Detection of Mycotoxins in Corn Meal Extract Using Automated Online Sample Preparation with LC-MS/MS

Importance of the topic

Mycotoxins are toxic secondary metabolites produced by fungi that can contaminate grains and pose serious risks to human and animal health, including organ damage and carcinogenesis. Corn is particularly susceptible to contamination by multiple mycotoxins, and regulatory agencies worldwide enforce strict maximum levels. Sensitive, reliable, and high-throughput methods are therefore essential for routine monitoring in food safety laboratories.

Objectives and study overview

This work aimed to develop a rapid, automated online sample-preparation LC-MS/MS workflow for the simultaneous detection and quantification of multiple mycotoxins in corn meal extract. By integrating Thermo Scientific Transcend TLX-1 TurboFlow technology with a TSQ Vantage triple-quadrupole mass spectrometer, the study sought to shorten assay time, reduce manual handling, and achieve detection limits compliant with European Union regulations.

Methodology

• Sample preparation: 5 g corn meal extracted with 70% MeOH/water, sonicated for 60 min, stored overnight, and centrifuged. Supernatant equivalent to 0.2 g solid used for calibration and QC.
• Automated online cleanup: Transcend TLX-1 TurboFlow columns for positive and negative electrospray ionization (ESI).
• LC conditions: Hypersil GOLD analytical columns (2.1×50 mm or 2.1×100 mm, 1.9 µm) with gradient elution using formic acid in water and ACN.
• MS/MS detection: TSQ Vantage triple-quadrupole instrument with heated ESI source; positive mode for eight analytes, negative mode for DON, NIV, and 3-AcDON.
• Calibration: Matrix-matched standards covering two orders of magnitude; linearity (r2>0.99) assessed for all targets.

Instrumental setup

• Thermo Scientific Transcend TLX-1 system with TurboFlow Cyclone-P columns.
• TSQ Vantage triple-quadrupole mass spectrometer.
• Heated electrospray ionization source (H-ESI).
• Aria OS software for method control.

Key results and discussion

Chromatograms showed baseline separation for eight mycotoxins in both solvent and matrix extracts. LOQs in positive mode ranged from 0.5 to 50 ng/g; in negative mode DON, NIV, and 3-AcDON achieved LOQs of 25 ng/g with r2≈0.993. Signal enhancement for fumonisins (FB1, FB2) highlighted matrix effects, suggesting future use of isotope-labeled internal standards. Calibration curves exhibited excellent linearity (r2>0.99) across dynamic ranges, meeting EU maximum levels.

Benefits and practical applications of the method

The automated online workflow eliminates labor-intensive offline cleanup, improving reproducibility and reducing turnaround time. High sample throughput can be achieved by multiplexing methods on TLX-2 or TLX-4 systems. The approach is adaptable to routine food safety testing, ensuring compliance with regulatory limits.

Future trends and potential applications

Future research will extend the method to diverse food matrices, incorporate isotope-labeled standards for matrix correction, and explore larger injection volumes on TurboFlow columns to further lower quantitation limits. Integration with multiplexed TLX platforms and advanced data processing will enhance throughput and broaden applicability to other contaminants.

Conclusion

The presented automated online sample-preparation LC-MS/MS method delivers rapid, sensitive, and robust quantification of multiple mycotoxins in corn meal extract. It reduces manual steps, meets stringent regulatory requirements, and offers scalable throughput for routine food safety laboratories.

References

• Pitt, J.I. “What are mycotoxins?” Australian Mycotoxin Newsletter 1996, 7(4), 1.
• Spanjer, M.C., Rensen, P.M., Scholten, J.M. “LC-MS/MS multi-method for mycotoxins after single extraction,” Food Addit. Contam. Part A 2008, 25, 472–489.
• Shephard, G.S. “Determination of mycotoxins in human foods,” Chem. Soc. Rev. 2008, 37, 2468–2477.
• Commission Regulation (EC) No 1881/2006. “Setting maximum levels for certain contaminants in foodstuffs,” EUR-Lex, 2011.
• Li, W., Herrman, T.J., Dai, S.Y. “Rapid determination of fumonisins in corn-based products,” J. AOAC Int. 2010, 93, 1472–1481.
• European Commission. “Maximum levels of mycotoxins in foodstuffs,” 2006R1881, 2010.
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