Rapid and quantifiable screening method for 64 drugs in humanblood by direct probe ionization/ tandem mass spectrometry (DPiMS)

Importance of the Topic

Rapid and reliable detection of multiple drugs in human blood is crucial in forensic toxicology, clinical diagnostics and workplace safety. Traditional LC-MS/MS workflows require laborious sample preparation and long run times, limiting throughput. A streamlined, high-speed direct ionization approach can expedite decision making in emergency cases, improve laboratory efficiency and reduce operational costs.

Objectives and Study Overview

This study introduces an ultra-rapid screening method for 64 commonly encountered drugs in human whole blood using direct probe ionization coupled to tandem mass spectrometry (DPiMS-8060). The goal was to eliminate extensive sample cleanup and achieve quantitative performance comparable to conventional LC-MS/MS within minutes.

Methodology and Instrumentation Used

• Sample Preparation: Ten microliters of whole blood were diluted tenfold with a deuterated internal standard solution, followed by a twofold dilution in ethanol. A 10 µL aliquot was spotted onto a sample plate (total time 5 minutes).
• Instrument Configuration: A Shimadzu LCMS-8060 triple quadrupole mass spectrometer equipped with the DPiMS-8060 direct probe ionization interface.
• Ionization and Data Acquisition: Probe electrospray ionization in positive/negative modes; scheduled selected reaction monitoring (SRM) of 64 analytes; 1 ms dwell time per transition; ±3.0 kV applied voltage.

Main Results and Discussion

Sensitivity studies in spiked control blood showed limits of quantitation as low as 1 ng/mL for 25 analytes, with R2 values above 0.95 for all compound calibration curves. The total analysis time for 64 drugs was 3.2 minutes, compared with over 30 minutes by LC-MS/MS. Real postmortem blood samples analyzed by DPiMS-8060 demonstrated full agreement in compound detection with an established LC-MS/MS library, validating applicability to authentic forensic specimens.

Benefits and Practical Applications

• Significantly reduced turnaround time enhances lab throughput.
• Minimal sample handling lowers risk of contamination and operator error.
• Quantitative performance meets forensic and clinical requirements.
• Direct analysis enables on-site or point-of-care testing potential.

Future Trends and Applications

Further developments may expand the drug panel, integrate automated sample handling and apply the method to other biological matrices such as urine or tissue. Coupling DPiMS with high-resolution mass spectrometry or machine-learning spectral interpretation could further improve specificity in complex cases. Widespread adoption of ambient ionization techniques will continue to transform rapid screening workflows.

Conclusion

The DPiMS-8060 method delivers ultra-rapid, high-sensitivity screening of 64 drugs in whole blood without extensive sample preparation. Its validated quantitative performance and agreement with LC-MS/MS results demonstrate its practicality for forensic, clinical and quality-control applications.

Reference

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