Quantitative analysis of mycotoxins in cereal foods by collision cell fragmentation-high-resolution mass spectrometry: performance and comparison with triple-stage quadrupole detection

Abstract

A liquid chromatography-high-resolution mass spectrometry (LC-HRMS) method for the simultaneous determination of aflatoxins (B₁, B₂, G₁, G₂), ochratoxin A, deoxynivalenol, zearalenone, T-2 and HT-2 toxins in wheat flour, barley flour and crisp bread was developed. Mycotoxin fragmentation patterns obtained by high-energy collision dissociation (HCD) were investigated to obtain quantitative and confirmatory information (two characteristic masses per mycotoxin) using Orbitrap™-based high-resolution mass spectrometry. LC-HRMS (full-scan) detection carried out by HCD allows the monitoring of the pseudo-molecular ion and an additional characteristic fragment (for each mycotoxin) with mass accuracy in the range 0.1–3.9 ppm, meeting current European regulatory requirements for LC-MS confirmatory analysis. A sample preparation procedure based on polymeric solid-phase extraction cartridges was applied, allowing recoveries higher than 74% for nine mycotoxins, with a relative standard deviation lower than 13%. Detection limits in the range 0.5–3.4 µg kg⁻¹ were obtained for three cereal matrices. A critical comparison between the proposed method and a validated method based on triple quadrupole mass spectrometry showed similar performance in terms of detection limits, recoveries and repeatability, and matrix effects. Based on an efficient sample extraction and clean-up, the LC-HCD-HRMS method reported here represents a reliable and robust alternative tool for mycotoxin analysis in food matrices as compared with well-established triple quadrupole-based approaches.

Keywords:

• LC/MS
• in-house validation
• mycotoxins
• Fusarium
• aflatoxins
• ochratoxin A
• zearalenone
• bakery products
• cereals