- Acknowledgements: This work has been supported by MINECO (CTQ2012-37573-C02-02). J.L. Urraca thanks the CEI-Moncloa for a post-doctoral contract. J Gracia-Mora thanks PASPA-UNAM and CONACyT for a grant for his sabbatical leave.
- Authors: J.L. Urraca, J.F. Huertas-Pérez, G. Aragoneses Cazorla, J. Gracia-Mora, A.M García-Campaña, M.C. Moreno-Bondi.
- Reference: Anal. Bioanal. Chem. 408 (2016) 3033-3042.
In this work, we report the synthesis of novel magnetic molecularly imprinted polymers (m-MIPs) and their application to the selective extraction of the mycotoxin citrinin (CIT) from food samples. The polymers were prepared by surface imprinting of Fe3O4 nanoparticles, using 2-naphtholic acid (2-NA) as template molecule, N-3,5-bis(trifluoromethyl)phenyl-N‘-4-vinylphenyl urea and methacrylamide as functional monomers and ethyleneglycol dimethacrylate as cross-linker. The resulting material was characterized by transmission electron microscopy (TEM), and X-ray diffraction (XRD) and Fourier transform infrared spectroscopies (FT-IR). The polymers were used to develop a solid-phase extraction method (m-MISPE) for the selective recovery of CIT from rice extracts prior to its determination by HPLC with UV diode array detection. The method involves ultrasound-assisted extraction of the mycotoxin from rice samples with (7:3, v/v) methanol/water, followed by sample cleanup and preconcentration with m-MIP. The extraction (washing and elution) conditions were optimized and their optimal values found to provide CIT recoveries of 94–98 % with relative standard deviations (RSD) less than 3.4 % (n = 3) for preconcentrated sample extracts (5 mL) fortified with the analyte at concentrations over the range 25–100 μg kg−1. Based on the results, the application of the m-MIPs facilitates the accurate and efficient determination of CIT in rice extracts.
