90 A rapid fluorometric method for the determination of deoxynivalenol in barley.

S. Kruger, B. MCALICE, and B. Kohn. VICAM L.P., Watertown, MA 02472.

The Fusarium toxin, deoxynivalenol, is found worldwide in cereal grains causing feed refusal in animals and gastrointestinal problems in humans. In an effort to provide better methods of testing, a new technique for the detection of deoxynivalenol is presented. This rapid and accurate method uses immunoaffinity column chromatography for isolation and fluorometry for quantification. We worked with a major malter who provided GC/ECD results generated using the standard method of Tacke and Casper. Barley samples for the fluorometer method were extracted in 100% water and filtered. A developer solution was mixed with an eight mL aliquot of the extract and incubated for five minutes. Subsequently, this mixture was applied to the immunoaffinity column. After washing, the column was eluted with 100% methanol into a glass cuvette and the eluate was read on the VICAM fluorometer. Throughout performance testing against the GC/ECD standard, the VICAM method provided high quality results. For 225 naturally contaminated barley samples within the assay range (0.50–5.0 ppm), the GC/ECD method had a mean value of 2.09 ppm while the VICAM results had a mean value of 2.15 ppm with an average RSD of only 23%. In addition, the linear regression curve of the 225 results shows a reasonable correlation (r = 0.80). This comparison shows the ability of this new technique to provide both rapid and accurate results for deoxynivalenol content in a cereal grain when compared to a standard GC/ECD method. In contrast to GC/ECD, this method of comparable accuracy is suited to field use.