Effect of time, temperature and solvent on the stability of T-2 toxin, HT-2 toxin, deoxynivalenol and nivalenol calibrants

The influence of solvent, storage time and temperature on the stability of the trichothecene mycotoxins T-2 toxin (T-2), HT-2 toxin (HT-2), deoxynivalenol (DON) and nivalenol (NIV) was investigated. Toxins in acetonitrile, ethyl acetate or as thin film were stored in sealed glass ampoules at -18, 4, 25 and 40°C for up to 24 months. Samples were analysed by HPLC with UV detection. The results show that acetonitrile was the preferred solvent and no significant ( t 0.95 -test) decomposition occurred for any of the four trichothecenes when stored for 24 months at 25°C or 3 months at 40°C. T-2 and HT-2 in ethyl acetate or as thin film were also stable under the same conditions. DON and NIV in ethyl acetate or as thin film were stable for up to 24 months at -18°C, but a significant decomposition of DON and NIV in ethyl acetate was observed for both toxins after 24 months of storage at 4°C and after 12 months at 25°C. When stored as thin film, a significant trend of decomposition of DON occurred after 24 months of storage at 4°C and after 6 months of storage at 25°C. A significant decrease of NIV stored as thin film was observed after 9 months at 25°C. In conclusion, acetonitrile was the most suitable solvent for long-term storage of T-2, HT-2, DON and NIV.