-throughput screening assays. Further integration with laboratory automation and advanced data processing will enhance efficiency. Developments in cartridge chemistries and mass spectrometer speed are expected to broaden applicability and reduce analysis times even further.

Conclusion

The Agilent RapidFire high-throughput mass spectrometry system delivers a validated, ultrafast method for quantifying THCCOOH in urine. It matches the analytical performance of traditional methods while offering >10× faster sample throughput, addressing the evolving demands of modern forensic toxicology.