High pressure liquid chromatography of zearalenone in cereals

A high pressure liquid chromatographic method has been developed for determining zearalenone in cereals. The sample is extracted with phosphoric acid and chloroform. The extract is cleaned up by washing on a silica gel column with benzene-hexane or cyclohexane-ethylene dicholride-ethyl ether and eluting with chloroform, and further purified by extracting into alkaline solution, washing with water, adjusting pH, and back-extracting into chloroform. Zearalenone is determined by using a liquid chromatograph with 2 columns in series packed with Spherisorb 10 micron ODS and with an ultraviolet detector set at 236 nm. The detection limit of the method is 2 microgram/kg. Recovery is about 90% when benzene-hexane is used in the washing step and about 80% when cyclo-hexane-ethylene dichloride-ethyl ether is used.