Rapid detection of natural plant toxins using probe ESI unit combined with quadrupole time of flight mass spectrometer

Significance of the Topic

Many animals and plants produce natural toxins that can contaminate food supplies and pose serious health risks, including high fatality rates. Rapid and reliable screening methods for these toxins are essential to ensure food safety and monitor contamination events.

Objectives and Overview of the Study

This study aimed to develop and validate a fast, direct analysis approach for detecting natural plant toxins in Colchicum autumnale and Narcissus tazetta. By integrating a probe electrospray ionization (PESI) source with a quadrupole time-of-flight mass spectrometer (Q-TOF), the research sought to minimize sample preparation time while achieving high mass accuracy and specificity.

Methodology and Sample Preparation

Plant leaf and bulb sections were obtained from garden suppliers and cut into 1–2 mm thick, 5 mm square pieces. Samples were placed in a 96-well plate and treated with 50% ethanol–water solution. The PESI probe directly sampled the liquid, and ionization occurred at the probe tip under high voltage. Each analysis required approximately 5 minutes of preparation and 0.5 minutes of acquisition time.

Used Instrumentation

• PESI-Q-TOF mass spectrometer (Shimadzu Corporation)
• DPiMS QT + LCMS-9050 system
• LabSolutions Insight Explore software for data acquisition and processing

Main Results and Discussion

Direct PESI-Q-TOF analysis yielded high-resolution mass spectra with mass errors below 1 mDa. Key alkaloids detected in Colchicum autumnale included colchicine (m/z 400.1756) and demecolcine, while Narcissus tazetta samples revealed lycorine, tazettine, galanthamine, arginine, and hexose-based saccharides. MS/MS fragmentation patterns matched predicted product ions, confirming compound identities. The entire workflow detected and identified toxins in under 6 minutes with minimal sample handling.

Benefits and Practical Applications of the Method

• Minimal sample preparation reduces turnaround time.
• Direct analysis on plant material limits potential contamination and loss.
• High mass accuracy ensures reliable toxin identification.
• Fast screening capability supports food safety monitoring and forensic investigations.

Future Trends and Applications

Advancements may include coupling PESI-Q-TOF with automated sample handling for high-throughput screening and expanding the method to other natural toxin classes. Integration with portable mass spectrometers could enable on-site detection in agricultural and field settings. Further method optimization may enhance sensitivity and quantitation for trace-level monitoring.

Conclusion

The combination of probe electrospray ionization and quadrupole time-of-flight mass spectrometry provides a rapid, accurate, and user-friendly approach for direct detection of natural plant toxins. This method holds promise for improving food safety protocols and enabling timely response to toxin-related incidents.