Evaluation of an extraction method and spin column cleanup procedure for Fusarium mycotoxins and their masked derivatives from grain matrix

Fusarium mycotoxins in foodstuffs at levels in violation of allowed legal limits belong to the most frequently occurring type of food contamination. Out of the large variety of known mycotoxins, deoxynivalenol (DON), zearalenone (ZEN), and the T-toxins are the most prevalent and are responsible for extensive and recurring economic damage. For ensuring consumer safety, it is required to continually identify faster, simpler and more reliable analytical methodologies. In the present work, miniaturized centrifugation (spin) columns for the extraction of mycotoxins from grain samples were investigated, with a focus on matrix removal, applicability of different extraction solvents, and recovery of mycotoxin. The method was further extended to the extraction of naturally occurring DON and ZEN conjugates (masked mycotoxins). The spin column method was observed to routinely provide a total matrix reduction of >90% from typical wheat samples in a single centrifugation step. The use of H2O/ACN (20/80; v/v) as an extraction solvent provided non-masked DON, ZEN and T-toxin recoveries of greater than 80%. For the masked DON and ZEN conjugates (DON-3-glucoside and ZEN-14-sulfate), recoveries were lower. Overall, the evaluated miniaturized spin column procedure enabled rapid loss-free extraction of unconjugated mycotoxins from conventional grain matrix and a significantly reduced matrix load in the extracts.