Gas Chromatographic Method for Quantitation and Confirmation of Trichothecenes in Wheat

Abstract

Abstract A capillary gas chromatographic method with flame ionization detection was evaluated for quantitation and confirmation of 7 trichothecenes known to occur in grain crops. The method was applied to spiked and naturally contaminated wheat samples. Samples were extracted with methanol-aqueous KCI. After clarification with ammonium sulfate and partition to chloroform, a charcoal–alumina–Celite column cleanup was used. Heptafluorobutyryl derivatives of trichothecenes were quantitated with a methyl eicosanoate internal standard. Confirmation of identity was achieved by comparing the chromatographic behavior of suspected samples with those of standards after acetylation and hydrolysis for group A trichothecenes, and acetylation and reduction for group B trichothecenes. Limits of detection ranged from 0.1 to 0.5 μg/g. Average recoveries for diacetoxyscirpenol (DAS) and nivalenol (NIV) determined at 7 levels of contamination were 88 and 93%, respectively. Average recoveries for deoxynivalenol, NIV, DAS, T2 tetraol, and T2 triol at a single level of contamination were 85,87,83,87, and 91 %, respectively. Relative standard deviations for determinations of naturally contaminated samples ranged from 2.8 to 12.9%. For spiked wheat samples, the relative standard deviations ranged from 4.6 to 11.9%.