A simple and low-cost sample preparation for the effective extraction, purification and enrichment of aflatoxins in wheat by combining with ionic liquid-based dispersive liquid–liquid microextraction

The direct extraction, purification, and enrichment of four aflatoxins (AFs) in wheat were achieved by combining solvent extraction and ionic liquid-based dispersive liquid–liquid microextraction (IL-DLLME). High-performance liquid chromatography coupled with fluorescence detection (HPLC-FD) was applied for the determination of AFs. The feature of the developed technique is that some tedious and time-consuming steps are avoided and the organic solvent consumption is low. The IL-DLLME allows the isolation, purification and enrichment of AFs from the methanol extract using a simple procedure. The effective enrichment was mainly due to the multiple-interaction, including hydrophobic, π-π and hydrogen bonding interactions, between IL and AFs. The parameters affecting the extraction efficiency were thoroughly investigated. This extraction method permits the determination of four AFs with LOD (S/N = 3) and LOQ (S/N = 10) in the range of 0.015–0.20 μg kg−1 and 0.045–0.75 μg kg−1, respectively. The recoveries from four spiked wheat samples ranged from 80.8% to 112.5% with RSDs of 0.8%-4.7% (n = 3), demonstrating the great potential of this proposed procedure for the analysis of AFs in solid samples.