RAPID SCREENING METHOD FOR THE DETERMINATION OF DIETHYLSTILBESTROL IN EDIBLE ANIMAL TISSUE BY COLUMN LIQUID-CHROMATOGRAPHY WITH ELECTROCHEMICAL DETECTION

A rapid and sensitive screening method for the determination of residues of diethylstibestrol in edible animal tissue is described. The analyte was extracted from the tissue with tert.-butyl methyl ether, reextracted with 1 M sodium hydroxide and further cleaned up by solid-phase extraction with C18 cartridges. Analysis was performed by isocratic elution with a phosphate-buffered mobile phase, methanol-0.05 M phosphate buffer pH 3.5 (67:33), on a Nucleosil 5-mu-m C18 column with electrochemical detection at +0.90 V. The average recovery of trans-diethylstilbestrol in spiked samples is 66%, with a standard deviation of 14% (n = 22) in the range 0.5-2.0-mu-g/kg. The detection limit is 0.1-0.2-mu-g/kg, although at this level other compounds may interfere and give rise to false positive results.