Assessment of Immunochemical Methods for the Analysis of Trichothecene Mycotoxins in Naturally Occurring Moldy Corn

Abstract

Abstract The efficacy of various immunochemical methods for simultaneous analysis of different trichothe-cene mycotoxins in corn samples naturally contaminated with various Fusarium molds was evaluated. Antibodies against either T-2 tetraol tetraacetate (T-2-4ol-4Ac) or deoxynivalenol triacetate (Tri-Ac-DON) were used in the enzyme- linked immunosorbent assay (ELISA) and radioimmunoassay (RIA) for total type A and total DON-related trichothecenes (TCTCs), respectively. Specific antibodies against T-2 toxin were used in an RIA for analysis of T-2 toxin alone. Analytical recoveries of T-2 toxin analyzed as T-2-4ol-4Ac by ELISA and T-2 toxin by RIA at 10-200 ppb were 83.5-123% and 81.8-110.6%, respectively. T-2 toxin accounts for about 30% of total type A TCTCs by both liquid chromatography (LC)-ELISA and RIA methods. The correlation coefficients (r) of total type A TCTC levels versus T-2 toxin level by RIA was 0.725 (p < 0.0001). A good correlation (r = 0.84 and p = 0.04) also was found for T-2 toxin levels obtained by LC-ELISA and RIA methods. In addition to T-2 toxin, HT-2 toxin, diacetoxyscirpenol, and T-2 tetrol were found in samples containing high levels of type A TCTCs by LC-ELISA. For analysis of DON alone, samples were treated with a Sep-Pak C18 cartridge to remove other acetylated DONs before RIA. Recovery of DON after the C18 cartridge treatment was 90%. Overall analytical recoveries of DON as Tri-Ac-DON (sample with no C18 treatment) and DON alone (with C18 treatment) at 10-500 ppb were 81.3-94% and 72.7-104%, respectively. RIA revealed that DON accounts for about 50% of total DON-related TCTCs. The coefficient of correlation between total DON-related TCTCs and DON levels was 0.84 (p < 0.0001).