An improved LC-MS/MS method for simultaneous determination of deoxynivalenol and its modified forms in grains and feed.

This study developed an improved LC-MS/MS method for the simultaneous quantification of deoxynivalenol (DON) and its five modified forms (DON-3-G, DON-15-G, 3-ACDON, 15-ACDON, DOM-1) in grains and feeds. Key innovations include diagnostic MRM transitions that resolve co-eluting isomers, along with an optimized ESI- mode that prevents false DON quantification from glucoside adducts. Additionally, a simplified extraction protocol using 1% acetic acid-79% acetonitrile effectively suppressed matrix effects (-6 to -22%) without requiring additional cleanup, thereby enhancing the reliability of current analytical approaches. Validated according to SANTE/11312/2021 guidelines, the method achieved LOQs of 1-30 μg/kg and recoveries of 83.9-103.1%. Analysis of 51 real samples revealed the absence of DOM-1 and DON-15-G in all matrices, a high incidence of DON-3-G in maize (79%), significantly higher frequency and concentration of 15-ACDON versus 3-ACDON, and combined modified DONs reaching 56% of the mean parent DON concentration in maize, necessitating their inclusion in regulatory monitoring.