Automated fluorimetric sensor for the determination of zearalenone mycotoxin in maize and cereals feedstuff

Zearalenone (ZEA), a mycotoxin produced by several Fusarium molds, can be found in many cereals and related products. The toxicity of ZEA has been reported for both humans and animals. Therefore, many countries have adopted regulations in foods and feed materials to limit the exposure to this contaminant. In this paper, we propose a multicommutated flow-through optosensor to quantify ZEA in different cereal samples. ZEA was retained and pre-concentrated on C₁₈ silica gel, and the use of the multicommutated flow manifold allowed the automated retention/desorption of ZEA on the solid microbeads by the use of appropriate carrier/eluting solutions, hence increasing the selectivity and sensitivity of the system. The native fluorescence of ZEA was recorded on the solid phase at λ_exc/λ_em of 265/465 nm/nm. A QuEChERS procedure was used to carry out the extraction of ZEA from different cereal samples (feedstuff materials). Recovery studies were performed to assess the accuracy of the method, obtaining recovery yields between 93% and 107% in all the analyzed samples. LC-MS was employed as reference method. The quantitation limit of the proposed method was low enough to fulfill the maximum residue levels established by the Commission of the European Communities, thus demonstrating its potential use for the analysis of ZEA in feedstuffs.