LC-MS/MS Method Development and Validation for the Quantitative Determination of Regulated Mycotoxins in Cereal Grain Flours Using Simplified Sample Preparation Conditions on Xevo TQ-XS

Significance of the Topic

Mycotoxins are toxic secondary metabolites produced by molds that commonly contaminate cereal grains. Due to their significant chronic dietary risks, regulatory limits have been established worldwide. Sensitive, reliable, and efficient analytical methods are essential for ensuring food safety and regulatory compliance.

Objectives and Study Overview

This work aimed to develop and validate a quantitative LC-MS/MS method for simultaneous determination of twelve regulated mycotoxins in cereal flours. The focus was on a rapid, simplified sample preparation workflow and compliance with European Commission regulations (1881/2006, 401/2006) and SANTE guidelines.

Methodology and Instrumentation

A streamlined “extract-dilute-shoot” protocol was implemented: ground flour was spiked with 13C-labelled internal standards, extracted with acidified acetonitrile–water, centrifuged, diluted, and optionally filtered. Calibration employed eight-point solvent and matrix-matched curves using isotopically labelled internal standards for accurate quantitation.

Instrumentation:

• UPLC: ACQUITY UPLC I-Class with BEH-C18 column (2.1 × 100 mm, 1.7 μm)
• Mass spectrometer: Xevo TQ-XS triple quadrupole with electrospray ionization
• Software: MassLynx v4.2 and TargetLynx XS

Main Results and Discussion

The method demonstrated excellent linearity (R2 > 0.994), with instrumental LODs as low as 0.75 pg/mL for aflatoxins and 0.0075–1.5 ng/mL for other mycotoxins. Method LOQs ranged from 0.03 to 60 μg/kg. Recoveries and repeatability met EU performance criteria (recoveries 71–115%, RSDr ≤ 9% with internal standards). Significant matrix effects—suppression for nivalenol and strong enhancement for ochratoxin A—highlight the necessity of internal standard correction or matrix-matched calibration. The simplified workflow eliminated cleanup steps, improving throughput and reducing solvent consumption.

Benefits and Practical Applications

This validated approach provides:

• High sensitivity for multiple mycotoxins across diverse cereal matrices (wheat, oats, rice, maize, gluten-free blends)
• A rapid, resource-efficient sample preparation without clean-up
• Robust quantitation using 13C-labelled standards to correct for matrix effects
• Full compliance with European regulatory requirements for food safety monitoring

Future Trends and Possibilities of Utilization

Future developments may include expanding to emerging mycotoxins, integrating high-throughput automation, coupling with high-resolution MS for non-target screening, and adopting miniaturized or green extraction techniques to further reduce environmental impact.

Conclusion

The presented UPLC-MS/MS method on the Xevo TQ-XS platform is fit-for-purpose for routine quantitative analysis of regulated mycotoxins in cereal flours. It combines high sensitivity, simplicity, and regulatory compliance, making it a valuable tool for quality control and food safety laboratories.

References

Validation criteria derived from European Commission Regulations 1881/2006 and 401/2006, SANTE guidelines, and Eurachem method validation principles.