A high pressure liquid chromatographic method for the quantitation of sub-microgram amounts of zearalenone (F-2) in agricultural products.

A highly sensitive and reliable method for the quantitation of sub-microgram quantitaties of zearalenone (F-2) residues in corn, corn oil and mixed feed is described. The isolation of this mycotoxin from a mixed solvent extract involves partitioning of the alkali soluble components from a chloroform solution, followed by acidification and extraction of organic components into chloroform, a silica gel column clean-up and analysis by high pressure liquid chromatography using a ultraviolet (UV) detector at 280 nm. The limit of detection of the instrument is shown to be 2.5 ng and that of the method is 100 ppb. The percent recoveries of zearalenone in corn is found to be 72.1 +/- 6.0 at the levels between 0.1 and 1.0 ppm, in corn oil 72.6 +/- 8.8 at levels 0.25 and 1.0 ppm and in pig starter 67.3 +/- 4.5 at 1.0 ppm level. In the case of two field samples, the reproducibility of analysis is very good and the mycotoxin contents are shown to be 11.5 +/- 0.26 and 0.61 +/- 0.07 ppm.