ONE-STEP SOLID-PHASE EXTRACTION CLEANUP AND FLUOROMETRIC ANALYSIS OF DEOXYNIVALENOL IN GRAINS

A rapid, quantitative, inexpensive, efficient method was developed to determine deoxynivalenol (DON) in wheat, barley, corn, wheat middlings , wheat flour, bran, malted barley, and oats. Samples are ground and e xtracted with acetonitrile-water (86 + 14). A portion of the extract i s cleaned up by passage through a MycoSep No. 225 column, evaporated t o dryness, and derivatized with zirconyl nitrate and ethylenediamine i n methanol. The resulting fluorescent derivative of DON is identified and quantitated with a calibrated fluorometer containing a broad wavel ength pulsed xenon light source. This method quantitated DON concentra tions from 0.5 to 50 ppm without dilution and was linear when applied to samples of noncontaminated wheat spiked at 0.5, 5, 10, 25, and 50 m u g DON/g. Correlation coefficients of the method with LC for multiple analyses (n greater than or equal to 14 for each commodity) applied t o wheat, corn, barley, wheat flour, and wheat middlings were 0.99, 0.9 9, 0.99, 0.93, and 0.98, respectively. Individual analyses were conduc ted in < 30 min, and 24 samples were analyzed in 2 h.