Zearalenone is one of the most common mycotoxins produced by Fusarium fungi. It has a nonsteroidal
estrogenic effect on living organisms and primarily affects crops growing in a humid climate as well as cereal
products. In addition, this mycotoxin does not degrade during storage or heating. Thus, it is important to control
zearalenone content in food of plant origin. Such matrices are complex and contain many interfering
components, so the analyte should be extracted and preconcentrated for further analysis.
Deep eutectic solvents (DESs) have been proven to be an environmentally safe alternative to toxic
organic extractants. They consist of hydrogen bond acceptor and hydrogen bond donor and are liquid at room
temperature. Composition of DES can be easily varied which allows tuning its properties for selective and
efficient extraction of the target compound. In this study, hydrophobic DESs based on menthol and long-chain
alcohols were studied for the separation of zearalenone from cereal products for the first time.
The suggested sample preparation approach includes two steps (Figure 1). The first one is aimed to
extract the analyte into the solution of DES precursors in a polar solvent. In this case interactions with menthol
and long-chain alcohol, such as hydrogen bonding, can speed up the process and improve its efficiency. The
second step includes injection of the obtained supernatant into deionized water for dispersive liquid-liquid
microextraction. The in situ formation of the DES phase microdroplets is observed throughout the entire volume
of the sample leading to zearalenone preconcentration. The determination of the analyte is carried out by HPLC
with fluorescence detection.