Preparation of Polydopamine-Based Electrospun Nanofibers as an Efficient Adsorbent for Solid-Phase Extraction of Trace Mycotoxins Followed by HPLC

The efficient solid-phase extraction (SPE) adsorbents for the detection of trace mycotoxins are challenging to prepare in an essential sample pretreatment. In this study, an efficient SPE adsorbent, an electrospun polystyrene/polyacrylonitrile nanofiber membrane modified by polydopamine (PDA@PS/PAN NFM), was prepared and characterized. It is shown that the introduction of PDA provided abundant amino groups and phenolic hydroxyl groups for the porous network structure of these nanofibers, which can contribute rich interactions (such as hydrogen bonding, electrostatic interaction, and π–π stacking) on the analyte to improve the extraction efficiency of sample pretreatment. The extraction performance of PDA@PS/PAN NFM was probed by selecting zearalenone (ZEN) as the representative mycotoxin, and the effects of several factors on the adsorption and desorption in the SPE process were systematically investigated and optimized. Under the optimal conditions, the limit of detection (LOD) was 4.17 μg/kg, the intraday and interday relative standard deviations (RSDs) were 3.3–5.2 and 3.7–5.1%, respectively, and the recovery was 87.3–99.5%. Additionally, PDA@PS/PAN NFM displayed excellent reproducibility with a good reusability of 20 times. The results indicated that the PDA-functionalized nanofiber membrane exhibited extensive application prospects in the efficient separation, preconcentration, and decrease of interference of trace mycotoxins in a complex sample matrix.