Determination of deoxynivalenol in whole wheat flour and wheat bran.
A liquid chromatographic (LC) method was developed for determining deoxynivalenol (DON) in whole wheat flour and wheat bran. A 15 g test sample was extracted with acetonitrile-water (84 + 16, v/v) and applied to a Romer MycoSep cleanup column. The eluate was dried and then reconstituted in a 0.1 M phosphate buffer, pH 7.0, and applied to a Vicam DONtest-LC cleanup column. The methanol eluate was chromatographed with a methanol-water (17 + 83, v/v) mobile phase on a C18 column with UV detection at 220 nm. Five replicates at each of 5 fortification levels (0.25, 0.50, 1.0, 2.0, and 4.0 ppm), plus 5 controls, were determined for both whole wheat flour and wheat bran. For flour, the average recoveries were 72.2-91.5% with relative standard deviations (RSDs) of 4.9-18.4%. The intra-assay flour recovery was 82.4% with 9.8% RSD. A 5 replicate sample of naturally incurred wheat had an average of 1.1 ppm DON with 6.7% RSD. For bran, average recoveries of fortified samples were 69.5-99.7% with RSDs of 1.7-18.8%. The intra-assay bran recovery was 81.5% with 8.9% RSD. The limit of detection (about 3x noise) for the method is 0.05 ppm; the correlation coefficient (linearity) was >0.9995. The DON peak was clearly identified and easily integrated in the chromatograms.
Rupp
Heidi S
HS
U.S. Food and Drug Administration, Pacific Regional Laboratory Northwest, Bothell, WA 98021, USA. hrupp@ora.fda.gov
D002021:Buffers; D002853:Chromatography, Liquid; D004043:Dietary Fiber / Q000032:analysis; D005433:Flour / Q000032:analysis*; D013058:Mass Spectrometry; D012015:Reference Standards; D012996:Solutions; D012997:Solvents; D013056:Spectrophotometry, Ultraviolet; D014255:Trichothecenes / Q000032:analysis*; D014908:Triticum / Q000737:chemistry*
D002021:Buffers; D004043:Dietary Fiber; D012996:Solutions; D012997:Solvents; D014255:Trichothecenes; C007262:deoxynivalenol