Immunochemical Methods for Fumonisins in Corn

Abstract

An enzyme-linked immunosorbent assay (ELISA) and an immunoaffinity column (IAC) cleanup procedure have been successfully applied to the determination of fumonisins in corn. The performance of the ELISA was evaluated by comparison to a reference high-performance liquid chromatographic (HPLC) method. The IAC procedure was coupled with HPLC determination. The recoveries of fumonisin B 1 from corn spiked at the 1,2, and 4μg/g levels were 73-106, 79-83, and 64-92% for the ELISA, IAC, and HPLC methods, respectively. The accuracy and precision of the methods compared favorably. In the comparative studies using naturally contaminated corn samples, the ELISA results were 2-100% higher than those determined by HPLC. The immunoaffinity procedure results were about 71% of the levels observed using HPLC.The fumonisins are a group of structurally related mycotoxins, which are secondary metabolites produced on corn by Fusarium moniliforme (1,2), Fusarium proliferatum (3), and several other flingi (4,5). Of the known naturally occurring fumonisins, fumonisins B l (FB X ) and Bj (F^ ) are the most abundant (6). In the United States the FB 1 fFB 2 ratio in corn is about 3:1 (7). was found to cause equine leukoencephalomalacia (2), porcine pulmonary edema (8), and rodent hepatotoxicity (9). Cattle and poultry can also be affected, but are not as susceptible to the mycotoxin as horses and swine. The Mycotoxin Committee of the American Association of Veterinary Laboratory Diagnosticians recommends that the total intake of FB! be limited to less than 5 μg/g in the non-roughage diet of horses, 10 μg/g in the total diet of swine and 50 μg/g in the feed for cattle and poultry (10).