Doehlert matrix design for optimization of the determination of bound deoxynivalenol in barley grain with trifluoroacetic acid (TFA)

Fusarium head blight (FHB) is an impediment to barley production in many regions of the world. Tricothecene toxins, associated with FHB-infected grain, particularly, deoxynivalenol (DON), pose a serious threat to human and animal health. Recent research has suggested that a portion of the DON present on grain is bound and escapes detection through conventional determination. The objective of this study was to optimize a method for determination of nonextractable DON in barley grain using trifluoroacetic acid (TFA). A Doehlert matrix design was performed to determine the optimal conditions for time, temperature, and TFA concentration. These conditions were treated with 1.25 N TFA in 86:14 acetontrile/water for 54 min at 133 degrees C. Cleanup, derivatization, and determination of DON by a gas chromatography electron capture detector (GC-ECD) was as normal. Treatment of the test sample resulted in the release of an additional 58% DON under the optimized conditions and an increase of 9-88% in a set of verification samples.