DETERMINATION OF DEOXYNIVALENOL IN WHITE FLOUR, WHOLE WHEAT-FLOUR, AND BRAN BY SOLID-PHASE EXTRACTION LIQUID-CHROMATOGRAPHY - INTERLABORATORY STUDY

A liquid chromatographic (LC) method for determining deoxynivalenol (D ON) in white flour whole wheat flour, and bran at or above the U.S. Fo od and Drug Administration advisory level of 1 mu g/g was evaluated by an interlaboratory study. Test samples of processed wheat (flour and bran) were extracted by blending with acetonitrile-water (84 + 16). Ex tracts were filtered and passed through a solid-phase extraction (SPE) column. The eluate was then chromatographed on a reversed-phase LC co lumn with a water-methanol gradient. DON was measured at 220 nm. Natur ally contaminated white flour, whole wheat flour, and bran samples and spiking solutions of DON to be added to the 3 commodities at 0.5, 1.0 , and 2.0 mu g/g were sent to 4 collaborators in Kansas, Louisiana, Mi ssouri, and Washington states. Three collaborators completed the study . Average recoveries of DON from the 3 commodities spiked at 0.5, 1.0, and 2.0 mu g/g were 94, 87, and 97%, respectively. Within-laboratory relative standard deviations for repeatability (RSDr) ranged from 3.1 to 21.7% and between-laboratory relative standard deviations for repro ducibility (RSDR) ranged from 10.8 to 38.7%. On the basis of the resul ts of this study, the SPE/LC method for DON in white flour, whole whea t flour, and bran was adopted as a peer-verified method by AOAC INTERN ATIONAL.