Magnetic-based microextraction systems for the determination of emerging contaminants in environmental liquid samples

The development of novel methodologies for the extraction of emerging contaminants (ECs) based on functionalized magnetic nanoparticles (MNPs) has increased over the past decade. The properties of these materials permit rapid and efficient separation of the adsorbents and/or solvents used as extractants by the application of a magnetic field, avoiding the use of time-consuming and expensive processes. Due to their high surface areas, ease of modification with different materials, and integration with conventional solid-phase extraction systems, such nanoadsorbents are candidates for developing efficient microextraction methods. Furthermore, they can be easily automated and aligned with green chemistry principles, reducing the environmental impact generated in the synthesis of the nanoparticles and their subsequent application. This critical review focuses on the use of MNPs composites in microextraction systems employed for the determination of ECs in liquid environmental matrices over the past 10 years, including pharmaceuticals, personal care products, plasticizers and industrial chemicals and microplastics.