Drugs of Abuse Screening and Quantification Directly from Urine Using Paper Spray Technology for Clinical Research

Importance of the topic

Rapid and reliable screening of drugs of abuse is essential in clinical research and toxicology. Traditional LC / MS workflows often require extensive sample preparation and long chromatographic run times, limiting throughput. Paper spray technology offers a streamlined approach to analyze dried biofluid spots in under two minutes, reducing reagent use and simplifying workflows.

Study objectives and overview

This study aimed to demonstrate a high-throughput paper spray method for:

• Screening 19 common drugs of abuse directly from dried urine spots.
• Quantifying cocaine and its primary metabolite, benzoylecgonine, over a wide concentration range.

Methodology

A small volume (8 μL) of spiked human urine was applied to triangular paper strips on Thermo Scientific VeriSpray sample plates. After drying, a rewet solvent was added to extract analytes, followed by a spray solvent (90 % acetonitrile, 10 % water, 0.01 % acetic acid). A high voltage (3.8 kV) was applied for electrospray ionization. Data were acquired for one minute per sample, with five replicates for screening and three for quantification. Three transitions per compound were monitored on a TSQ Quantis mass spectrometer.

Used Instrumentation

• Thermo Scientific VeriSpray ion source with 10-plate automatic plate loader.
• Thermo Scientific TSQ Quantis tandem mass spectrometer.
• Xcalibur software for sequence control.
• TraceFinder software for data processing.

Main results and discussion

Screening cutoffs were defined by a minimum area-under-curve four times the blank response. All 19 drugs met criteria, with signal-to-noise ratios ranging from ~5 to >500 at cutoff levels. Semi-quantitative calibration curves for selected classes showed linearity. Quantification of cocaine and benzoylecgonine yielded limits of quantitation of 5 ng/mL, with precision (%RSD) and accuracy within ±15 % across calibrator and QC levels. The one-minute acquisition window provided ample scans for reliable detection across a 19-analyte panel.

Benefits and practical applications

• Minimal sample preparation and solvent consumption.
• High throughput: up to 24 samples per plate in ~1 minute each.
• Automated plate loading and sequence control enhance lab efficiency.
• Direct analysis of dried urine spots suitable for decentralized sampling.

Future trends and potential applications

Further developments may include expanding analyte panels to include emerging drugs, integrating with point-of-care devices, coupling paper spray sources to high-resolution instruments, and implementing real-time monitoring in clinical and forensic settings.

Conclusion

This work demonstrates that automated paper spray technology on the VeriSpray platform enables rapid, reliable screening of 19 drugs of abuse and accurate quantification of cocaine and benzoylecgonine directly from dried urine spots. The approach offers a compelling alternative to traditional LC / MS methods for high-throughput clinical research applications.