Simultaneous analysis of nivalenol and deoxynivalenol in cereals by liquid chromatography

A sensitive method is described for determination of nivalenol (NIV) and deoxynivalenol (DON) in cereals by using reverse phase liquid chromatography and UV detection at 222 nm. The sample is extracted with acetonitrile-water (85 + 15) and an aliquot is purified by passage through a combined column of cation exchange resin and alumina-carbon (20 + 1). Analysis at this stage is possible with some samples but the method recommends passing an aliquot through a carbon minicolumn after evaporation and solubilization in methanol. Interference from coextracted compounds at this point is negligible. Recoveries of both NIV and DON from spiked extracts taken through the full method were in the range 83-94%. The relative standard deviation, based on 5 replicate determinations from each of 2 corn samples, was approximately 5% for both NIV and DON. With a 10 microL injection, the minimum contamination (3 X signal/noise ratio) able to be detected in cereal samples was about 0.015 micrograms NIV/g and 0.05 micrograms DON/g. The cleaned up extracts are also suitable for analysis by gas chromatography.