Evaluation of LC-high-resolution FT-Orbitrap MS for the quantification of selected mycotoxins and the simultaneous screening of fungal metabolites in food

Abstract

A liquid chromatography-high-resolution mass spectrometry-based method is reported for the quantification of 20 selected mycotoxins and the simultaneous screening for 200 fungal metabolites in food. For regulated mycotoxins, such as aflatoxins, fumonisins, ochratoxin A, zearalenone and trichothecenes, the evaluation of the method performance characteristics, such as precision, trueness, limit of detection and matrix effects, has been exemplified for the matrix maize. In the case of the limit of detection, an alternative evaluation approach for high-resolution FT-Orbitrap data is proposed. Measurements of the signal-to-noise ratios obtained from ‘full-profile mode’ data led to detection limits between 8 and 160 ng g⁻¹. Eight naturally contaminated wheat- and maize-based matrix test materials, originating from interlaboratory comparison studies, were used to confirm the trueness of the method for deoxynivalenol, zearalenone, fumonisin B₁ and B₂, HT-2, and T-2 toxin. In addition to accurate quantification of the most relevant mycotoxins, the full-scan chromatograms were used to investigate the potential of the FT-Orbitrap to screen simultaneously for a large number of fungal metabolites. First, a list of 200 metabolites, potentially being present in food samples, was established. Next, specific detection and identification criteria were defined, which are based on accurate mass, peak intensity and isotopologue ratio. The application of these criteria to the suspected metabolites from the list resulted in the putative identification of 13 fungal metabolites in addition to the target toxins.

Keywords:

• accurate mass
• fungal metabolites
• liquid chromatography
• LC-MS
• LOD
• mycotoxins
• FT-Orbitrap
• high-resolution mass spectrometry

Acknowledgements

The authors thank the Federal Country Lower Austria and the European Regional Development Fund (ERDF) of the European Union for financial support (Grant Number GZ WST3-T-95/001-2006). Miroslav Flieger and Marika Jestoi are acknowledged for providing mycotoxin standards. This work contributes to the doctoral thesis of Sylvia M. Lehner.