Screening of plant and fungal metabolites in wheat, maize and animal feed using automated on-line clean-up coupled to high resolution mass spectrometry

A wide range of plant and fungal metabolites can occur in cereals and feed but only a limited number of target compounds are sought. This screening method is using a database of over 600 metabolites to establish contamination profiles in food and feed. Extracts were injected directly into an automated turbulent flow sample clean-up system, coupled to a liquid-chromatography-high-resolution-mass-spectrometer (Orbitrap). Compound identification criteria for database searching were defined and the approach was validated by spiking plant and fungal metabolites into cereals and feed. A small survey of market samples (15) and quality control materials (9) of maize, wheat and feed was conducted using this method. Besides regulated and known secondary metabolites, fumiquinazoline F, fusarochromanone and dihydrofusarubin were identified for the first time in samples of maize and oats. This method enables clean-up of crude extracts within 18 min and screening and confirmation of a wide range of different compound classes.