An Efficient Gas Chromatography-Mass Spectrometry Approach for the Simultaneous Analysis of Deoxynivalenol and Its Bacterial Metabolites 3-keto-DON and 3- epi-DON.

Deoxynivalenol (DON) is one of the major toxic secondary metabolites produced by Fusarium fungi in cereal grains. Among the many promising strategies of DON detoxification are the microbial and enzymatic ones, which transform DON to nontoxic DON metabolites. Thus, proper analytical methods are needed for those DON metabolites. In this study, a robust gas chromatography-mass spectrometry (GC-MS) procedure was developed and validated for the simultaneous analysis of DON and two of its bacterial metabolites, 3-keto-DON and 3- epi-DON. The procedure involves a straightforward vacuum drying and derivatization step before the subsequent GC-MS analysis. Following the optimized protocol, DON and these two metabolites were separated on a capillary column within 15 min. The linear ranges for the these compounds were 10 to 2,000 ng mL-1 with correlation coefficients >0.99. For DON, 3- epi-DON, and 3-keto-DON, the limits of detection were 0.8, 3.0, and 0.05 ng mL-1 , and the limits of quantification were 2.6, 10.0, and 1.0 ng mL-1 , respectively. For all three compounds, the obtained relative standard deviation was 1.2 to 5.5%, and the recovery rates were 89.5 to 103.6%. The developed method was further validated by analyzing DON metabolites resulting from the biotransformation of DON initiated by cell-free lysates of the bacterium Devosia mutans 17-2-E-8. The developed protocol was sensitive, precise, accurate, and robust for the determination of DON, 3- epi-DON, and 3-keto-DON in liquid media and potentially other complex matrices without interference from other compounds.