Bimodal porous silica nanomaterials as sorbents for an efficient and inexpensive determination of aflatoxin M in milk and dairy products.

An extraction procedure was developed for the determination of aflatoxin M in milk and dairy products. A sorbent based on UVM-7 mesoporous silica was used as solid phase for the sample clean-up, and the analyte determination was carried out by HPLC coupled to a fluorescence detector. The material architecture was characterized by transmission electronic microscopy, X-ray diffraction, Si NMR and nitrogen adsorption-desorption. After the optimization of extraction parameters, the influence of the matrix has been evaluated, obtaining recoveries in the range 78-105% for whole and skimmed milk and yogurt matrix. The reusability of the material was also proved. The sensitivity of the method was also evaluated, and a LOQ (0.015 μg kg) below the European legislation limit was obtained. The procedure was successfully applied for the determination of aflatoxin M in real samples. The results were compared with those obtained with a reference method, being the results statistically comparable.