Food Analysis by Microextraction Methods Based on the Use of Magnetic Nanoparticles as Supports: Recent Advances

In the last years, nanotechnology progress has impact several fields of food science. In food analysis, new nanomaterials have been developed in order to extract minority food components. Recently, magnetic nanoparticles (MNPs) have been used as sorbents in methodologies based on dispersive solid-phase microextraction. The main advantage of MNPs as sorbent is their magnetic behavior, which it allows to separate from the food matrix minor components with the aid of a magnet. This MNP property avoids tedious centrifugation and filtration steps, and in turn decreasing sample preparation times and source of errors. The MNPs as sorbent do not need to package in a column, and the separation process is quickly. Other advantages of MNPs in the microextraction of food components are low cost, high concentration factors, and low detection limits; this has allowed the diversification of its applications. Several methods and compounds have been used in the design and functionalization of MNPs, this review focuses in the description of these, especially for the analysis of contaminants (for example, pesticides, heavy metals, drugs, compounds produced during food processing, adulterants, among others).