Magnetic nanostructures for marine and freshwater toxins removal.

Marine and freshwater toxins contaminate water resources, shellfish and aquaculture products, causing a broad range of toxic effects in humans and animals. Different core-shell nanoparticles were tested as a new sorbent for removing marine and freshwater toxins from liquid media. Water solutions were contaminated with 20 µg/L of marine toxins and up to 50 µg/L of freshwater toxins and subsequently treated with 250 or 125 mg/L of nanoparticles. Under these conditions, carbon nanoparticles removed around 70% of saxitoxins, spirolides, and azaspiracids, and up to 38% of diarrheic shellfish poisoning toxins. In the case of freshwater toxins, the 85% of microcystin LR was eliminated; other cyclic peptide toxins were also removed in a high percentage. Marine toxins were adsorbed in the first 5 min of contact, while for freshwater toxins it was necessary 60 min to reach the maximum adsorption. Toxins were recovered by extraction from nanoparticles with different solvents. Gymnodinium catenatum, Prorocentrum lima, and Microcystis aeruginosa cultures were employed to test the ability of nanoparticles to adsorb toxins in a real environment, and the same efficacy to remove toxins was observed in these conditions. These results suggest the possibility of using the nanotechnology in the treatment of contaminated water or in chemical analysis applications.

Detoxification agents based on magnetic nanostructured particles as a novel strategy for mycotoxin mitigation in food.

Mycotoxins are toxic compounds that can be present in feed, food and beverages. In this work, 25 magnetic nanostructured materials were developed to remove the main types of mycotoxins from liquid food matrices. The efficiency for binding mycotoxins from contaminated aqueous solutions was studied. Nanocomposites (diameters lower to 15 µm) composed of mixtures of activated carbon, bentonite and aluminium oxide were able to eliminate up to 87% of mycotoxins with an adsorption efficiency of 450 µg/g. On the other hand, spheres with sizes below 3 mm and composed by biopolymers and activated carbon or graphene oxide removed up to 70% of mycotoxins (adsorption of 598 ng/g). These particles were tested for beer detoxification, and spheres composed of alginate and activated carbon or pectin maintain the ability to eliminate toxins from this beverage. Hence, this technology could be a useful tool for the food industry.