Quantitative analysis of antifungal drugs using PaperSpray tandem mass spectrometry for clinical research

Significance of the Topic

Therapeutic monitoring of antifungal agents such as voriconazole, itraconazole, and posaconazole is vital for managing invasive fungal infections, particularly in immunocompromised and pediatric patients where pharmacokinetics can vary significantly. Rapid and accurate quantitation supports dose adjustment and improves clinical outcomes in research settings.

Goals and Study Overview

The study aimed to develop a reproducible PaperSpray tandem mass spectrometry workflow using the VeriSpray ion source on a Thermo Scientific TSQ Altis mass spectrometer for simultaneous quantitation of three antifungal drugs in human serum.

Methodology and Instrumentation

Sample Preparation:

• Calibration standards 0.1–10 µg/mL in pooled human serum.
• 4 µL serum mixed with isotopically labeled internal standards; posaconazole IS replaced by itraconazole D4.
• Samples spotted onto VeriSpray cartridges and dried for 30 minutes.

PaperSpray and MS Conditions:

• Solvent: acetonitrile/acetone/water (85/10/5) with 0.01% acetic acid, applied in 10 µL increments with time-dependent delays.
• Ionization voltage 4.2 kV, cycle time 0.8 s, Q1/Q3 resolution 0.7 Da.
• SRM transitions and optimized collision energies set for target analytes and internal standards.
• Data acquired and processed with TraceFinder 4.1; LOD calculated as 3×sb/m.

Instrumentation:

• Thermo Scientific TSQ Altis triple quadrupole mass spectrometer.
• Thermo Scientific VeriSpray PaperSpray ion source with 24-tip sample plate.
• Thermo Scientific TraceFinder software.

Main Results and Discussion

• Successful simultaneous quantitation of voriconazole, itraconazole, and posaconazole with calibration curves showing linearity (R2>0.997).
• Limits of detection ranged from 16 to 43 ng/mL, suitable for clinical research concentration ranges.
• Total analysis time per spot was approximately 2 minutes, including automated extraction and MS analysis.

Benefits and Practical Applications

• No sample pretreatment or chromatographic separation required.
• Rapid, high-throughput workflow enabling same-day results for clinical studies.
• Capability to monitor multiple antifungal agents in a single run supports efficient therapeutic drug monitoring in research and potentially clinical settings.

Future Trends and Opportunities

Anticipated developments include expansion of PaperSpray assays to additional drug classes, integration with clinical laboratory information systems for real-time dose guidance, and miniaturization of portable MS platforms for point-of-care monitoring.

Conclusion

The VeriSpray PaperSpray MS workflow on a TSQ Altis instrument provides a robust, fast, and reproducible method for quantitative analysis of key antifungal drugs in serum, offering significant advantages for clinical research applications.

Reference

1. Wang H.; Liu J.; Cooks R. G.; Ouyang Z. Paper Spray for Direct Analysis of Complex Mixtures Using Mass Spectrometry. Angewandte Chemie International Edition 2010, 49(5), 877–880.
2. Manicke N. E.; Bills B. J.; Zhang C. Advances and Challenges in Analysis of Biofluids by Paper Spray MS. Bioanalysis 2016, 8(6), 589–606.