Selectivity of commercial immunoaffinity columns for modified forms of the mycotoxin 4-deoxynivalenol (DON)

Commercial immunoaffinity columns (IACs) are today available for all major mycotoxins. However, manufacturers give usually no or very limited information on the epitope, i.e. the specific part of the toxin molecule that binds to the antibody. 4-Deoxynivalenol (DON) is a trichothecene mycotoxin that is produced by plant pathogenic field fungi and is regulated in many countries worldwide. DON was shown to be biotransformed via different metabolic pathways, and thus many different biotransformation products may be found in different products or organisms. In addition, several structurally similar mycotoxins may co-occur with DON. We compared five commercial IACs for their retention of a range of DON derivatives modified in the C-3, C-8, C-10, C-13 or C-15 positions, as well as nivalenol (NIV) and T-2 tetraol. The DON-derivatives were deepoxy-DON, DON 3-, 8- and 15-O-β-d-glucuronides, 3- and 15-O-acetyl-DON, DON-3-O-β-d-glucoside, 10- and 13-cysteinyl-adducts of DON, and the 13-mercaptoethanol and 10,13-dimercaptoethanol adducts of DON. The C-3 derivatives and deepoxy-DON were retained by most of the columns. Only one of the five IACs retained C-15 and C-8 derivatives, but it did not retain C-3 derivatives or deepoxy-DON. The antibodies in two of the IACs bound C-10 conjugates, but C-13 derivatives were not retained by any of the columns. This study shows that all of the antibodies in commercial IACs bind a range of DON derivatives, especially those that are modified at C-3. NIV was retained by three of the columns, and T-2 tetraol was partially retained by one IAC.