Determination of zearalenone in corn by high pressure liquid chromatography and fluorescence detection

A method is reported for determining zearalenone in corn at levels as low as 10 ng/g. Samples are extracted with chloroform-water and cleaned up by liquid-liquid chromatography, and the zearalenone is detected by a fluorescence detector after separation by reverse phase high pressure liquid chromatography (HPLC). Recoveries of zearalenone added to corn at levels from 10 to 200 ng/g averaged greater than 89%. In addition, a confirmation procedure is described which involves sequential HPLC analysis of the sample and a zearalenone standard, using 4 different excitation wavelengths and comparing fluorescence responses obtained. This method was successfully applied to the analysis of 11 samples of cornmeal; zearalenone was detected in 9 of the samples at levels from 11 to 69 ng/g.