Fluorescence polarization immunoassays for the determination of trichothecenes and their modified forms in wheat.

Deoxynivalenol (DON), T-2 toxin (T-2) and HT-2 toxin (HT-2), due to their incidence and toxicity, are the trichothecenes of major concern for cereals and cereal-based products. Moreover, natural occurrence of modified forms of DON, such as 3-acetyl-deoxynivalenol (3Ac-DON), 15-acetyl-deoxynivalenol (15Ac-DON), and deoxynivalenol-3-glucoside (DON3G), and of T-2 and HT-2, such as T-2 glucoside (T-2G) and HT-2 glucoside (HT-2G), have been reported by several authors. The development of analytical methods for the simultaneous detection of these mycotoxins and their modified forms, also expressed as the sum, is highly requested since it could meet future requirements of European or international regulations. For this reason, two fluorescence polarization immunoassays (FPIAs) have been developed and in-house validated for the rapid (<15 min) and simultaneous determination, expressed as sum, of: (i) DON, 3Ac-DON, 15Ac-DON and DON3G in wheat and (ii) T-2, HT-2, T-2G and HT-2G in wheat. The developed FPIAs showed good analytical performances in terms of recovery (89-112%) and precision (<=13%) fulfilling the EU criteria for acceptability of an analytical method for the determination of relevant native forms. The assays have been also validated according to the harmonized guidelines for the validation of screening methods (Regulation EU, No 519/2014). The satisfactory analytical performances, in terms of precision (repeatability <=9%, within-laboratory reproducibility <=13%), cut-off levels and rate of false positive results (<0.1%), confirmed the applicability of the proposed FPIAs as methods for the high-throughput screening of these trichothecenes and their modified forms in wheat. Moreover, it is highlighted that the developed FPIAs are low-cost, portable, can be automated and do not require a high level of technical skills.