Fumonisins are toxins (mycotoxins) produced by fungi (Fusarium) that are frequently identified in corn (maize).  Mycotoxins are toxic to animals and humans and contaminated crops are discounted or destroyed.  Clay feed additives effectively bind and reduce the toxicity of aflatoxins and might be used to reduce the toxicity of other mycotoxins.  Adsorption of mycotoxins to feed additive surfaces can limit the bioavailability and toxicity of contaminated feed that has been ingested.  An enzyme-linked immunosorbent assay (ELISA) method will be used to measure fumonisin concentrations in adsorption isotherms from water and from aqueous corn meal.  Unlike the aflatoxins, fumonisins are acidic, anionic compounds that would not likely bind to the negatively-charged surfaces of natural clay minerals.  Hence, modified clays, cationic synthetic clays, or other materials that might bind fumonisins and reduce the toxicity will be examined.  Various potential fumonisin sorbents will be tested and compared to cholestyramine resin, which has reduced fumonisin toxicity in animal feeding studies.  Cholestyramine is an anion exchange resin and pharmaceutical product, which is used to treat human medical conditions.  Cholestryramine is far too expensive for practical use as a feed additive and alternative materials must be identified.  Chitosan is a non-toxic biopolymer derived from chitin, which is the structural polysaccharide found in the exoskeletons of crustaceans and insects.  Chitosan is a modified form of chitin with amine groups that protonate in acidic solutions to yield a positive charge and might have anion exchange properties and bind fumonisins like cholestryamine.