Efficient Method for Determination of Deoxynivalenol and Nivalenol in Wheat and Barley by Gas Chromatography

We have developed an analytical method for rapidly determining deoxynivalenol (DON) and nivalenol (NIV), typical mycotoxins in cereals infected by Fusarium spp., in wheat and barley. Since we used a solvent of high polarity and water to elute columns of mixed alumina-charcoal-celite and Amberlite for extraction and clean-up, we were able to omit partition and dehydration processes. The separated mycotoxin was determined by ECD-gas chromatography after trimethylsilylation. The limits of determination of DON and NIV are 12ng/g, and that of fusarenon-X (F-X) is 24ng/g. These limits are adequate for economic screening analysis. When DON and NIV were added to wheat and barley at the 120ng/g level and F-X at the 240ng/g level, the recoveries were 101 and 95%, 93 and 92%, and 96 and 96%, and the coefficients of variation were 2.9 and 3.4%, 3.7 and 2.4%, and 3.5 and 3.4%, respectively. When F-X was detected by this method, its identity was confirmed by mass chromatography. So far we have not detected F-X in cereals. Further studies are in progress. This method was designed for rapid determination of wheat and barley, but should also be applicable to the analysis of mixed feed. It is easy to change the limits of determination by changing the quantities of sample and solvent. One analyst can analyze 8 samples in a day, and two analysts, 20 samples.