Selective extraction and enrichment of aflatoxins from food samples by mesoporous silica FDU-12 supported aflatoxins imprinted polymers based on surface molecularly imprinting technique.

In this work, a highly selective surface molecular imprinted polymers (FDU-12@MIPs) were prepared using structural analogues of aflatoxins as the template molecule and mesoporous silica FDU-12 as the carrier. The resulting polymers were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction and attenuated total reflection Fourier transform infrared spectrometer. A highly ordered mesoporous nanostructure was observed in the fabricated polymer. Results showed that the adsorption capacity of FDU-12@MIPs for aflatoxins were higher than that of non-imprinted mesoporous silica polymer (FDU-12@NIPs). FDU-12@MIPs were successfully used as a solid-phase extraction sorbent coupled with HPLC for aflatoxin G2, G1, B2 and B1 determination in food samples. Under optimized conditions, recoveries from the spiked cereals were found to be 82.6%-116.7%, with relative standard deviations ranging from 2.73 to 4.21. The detection limits of aflatoxin G2, G1, B2 and B1 were estimated to be 0.05 μg kg-1, 0.06 μg kg-1, 0.06 μg kg-1 and 0.05 μg kg-1, respectively. Limits of quantifications were estimated to be 0.15 μg kg-1, 0.2 μg kg-1, 0.2 μg kg-1and 0.15 μg kg-1, respectively. The developed method exhibited a favorable linear response toward aflatoxin G2, G1, B2 and B1 in the range of 0.1 μg kg-1-50 μg kg-1, R2 is 0.9992-0.9996. These results indicated that FDU-12@MIPs could be used as an efficient adsorbent of solid phase extraction for enrichment of aflatoxins in real samples.